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Last Post 17 Nov 2016 05:26 PM by Fair
Vorshlag BRZ Project Build Thread
|28 Aug 2012 07:38 PM
BRZ Project Introduction - August 28, 2012: We here at Vorshlag have had a cautiously optimistic view of the FT-86 Subaru/Toyota RWD joint venture starting 3+ years ago when the car was first announced. As soon as the pre-production cars started circulating the USA (January-February 2012), we went to a local Subaru dealer and measured all sorts of things (which you can read about in my February 2012 post here).
We noticed several things about the pre-production car pretty quickly, such as the many similarities with production Subaru model parts and some notable exceptions. The placement of the engine was uncharacteristically far back for a Subaru, which helps explain its more ideal 56% front weight bias.
The basics looked good, but as with any production built car, it looked to have some compromises that we felt we can improve on. We had a quick pow-wow and came up with some plans, then the same weekend we took measurements on the blue pre-production BRZ, Matt here at Vorshlag placed an order for a 2013 Subaru BRZ Limited in the same World Rally Blue.
Months went by with his Dallas based dealer without any ETA for his order, while other BRZs were arriving for weeks at this same dealership. He lost patience with this process, cancelled his order, and found an identical car sitting on a lot in the state of Connecticut. His car finally arrived on July 18th and he began daily driving it while we worked on a Subaru build for Pikes Peak. Once that STi project was finished and the race was over, we finally got a chance to get his BRZ into the shop to corner weigh it, remove a few parts and scale them, and measure the suspension in more detail.
Purpose & Goals
Like we often do when a new chassis comes out, this particular BRZ is going to be a test mule for new Vorshlag parts. It will be primarily a daily driven street car, but also set-up to run in the SCCA autocross class called "STR" (until the Solo Events Board wises up and moves it to the STX class, where I think it belongs). The rules for that class limit the tire width to 255mm and the wheel width to a maximum of 9" wide. The suspension options are fairly open so we can do springs, coilover shocks, camber plates, bushings, some control arms, swaybars, and more - so long as we don't move any of the suspension pick-up points. Engine mods are pretty restricted, but full length headers are legal (with cat placement rules) as well as a lightweight cat-back exhaust, a cold air intake and engine tuning. We will either make these items or source them from other vendors.
Vorshlag camber plates for use with OEM springs require a new upper spring perch made with a modified stock or CNC aluminum perch
One of the first parts that we will test are our FT86 camber plates (which we've already sold for many coilover equipped FR-S and BRZ models). This car's front spring diameter is unique for Subaru and will require a new upper spring perch design to work with the FT86 chassis OEM front springs or OEM-style lowering springs. All of our camber plates include a new upper spring perch with a sealed radial bearing inside. Swift Springs has new Sport lowering springs coming from Japan that we will install as soon as they arrive. Whiteline has some bushings and bars that will be added to the car when they are available, too.
This weighing still had all of the "trunk junk", 3/4 tank of gas, and came in at 2775 lbs.
We don't plan on making this into a gut-crushing race car, but a better handling, fun street car and hopefully faster for autocross and track use. We had originally planned on testing the first pre-production AST 4150 monotube coilovers for the FT86 chassis, but they were sent to another dealer, so we're waiting for the second test set. As soon as we get coilovers on the car we will post in this thread with our impressions. The corner weight shown above shows 55.9% weight over the front axles, which is exceptional for any Subaru we've ever weighed. Many times their FWD or AWD models approach 60/40 weight bias, but the lack of AWD allowed the engineers to move the engine and transmission back (and low) for a better F/R bias and lower Center of Gravity (CG). We plan to lower that 2775 pound initial weight and will show the weight loss for each part we replace.
First Mod: Better Wheels & Tires
Look how narrow and "tucked" inboard the factory wheels and tires look on this wide sports coupe.
The first upgrade for Matt's car was a wheel and tire change, since any kind of competition on the factory rolling stock was going to be an exercise in frustration. This is a great handling car from the factory, for sure, but the one major deficiency of this car that almost all car magazines have agreed upon is the factory tires. The relatively narrow 215/45/17 Michelin Primacy HP tires are what come on the European model Toyota Prius, which tells you it is about as far from a performance tire as they come. This is a low rolling resistance tire, first and foremost.
I got a lot of grief earlier this year for calling the factory BRZ tires "Prius tires" (even though that's exactly what they were), and at the time it was from people who had never seen or driven these cars. I suspected at the time that these skinny, low grip tires would make the cars test poorly by the car mags (it did) and be a significant hindrance to the on-track performance of this new model. Once Car&Driver (article) got their hands on the car, they felt the same way and simply swapped the Prius tires for an identically-sized Dunlup Direzza Star Spec. They dropped over 2.3 seconds on their one minute and thirty second test course (article). These Primacy tires will help you eek out another ~1/2 mpg better on the highway than a wider performance tire, if you are a Hyper Miler. If you are an automotive performance enthusiast, you will very likely want to make a wheel and tire upgrade a high priority.
I've already seen dozens of BRZ and FR-S owners upgrading to 7.5" and 8" wide wheels, but we at Vorshlag have never been shy about stuffing as much wheel width under a car as possible. A larger wheel can support a larger tire and with a larger tire you can get more grip! Tire heights do have to be considered, but a taller tire can have an advantage in autocross situations where an extra 1-3mph in 2nd gear can make all the difference. I only stop adding wheel width when we get tire rub, and even then I'll roll a fender and try to get more if we can. After some early measurements before Matt's car arrived, then a bit of a gamble, we went with a 17x9" aluminum wheel that has an +42mm offset front and rear. These bolted on with perfect inboard clearance. The rear can take more wheel width, but the front is pretty maxed out until we can get some more negative camber with our camber plates. This is definitely a car where a "square" wheel set-up will be best for street/competition usage (same width front and rear).
Now I will point out that going from the stock 17" wheel diameter up to 18" wheel diameter gains you nothing performance wise but higher cost & weight on both the wheel and tire. If you keep the same tire diameter (to not alter gearing or speedometer) this +1 wheel diameter change would result in a shorter sidewall height, making the ride quality worse and the additional weight can adversely affect handling. That was failure number one in Car&Driver's article when they started messing with wheels and tires beyond just slapping better tires on the stock wheels. They used an 18x7.5" wheel (still too narrow) and a tall 235/40/18 Dunlop tire (almost a full inch taller in diameter) and slowed down 0.7 seconds from the 215/45/17 Dunlop tires on that same road course. Classic mistake where upping wheel diameter for no reason other than style bit them in the ass. Don't fall for the "+1" trap, just stick with 17" wheels on your BRZ or FR-S for the best performance. Competition racers might even look at 16" wheel diameters, which should easily clear the small-ish brake rotors, but trying to find wide performance tires in 16" wheel diameter is just about impossible these days, so back to 17's you go.
The tires installed were 245/40/17 Michelin Pilot Super Sport's. Personally, I would have used a 255/40/17 tire from Hankook (RS-3) or Dunlop (Direzza Star Spec), but Matt wanted to test this new PSS model. Since Michelin doesn't make a 255/40/17 in the new PSS yet, he bought the widest he could find in the right diameter (to not alter gearing), which was 245/40/17.
This 17x9 wheel is a big performance boost, being a full two inches wider than the somewhat heavy 17x7" stock wheels (20.4 lbs). The addition of wider aftermarket wheels and 30mm wider 245/40/17 tires was still a total wash with regards to weight: the original equipment 17x7" wheel and 215/45/17 tire was was 41.3 lbs, while the 17x9" wheel and 245mm PSS tire weighed 41.4 lbs. I've seen this same sized 17x9" wheel weigh as much as 2 pounds lighter per corner, so there could still be weight loss to be had here if someone makes an uber-light fitment for this car. This particular 17x9" is not a wheel we can sell (it is exclusive to another wheel dealer), so we will evaluate this sample set and come up with an alternative that we can market and sell, soon. From our search of many wheel catalogs there are barely any quality 17x9" wheels right now that fit this car (5x100mm bolt pattern is the tough variable), but I'm sure there will be if this car stays as popular as it is now.
I drove this car last week on the new rubber, which was the first time I have driven any car on the Michelin PSS, and I was impressed. They were MUCH quieter than Hankook RS3's or Dunlop Star Spec's (which end up being on about 80% of our customers' cars). Lots of dry grip, responsive as hell (it helped that these were 245mm tires on 17x9" wheel) and the ride was excellent. Matt didn't want to go with the RS3 or Dunlop in 255/40/17, because he's owned and driven on both of those tires and was tired with the noise and poorer street ride they tend to provide. However, for a "street tire" autocross class or track use I would use one of those other two models in a heartbeat.
The 2700 Calorie BRZ Diet
As usual, this car came in significantly heavier than the earlier claims made by the manufacturer, forum fan boys and magazine speculation. I'm not picking on this car in particular because this ALWAYS happens. Before the Honda S2000 was released many people bragged that it would only weigh 2400 pounds, but it came out at over 2850. It's an old story - the promise of a fly weight car that ends up being heavier when the actual production model hits the showrooms. Crash standards, luxury options, and emissions equipment all conspire to add pounds.
The FT86 chassis was supposed to be 2500-2600 pounds and it's nearly 2800, so we will focus some of our efforts on lowering that number. Each time we remove a factory part we will show the weight, as well as whatever goes on to replace it. Lower weight means more performance in every vector, be it cornering, braking or forward acceleration. 5 pounds here, 10 pounds there - it will add up.
Matt left his BRZ unattended when he went to lunch one day last week. It was on the lift so we could measure some things, so I pulled the exhaust off for a quick check (then sent him a text with pictures of his car in pieces - hehe!). The muffler was surprisingly light, as was the entire after-cat system. At a hair over 38 pounds, the after-cat exhaust is not a place where we are going to find a big weight loss. A typical exhaust on BMWs we work on can exceed 90 pounds, and dropping 30-40 out with a lightweight racing style exhaust and muffler on those is common... but that will not be the case here.
That suitcase-sized rear muffler is the heaviest part of the system, of course, but must not have much "heavy" inside. I was pretty bummed, thinking this was be a good place to lose weight. Most of the aftermarket mufflers we use are still 8-13 lbs, so there are still some weight savings to be had. The stock exhaust is quiet and could be restrictive - we shall see.
We did see a lot of steel in the control arms and such, which could be replaced with aluminum by the aftermarket or maybe a future, rumored "STI" model, like the STI model Imprezas often do. We will check what this stuff weighs and see what we can do. The factory exhaust manifolds might hold some pounds we can drop, so when we get a chance to pull those off we will get a weight and think about a custom header. Might unleash some power, too.
I have owned and driven a wide variety of sports coupes and roadsters and the BRZ does not disappoint. The normal complaint with a Miata that I run into with my height is a general lack of headroom, but that is not a problem on the FT86 chassis. The interior is roomy and the greenhouse has excellent visibility, with the exception of the B-pillar creating a bit of a blind spot on the left side (this can be mitigated with proper side mirror set-up). The chassis feels tight and has none of the cowl shake and rattle I always feel in a Miata or other roadsters. The car rides well and handles like a Miata (except less roll), with instant steering response and very neutral handling - especially on the 245 Michelins stretched out on the 17x9" wheels.
The interior quality is exceptional for a car in this market niche, and the radio sounds really good. The pedals, steering wheel and shifter are all placed perfectly, other than an unusual angle of the wheel relative to the dash when I have it adjusted so that I can see the gauges. It just looks a little off, but I don't notice it once I start driving. Exceptionally good seats that I would not be in any rush to replace, which is rare. The back seat area is more of a package shelf than room for even tiny humans, but this still makes the car more useful around town than something like a Miata. I like the fact that it has a trunk and not a hatch back, too.
We know nothing about this turbo kit, so please contact Dynosty with any questions! This is simply a reference for the stock power level.
Having driven it hard on the street I can say that I do like it, but of course I wish it had more power. The 200 horses that this motor is rated at are all up top, and you have to wind it up to get it really going. It doesn't help that my daily driver has nearly three times the horsepower, so I guess I am a bit biased when you hand me a car that makes around 155 whp. Drive it hard enough and around several corners on some grippy tires and you forget all about the lack of power, because horsepower was never what this car was about. It is a true driver's car, with a quick steering feel, easily darting around back roads or carving corners on a purpose built road course. Low(ish) weight and lower cost consumables, great controls with proper manual gearbox shift feel.
This car really is a blast to drive as long as you don't have a Viper or Z06 sitting in your garage, and I think Subaru and Toyota have a hit on their hands. The look and performance of the FT86 appeals to a fairly diverse audience and will likely turns heads for quite a while. After my very first drive in this car, I parked at a restaurant and had two random older gentlemen walk up and ask me "well, how is it!?" They couldn't take their eyes off the car and knew a lot about it, which was odd for "non-car-guys".
Some of the deficiencies I point to in my post exist because they have to sell it to just about anyone, from a grandmother to a teenager, so I get why it has the compromises it has. I am fairly confident we can improve upon the various performance aspects of this car for the true car enthusiasts that want to buy this car: to make it lighter, handle better, generate more grip, and maybe even accelerate harder.
Stay tuned and let's see what we can do.
|28 Aug 2012 11:02 PM
Nice choice with the PSS!
|02 Oct 2012 07:54 PM
Project Update for October 2, 2012: Well a lot has happened in the last 4 weeks since my first BRZ post. We've been super busy with some big race weekends, and have been working on several LS1 swaps in-house among other cars. Still, we have made some strides on this FT-86 project. First, the SCCA classing news.
FT-86 Twins Classed In STX!
If you are interested in SCCA autocrossing this FT86 chassis, there were some notable things said and seen at the 2012 SCCA Solo Nationals. We noticed a number of FR-S/BRZ cars entered in C Stock and a few in Road Tire, but the car was not classed in Street Touring category for this years Nationals, which was held last month in Lincoln, Nebraska.
Left: We saw seven FT86 cars at Nationals in CStock and RTR. Right: Our ESP Mustang did all right with 4 months of ESP development
I went to the SCCA Town Hall Meeting and it was said there that the FT86 twins would be classed in Street Touring soon after Nationals. It was inferred to me personally that the twins would go to STR, racing against the S2000, 3rd gen MX5, and the other roadsters in that class. I felt this was a bad idea and that it belonged in a slower class, STX, which is made up of heavier 4 seat cars like the FT86 chassis. Behind the scenes the SEB and STAC (the two groups that class cars in ST) were split down the middle, and I "read the tea leaves" as they would be conservative and put this car in the faster class.
There's two things you don't find in Nebraska: good Mexican food and predictable weather
I made predictions soon after Nationals that the twins would go to STR, but was thankfully wrong, as this October 2012 FasTrack notification a couple of weeks ago placed the BRZ and FR-S into STX class. There are very few preparation differences between STR and STX classes, with X having a 265mm tire width maximum and R being 255, but both are limited to a maximum of a 9" wide wheel. The rest of the rules are identical - header-back exhaust, high flow cat, cold air intake is somewhat unrestricted, outer fender contours cannot be changed, but suspension has lots of allowances. You can't use metal bushings or move pick-up points (avoid those silly "anti-lift kits"!) but you can use coilovers, camber plates, poly/plastic bushings, and more. Great classing choice b the SEB and STAC, and I commend both on their choice and apologize for ever doubting their wisdom. ;)
These are your typical STR (S2000, left) and STX (325 & 328 E36, right) front running car models
I made some statements on roadraceautox forum (aka: The Sandbox) that, if I was wrong about these cars going to STR, I would eat crow, dance a jig and prep Matt's car for STX. Ran out of time today and didn't get to take a video of me "dancing a jig" but we will do it this weekend at the NASA event. I have never been happier to be wrong, too. The SEB still has a 12 month window to change their mind when they first class a car, so if the FR-S or BRZ proves to be dominant in STX they said that they will move it to STR, potentially before the 2013 Solo Nationals. So if you prep your car for STX just... be careful not to go TOO fast at a National Tour or ProSolo. :P
This STX classing for the twin has already made a big impact on racers - just today a long-time SCCA Solo racer called me and said "As soon as I saw the STX classing I bought a car that week!" Again, I don't feel the FT86 twins will be a threat to STX, but they should at least be competitive here, unlike in STR, where they would have been cannon fodder.
Whiteline FT86 Parts Going On
We at Vorshlag were already an Energy Suspension and Powerflex bushing dealer but picked up Whiteline products last month also. This was because they had some new bushings, Watts Link, control arms and relocation brackets for our twin 2011 & 2013 Mustang GTs that we needed. We put them to the test at the Solo Nationals and Global Time Attack events last month and did very well at both. When one of their reps came to our shop before the GTA event he saw that we had a BRZ project and offered up some new goodies to test straight away. The early FT86 items from Whiteline available right away were two of the WRX/STi holdover parts that made it to the FT86 unaltered.
The first thing we installed was the Whiteline rear crossmember bushing insert kit, part number KDT922, shown above. We have these ready to sell, of course. This kit has a Polyurethane shifter bushing insert to fill a massive void in the OEM transmission bushing. Installing this bushing took minutes from underneath and it really tightened up the shift feel, but added a tiny bit of NVH in the process (noise/vibration/harshness).
You can see the gap in the OEM bushing above left and the Whiteline insert installed above, right. The main bolt from the bottom secures the insert in place. Very easy install and very worthwhile for anyone wanting a better shift feel or anyone doing competition events where this is allowed. Matt says it has a little extra vibration at 750-800 rpm and a little more engine noise at 2500-3500 rpm. It isn't too harsh, and I barely noticed it myself, but just wanted to warn anyone. He says it has become less noticeable since he has been driving it for the past week.
Next up was the a Whiteline polyurethane rear crossmember bushing insert kit, part number KDT922. We also have this ready to sell in our FT86 model section. This kit has two-piece polyurethane inserts for the rear crossmember bushings, which are made of rubber and also have BIG voids in them to make it all squishy and sloppy. Again, the OEM has to make these cars 100% smooth for every single type of driver on the road, but enthusiasts and competitors are going to want firmer bushings in several places.
Left: Stock bushing installed. Right: Whiteline KDTXXX kit installed
This rear crossmember insert kit prevents the rear differential housing from having to "wind up" against those big, open rubber bushings. They are easy to install (and easy to remove later, if the car gets sold) and tighten up the reaction time from when you mash the throttle to the car accelerating forward. Once the car was in the air the rear subframe was lowered an inch or so and these inserts were bolted above and below the rubber bushings, removing the gap and firming them up. Took about 45 minutes.
Here is a animated GIF showing the installation of the KDT922 kit
Swift Lowering Springs, Test 1
Left: OEM ride height reality. 15" from fender lip to center of wheel, F&R. Right: Photoshopped ride height goal, about 1.5" lower?
One of the most visually irritating things about this car, after we replaced the OEM skinny wheels and tires, was the tall stance. Again - Subaru and Toyota had to make the FT86 twins work on almost any sort of road or weather condition (think: heavy snow drifts), so they made it sit up tall and have relatively soft springs. We measured Matt's BRZ at 15" from center of wheel to fender lip on all 4 corners. Measuring this way will not change with tire height changes, so its how we measure all cars that have unaltered fender lips.
One of the first and most popular suspension upgrades on many sports cars is a change to "aftermarket lowering springs". These usually lower a car 1 to 1.5" and stiffen up the rates 0-20%. There are several brands and options for the FT86 we carry Eibach and Swift available for several cars. Most lowering springs have a variable rate design, where the first inch or so of travel is OEM soft but then the coil spacing changes and they get stiffer after that amount of movement.
Left: OEM rear spring next to Swift Lowering Spring. Right: OEM rear shock and Swift spring
Swift heard about our BRZ build and sent us a prototype set of lowering springs for the FT86. Well, it was more like we begged them to send us their first set (after they had done their in-house testing on them) so we could at least show something going on with this car (because our coilover shocks are very late). They warned us that this set of Swifts was not the final production version and that the ride heights were not what they targeted, so I'm not giving any stats or impressions on these just yet. We were just happy to get the first test set on Matt's car, and will revisit this when the revised production kit is built.
Left: Front Swift spring on OEM strut. Right: Rear OEM shock and Swift spring
The ride height is a bit lower but it is not dramatic, and I suspect that the production kit will be closer to 1" - 1.5" below the stock 15" number. We raised the front a tick with our prototype camber plate + OEM perch solution, which I will explain below.
Vorshlag Camber Plates for OEM Spring Prototypes
We have already been selling camber plates for the FT86 for a few months, but so far we only support the coilover offerings that use a 2.25", 60mm, or 2.5" ID coilover springs. This is because our Vorshlag camber plates always come with a new upper spring perch with an integral sealed radial bearing inside - it is a long story, but this is why our plates don't wear out or make noise or have funky steering feedback. Whenever we make a new camber plate design it gets the coilover perch first, then we tackle the OEM perch second. The FT86 uses many Subaru GD chassis parts and our high caster Vorshlag camber plates work perfectly on this car. But the Impreza GD's front OEM spring diameter is very different than the FT86's spring diameter, so we had to make something custom.
Making the OEM perch for our camber plates is a lot more involved than just fitting it to the factory diameter spring (which aftermarket lowering springs all match). To do it correctly it requires a lot of calculations, modeling and some testing to get the final camber plate + perch assembly to match the factory ride height. What we don't want to ever do is raise or lower the ride height in the new camber plate + perch assembly for an OEM/aftermarket lowering spring application. For a coilover car we actually try to minimize the stack-up height, to increase total stroke; ride height can be adjusted with the adjustable spring perches inherent to coilovers.
We took Matt's car apart a couple of weeks ago and measured the factory spring diameter and modeled the OEM top mount and upper perch but have not had time to do the full 3D design work necessary to make an all new upper perch explicitly for this chassis/spring. But we had just finished all of this design work + prototypes + testing phase for the BMW 1M OEM perch and had an extra pair of early 1M prototypes sitting on the build table when the BRZ Swift lowering springs arrived. Lo and behold, they were almost perfect fit to the FT86 front spring diameter!
So when we did the Swift spring install on Matt's car we machined a custom set of BRZ upper perches in the lathe from a 1M prototype set and - viola! - we had our first BRZ OEM spring perch solution. After installing them it looks like it needs a little more tweaking to be the perfect solution for the FT86, but for now it allowed Matt's BRZ to get up to -3.0° of negative camber in the front! His BRZ started out with -0.2 to -0.4° on the front end (and we verified this OEM camber setting range on a friend's FR-S also) so that is a big gain, and it can go right back to the stock setting (and a little beyond) for a big range of adjustment.
Here's how it sits with our prototype camber plate + OEM perch and prototype Swifts
Again, please ignore the ride height of this car in the picture above. This has both prototype Swift springs and prototype Vorshlag plates with OEM perches. Both designs are not quite 100% yet - we still need to tweak the front OEM style Vorshlag perches a bit, and the lowering springs are not production lengths either. The raised front relative to the rear is from our camber plate, not the Swift springs, too. We will readdress this in a future post when both production parts are ready. Should be a matter of weeks. These Vorshlag OEM style upper perch + Camber Plates are not for sale at this time; we are only supporting coilover spring diameters for our FT86 plates right now.
Issues With The Car
Matt's BRZ has logged a tick over three thousands miles on the odometer now, and two small issues have cropped up. First thing we noticed visually was the right rear taillight housing is showing water inside. This is likely from a crack in the foam rubber seal between the outer lens and the tailing housing itself, and condensation has entered. My brand new Mazda RX8 did this when it was about the same age (2 months old). Matt will have the Subaru dealer replace the leaking housing under warranty.
We over-filled the blinker fluid!
The second issue is the 3rd gear synchronizer seems to be shot, and it hasn't been abused. This started happening weeks before the Whiteline trans bushing insert was installed, which had nothing to do with the synchro failure. I drove the car when it was a week old and it shifted smoothly into each gear, with fast or slow gear changes. Matt has only been daily driving this car to work and on a couple of trips, he doesn't speed shift or drive like a maniac, and almost every car he has ever owned was a manual. I don't think it is user error. But today when I drove it with 3000 miles the synchro is snicking badly unless you shift 2-3 like a grandma. It takes a "1....2....3..." count to get it onto 3rd without crashing. Again, I just saw this first hand and was shocked. This will be another thing to mention to the dealer for repair under warranty.
Not trying to spook anyone - these are not necessarily unexpected issues with a brand new design like this. And also I had a then brand new model 2005 RX8 showing more issues than this - a blown strut, end link fell apart, taillight housing was full of water, and it got horrible gas mileage - so just be ready if these issues pop up. We are seeing a sample set of one here, so these two problems do not necessarily mean this is a trend.
We have more production FT86 Whiteline parts coming right after the SEMA show next month, hopefully. We have a three track events at Eagles Canyon Raceway coming up int he next 6 weeks (NASA Oct 6-7, SCCA PDX Oct 13-14, Five Star Ford Open Track day Nov 17) but Matt is out of town for two of those. Hopefully we can get it on ECR (our main test track here in town) at the November event and get some baseline test laps in.
|02 Jan 2013 07:42 PM
Project Update for December 28th, 2012: Well, we made it past the Mayan Apocalypse so I guess I can finally post up the work we've been up to for the past three months on various Subaru BRZ and Scion FR-S cars. We have done a bit with Matt's BRZ, drove it at two track days, installed various Whiteline parts and springs into multiple FT86s, and more. I worked on this update for two solid days, so it got pretty long. Let's get started. :)
BRZ Baseline Dyno Testing
Vorshlag isn't a "engine tuner" shop in any shape or fashion - we don't own a chassis dyno and likely never will. The only things we do to add horsepower are custom fabricated exhaust systems and LS1 V8 swaps, but we don't do any on-site engine building or tuning. So to do any power testing, we have to go to a few local shops that have chassis dynos. Back in mid-October, we took three of our shop cars to a local speed shop we use for tuning our Mustangs (True Street Motorsports) and got 2-3 baseline chassis dyno pulls on each. The BRZ was one of these cars, as was our brand new and bone stock 2013 GT (378 whp) and our headers/cold air equipped 2011 GT (424 whp).
Not only do we have dyno pulls done on our cars to see baseline stock numbers we are starting with, we do it after each power upgrade to verify results as well as sort of "regular engine health check-up". Kind of like an annual physical at your doctor, an annual dyno pull is a good test to make sure all systems are performing how they should. If you see big changes from the same tune/set of parts, it is worth investigating. You do this not only by looking at the peak dyno numbers but also checking the shape of the torque and hp curves (looking for irregular humps, drops or spikes) and also checking the air:fuel ratio (any decent shop that has a dyno will have a wide band O2 sensor reading as well).
Everything looked fine on all three cars and the baseline numbers on the BRZ were right about what we figured they would be. We have one dyno chart showing all 3 cars, and you can see the BRZ plot way down at the bottom. Hey, it is not a horsepower killer!
So there it is - the 167 whp BRZ monster dyno pull. This will be the baseline for hopefully some power improvements. Looking at the shape of the curve told us how the motor pulled through the rev range, with most of the power concentrated from 5000-7000 rpm. With the 6-spd gearbox, the ratios are pretty tight, which meant we knew that shifting at 7000 rpm was probably best, as the power fell off a cliff above 7K. When I was at a track day instructing with someone in an FT86 recently, who was shifting every gear on every lap at the 7500 rpm redline, you could feel the engine power falling off hard at the higher revs. I told him about the shape of the dyno curve above and asked him to shift at 7000 rpm instead. Lap times immediately dropped a full second and engine wear went down considerably (friction goes up with RPM nearly exponentially). Knowledge is power... in this case, literally.
From research done by looking at results from tuner shops, most bolt-on mods that add power to other cars are not showing significant gains on these FT86 cars. We have seen beautifully made, custom mandrel bent exhausts lose power on an FT86. Cold air kits that make the engines run poorly. It all boils down to the ability to add a custom tune - which is proving elusive to the various tuner shops, for now. Once the Toyota/Subaru engine management code is cracked, there could be potential gains to be had. For now we recommend concentrating on handling - tires, brakes and suspension - where we have seen SIGNIFICANT improvements with the right choice of parts.
Wheel & Tire Improvements - EVEN BIGGER!
Obviously we have been big supporters of ditching the factory FT86 17x7" wheel and 215mm all-weather Prius tires. The stock rubber is so very, very bad for performance, the OEM wheels are somewhat heavy, and all of it is too narrow for this 71" wide car (that is WIDE!). We've been preaching the evils of the factory rubber since before the car came out, and I got a lot of flak for the negative review of these skinny stock tires. But we didn't back down, and our theories proved correct - these cars respond immediately to wider tire and wheel upgrades with big grip increases.
A decent wheel and tire upgrade makes huge, HUGE gains in lateral grip on this chassis. Early on we went to a light-ish 17x9" alloy wheel on Matt's BRZ and have used two different performance street tires on them now. First was the 245/40/17 Michelin Pilot Super Sports on the 17x9" wheels, shown below. These tires fit these ET42 offset 17x9" wheels with just a little extra camber up front. No fender rolling or spacers were needed. Excellent street tire, quiet and grippy, and could even double as a good autocross or track tire.
Left: The 245/40/17 Michelin on the 17x9" wheel dwarfs the stock 215mm tire on the 17x7" wheel. Right: 245s installed.
Before his first track event, Matt decided to upgrade to some more track proven EPS (Extreme Performance Summer) tires, the Hankook R-S3, in a slightly wider 255/40/17 size. We ordered these through our TireRack account, then mounted and balanced them here at Vorshlag on the same wheels.
These 255 tires are big and actually fit the 17x9" wheels a bit better, but proved tricky fitting on the front of the car. The 10mm wider tire was touching the lower spring perch, with the large diameter OEM style springs. Just touching, but that's enough to necessitate a spacer.
We had to slip in a 5mm spacer up front to clear the strut, but o make that work we had to add longer wheel studs to the front hubs. You can read about that process below (luckily we stock and sell 65mm press in Subaru studs!). Ain't it fun modding cars? Sometimes it can snowball... one change (tires) can sometimes involve two more (spacers and wheel studs), but the results can sometimes be worth it (crazy grip!). The 5mm spacer proved to be the perfect amount of tire to strut clearance needed up front, with no rubbing on the strut or front fenders (with additional negative camber). The rear bolted on with no adjustments - we could easily get a 9.5" if not a 10" wide wheel out back (but why?).
Notice how we did NOT go to 18" wheels on the BRZ for his track tire? This was no accident. The FT86 chassis is light and nimble, and the stock brake rotors are relatively small in diameter. The only performance reason to increase wheel diameter is to clear larger rotor sizes, period. Everything else is done for STYLE. Big ballin' wheels look cool and cool cars are fast - or that's at least what we've been taught. If you can turn off that instinct and go with what is actually better for handling, you will stay with 17" wheels on these cars. As you can see below, even with +30mm more tire width (that is huge!) and +1" of wheel width, the 17x9" combo is very similar in weight to the 18x8" combo shown (and this 17" wheel isn't particularly light).
Compare the weights of a somewhat heavy 18x8" wheel and 225mm tire to a light-ish 17x9" wheel and 255mm tire.
Technically the FT86 could even use 16" wheels and still clear the stock brakes with ease, but then your tire choices shrink to almost nothing. This stems from a problem of tire size availability in smaller diameters. The tire manufacturers have catered their offerings to the car manufacturers' ever larger wheel diameter fascination, and now to get any decent widths in performance tires you have to go to 17". Well 17" diameter tires tend to top out at 255mm (some 17" tires go to 265mm) width, so if you want wider you have to go up to 18". Each step up in wheel diameter shortens the sidewall height (bad for ride and handling), ups the weight (bad), and ups the cost (bad). It just becomes a whole big bag of bad, so if you are chasing ever wider tires you end up in 18" wheels - but on big heavy cars you have to do that. We feel that the 255mm tire fits the lighter weight and overall performance of this car very nicely, so 17" wheels will work the best. For a street-only "fun" set of wheels... sure, go crazy 18", but just know that it will be heavier, ride worse, and tires will cost more than a similar 17" wheel set-up would.
This BRZ on the 17x9" wheels and 255/40/17 R-S3 Hankook tires is 71" wide, and the big track width is great.
Better Brakes for the BRZ?
Matt's car has also had some brake system upgrades to get it ready for the track. We left the rotors and calipers alone, because we wanted to see how well the car could do on track with just upgraded pads, lines and fluid. And the results are that it does VERY well with those upgrades alone. Incredible braking performance, no noticeable fade, and no need for more brake torque. So a "Big Brake Kit" (BBK) upgrade is not on the short list for mods, or even the long term wish list, until the car gains a lot more horsepower.
We took a gamble and went with a pad brand that several racers recommended - Carbotech. The XP12 compound were used up front and XP8 in the rear. This seemed like the best "track pad" for the size brakes the car had, according to Carbotech. And they were right - it was spot on perfect. They did recommend the XP10 compound for the front as well, but it wasn't available in time for the first event. Sure, they dust and make lots of noise, but we didn't want a compromised dual-purpose pad. These are used for track events only and after tracking with them twice, we think they were the right choice (and they still look great!). We swap back to the OEM pads and rotors for street and autocross use, which are quiet, work better cold and make a lot less dust.
While the pads were going in, we had custom stainless braided Teflon lined brake flex lines built to order. These are made by a friend of ours using high quality BrakeQuip brand parts, and all ends are crimped on a DOT numbered machine, for the best possible quality and street legality. We made them exactly like the OEM brake lines, with all of the goofy Subaru style banjos and FT86 specific ends and brackets, unlike the lower cost brake line kits we've seen popping up for the "FT86" chassis. Most of those are somewhat generic Subaru WRX kits, with many of the brackets missing and none of the locating tabs.
This makes our Vorshlag FT86 brake line kit cost nearly fifty or more dollars than the other braided brake hose kits out there, but our lines actually fit the FT86 exactly like the original Subaru lines. The lines attach to the struts just like the stock ones, and aren't held in place with a zip-tie. The ends are clocked properly and point in the right directions, for a kink-free installation. Our motto is Do It Right The First Time. The details are too numerous to go over here - check out the product page linked here to see the differences in our lines vs cheaper ones. Our kit will never be the cheapest out there, not by a long shot. Making the lines to fit and function exactly like stock lines is harder and costs more. These are DOT approved stainless braided lines, so they don't have the expansion/flex of the stock rubber lines. Better brake feel and the utmost in safety.
We also flushed the old factory brake fluid out and went with a full bleed using Motul RBF600. The much higher boiling point of the Motul brake fluid means less chance of boiling on track and going all to mush. We didn't do this on my 2013 GT for the October NASA event and I lost the pedal about halfway through my first sessions and drove right off the track! Huge mistake - never skimp on proper brake fluid for any car you take on track. At the bare minimum the brake fluid should be replaced with high quality, high boiling point DOT4 fluid.
Does the car need brake ducting? Surprisingly it didn't. After I took several hot laps in the car, abusing the brakes like I tend to do, Matt's BRZ with these pads/lines/fluid made lap after lap topping 1.4-1.5g under braking. Hey, at least that's what the AIM Solo data shows, and we were out-braking all sorts of cars. I was amazed that I couldn't overheat the brakes, but maybe I could on a hot Texas day taking a full 20 minute session of abuse. I could overheat the 255mm tires before the brakes would fade, so who knows? If we see the brakes fading with more suspension mods and lower lap times, we will come back and look at adding brake ducting to the front. But for now it seemed fine without it - a rare thing in modern sports cars.
|02 Jan 2013 07:47 PM
(continued from above)
Other FT86 Track & Autocross Preparation Work
We have worked on a number of local FT86 owner's cars, getting them ready for track and/or autocross use. Britney's FR-S was already modded with a custom exhaust and some aftermarket 17x7" wheels and 215mm Hankook R-S3 tires when it came to Vorshlag for some front camber help.
Looking at other Subaru modders online, they went with the smaller shank diameter Subaru "crash bolts" at the upper front strut to spindle bolt location. Normally the FT86 (similar to the Impreza which the suspension is based off of) has the "enlarged shank" 16mm bolt in the upper spindle mount holes and the 14mm bolt in the lower holes. This "crash mod" entails swapping out the fatter upper spindle bolt with the slimmer 14mm bolts, so now there is slop in the mounting holes and you can tweak the strut inboard a bit more without slotting any holes. It... is not the ideal way to gain camber, but it is a simple and inexpensive way to gain about a degree.
So Britney's FR-S and it had -.2° and -.4° deg camber up front from the factory. We spent a whopping 30 minutes installing these bolts and got the front camber to -1.7° on both sides. Not bad for the stock ride height, and anything is better than the stock setting for track use. Personally I like to see -2.5° or more for track but hey, for as cheap as these bolts are it isn't half bad.
Next up was Mark's FR-S, which got the first production Swift lowering springs we've installed as well as Whiteline's front and rear camber kits. The front kit is similar to the crash bolt fix, but uses nicer bolts and other specific hardware (see below for further details). The rear kit includes a pair of offset and adjustable elastomer bushings for the upper control arms. Mark already had some 18x8" ET48 "Sparco" wheels, which were pretty and at least an inch wider than stock. However, since the costs were low and they were 18" diameter, they were also fairly heavy. Still, almost anything is an upgrade over the skinny stock 17x7" wheels. For tires he had 225/40/18 Michelin PS2s.
We started by checking his ride height, toe and camber settings at all four corners.
Before and after ride height checks shown on the RF corner (from 14.5" down to 13.5").
Then we pulled his OEM springs and rated them on our digital spring rater. And we rated Matt's OEM BRZ springs as well. Yes, they are indeed different...
Here are the FR-S and BRZ OEM spring rate charts. Kind of big, but they need to be to be legible.
FR-S and BRZ OEM spring rates, as tested by Vorshlag. Click above to enlarge.
As you can see, the stock FR-S rates are pretty soft, but fairly linear both front and rear. The BRZ's OEM springs are stiffer up front (+63 lbs/in) and softer in the rear (-20 lbs/in). In the grand scheme of things that isn't a lot of stiffness, but the balance difference is probably noticeable if you drive the two cars in stock form back to back on track. But who wants to keep these soft stock rates and 4x4 ride heights? Most of you reading this won't.
After rating Mark's FR-S springs, we installed the Swift BRZ lowering springs, p/n 4F912, which we also tested for rate.
Click the Swift spring rate chart above to enlarge.
The overall drop when we installed these Swift springs onto Mark's FR-S was almost exactly 1" at all four corners. We shortened the bump stops as well. We took about 1/3rd of the OEM bump stop off from each corner.
Once the springs were installed, it was onto the Whiteline rear UCA bushings. These were tricky to install, mostly due to the hassle of cutting apart one of the OEM bushings to be able to press it out of the control arm. We figured out some tricks and with our bushing installation rig we were able to get the old ones out and the new Whiteline bushings installed. Kind of a mess, but once the "flange" was cut off the OEM rubber bushings they could be pressed out. This is a job probably best left to "advanced" modders or your local suspension shop.
Now the rear camber can finally be adjusted (which the stock rear suspension is otherwise lacking) and a pair of OEM rubber bushings are gone, so this point will no longer deform under heavy lateral loading (track/autocross use). We like this kit and will be picking up a set for Matt's BRZ as well as some sets to stock and sell.
Whiteline's eccentric camber bolt kit as installed on the front strut of an FT86 @ Vorshlag.
Last up was the installation of the front camber adjustment bolts. Unlike the smaller diameter Subaru crash bolts we installed on Britney's FR-S, Mark went with the eccentric camber bolts from Whiteline. Again, these replaced the big 16mm shank upper strut mount bolts on the front struts and also allow the struts to be tweaked relative to the spindle, for some slight camber adjustment. Again, about a 1 degree change is normal. We sell this kit here at Vorshlag, as well as all of the Whiteline parts for the FT86. This is another cheap and easy way to get some camber adjustment in the fronts of these cars. But ... just like with slotted strut mounting holes, there are downsides.
First, given enough lateral force on the strut mount, the smaller diameter or eccentric bolts could slip, which would knock your camber out of alignment on one corner. This could happen from tapping a curb or heavy pothole, or even aggressive track driving with high enough grip tires. This didn't happen on Britney's FR-S on 215mm RS-3 tires, even with crazy KenO driving it, so that was a good test. Mark's car seems to be holding up with these eccentric bolts as well.
Next, any time you tweak the strut angle relative to the spindle you are removing wheel and tire room inboard at the strut. Now this doesn't pose a problem unless you are pushing the envelope on wheel/tire room inboard - on Matt's car with the 255mm tires, it was a big deal. Even without any strut mounting tweaks the 245's barely fit inboard, and the wider 255mm tires needed a 5mm spacer. If we had done crash bolts instead of camber plates, both situations would have needed to move the wheel outboard more, with more spacer thickness. There is no free lunch - every modification always has pros and cons. Just keep that in mind when using crash bolts or slotted strut mounting holes to gain negative camber. For street use on normal street tires of normal widths it isn't an issue. And keep an eye on your camber; if it slips, get the car re-aligned.
Left: Before with the OEM springs. Right: After the Swift spring and Whiteline bushing installation.
Mark's finished FR-S now sits 1" lower, rides better, and should handle better with a bit more spring rate. The camber is adjustable both front and rear and the rear UCA has Whiteline elastomer bushings. The added negative camber up front will help handling at the limit and save tire wear on the track. I'm still not a huge fan of camber bolts, but on certain set-ups and street tires, they can work. And honestly we sell camber plates, so crash bolts are never going to be high on my list of approved mods. ;)
2013 Scion FR-S on Swift lowering springs + Sparco 18x8 ET48 wheels.
Mark also has our Subaru M12-1.25 long wheel studs installed on the rear hubs of his FR-S. He uses the longer studs to work with a 10mm hub-centric spacer he needed to make the +48 offset 18x8" Sparco wheels sit with a wider rear track out back. He said it fit without the spacer, it just didn't fill out the fender very well.
Mark said the rear studs were easy to install once he figured out how to remove the rear hub assembly (see above left). Off comes the half shaft retaining nut, then you unbolt the hub assembly from the emergency brake bits and you can remove the rear hub. Once removed from the car, you can use a press to push out the rear studs; the new studs go in the same way. With the Vorshlag 65mm studs installed out back, now there is full engagement of the threads on the longer/larger Vorshlag lug nuts even with that 10mm spacer installed (see above, right).
Our 65mm Subaru style Vorshlag wheel studs install into either the front or rear hubs relatively easily. As you can see the installed length is 48mm past the hub face up front, compared to only 25mm of stud protruding with the stock wheel studs. This upgrade gives you a solid 23 mm increase in stud length over stock, but they don't look silly or stick out excessively with the Vorshlag lug nuts. A solid upgrade for any track or autocross car - more lug nut engagement and the ability to run up to a 20mm thick spacer, if needed.
We installed these on the front hubs of Matt's BRZ when he upgraded to 255/40/17 Hankook R-S3 tires. The front wheels needed a 5mm spacer to allow this fat tire to clear the struts. Any spacer use requires longer wheel studs, as the stock studs are very short. This also necessitates new lug nuts since the stock nuts are very short, close ended lug nuts.
For those extra picky folks worried about long wheel studs making their FT86 look like Roman chariot wheel spikes, or the modern equivalent, fear not. As you can see above on the BRZ with our "65mm wheels studs" and a 5mm spacer there isn't a hideous amount of stud protruding past the lug nuts. This is just how a race tech inspector wants to see - full lug nut engagement, plus a little more. Perfect.
|02 Jan 2013 07:48 PM
(continued from above)
We got a call from someone that writes for Grassroots Motorsports asking for a pictures of an FT86. They were looking for some action shots with typical autocross classing/sponsor stickers shown mid-corner or in a slalom. They had a tight deadline and nobody had any pictures of an STX prepped FR-S or BRZ they could find. We love working with magazines and especially the folks at GRM, so we made it happen.
Olof washed and detailed Matt's car, Jason cut some class/number/sponsor decals, and Olof and I slapped on the numbers and some GRM decals. I asked Jason to make the numbers big, but dang - you can see these from space! :P Then we went in search for a parking lot that would work for the photo shoot. Once there, we set up a slalom and Brandon got his camera gear ready. I got in, strapped on a helmet, and hooned around the cones - while keeping an eye out for the law. This was an unsanctioned operation...
The parking lot we picked was a local movie theater across the highway from Vorshlag, and by a large helping of dumb luck we just happened to see my 2013 Mustang GT parked in the same portion of the giant parking lot. Apparently my wife had snuck off to watch some sparkly vampire movie - on a vacation day she took from work that she "needed" in order to get ready for a Thanksgiving party we were throwing the next day. Sneaky. What she didn't know was that I had an extra key to this car... so we moved it to another lot about a half mile away and I waited for her panicked call. :)
It didn't take long - half an hour later I got the call, "The Mustang is stolen! Either that... or.... YOU took it!" She knows me too well. I told her where the car was parked and she hung up on me. Later that day she admitted it was a good practical joke, heh. We laughed about it for days!
The photos came out well and you should see one of the above shots in an upcoming GRM issue.
Two FT86 Track Tests @ ECR
At the end of my October post we had three track days in the works for October and November. Matt was out of town for the NASA event, where we ran two of the other Vorshlag shop cars and set some new personal best lap times (in our 2011 and and 2013 Mustang GTs). Then the SCCA Club Race/PDX event was cancelled (they had all of 37 people sign up...and we were 3 of those. Club racing in our region is virtually dead), but the Five Star Ford track day event was the first one where we had some FT86 content.
Vorshlag Picture Gallery - 5 Star Ford ECR Track Day - http://vorshlag.smugmug.com/Racing-Events/Five-Star-ECR-111712/
This November 17th event was an HPDE hosted by Five Star Ford of Plano at Eagles Canyon Raceway. We had fun at their event back in June so we signed up three more cars for their November 17th event. Amy drove the red Vorshlag 2011 Mustang GT to her new personal best at this track (1:57.70!) and Matt drove his 2013 Subaru BRZ (2:11.0). I was there for track-side help and in-car instruction, Ed was there to help with the three cars, and Vorshlag's photographer Brandon was on hand and took some great track pictures of many of the cars in attendance. Perfect weather, well run event, and we had about 63 cars in attendance, so we got a LOT of track time. Big thanks to Corey White for setting this event up!
Left: Matt's BRZ on course. Right: Britney and her FR-S.
Being a Ford dealership sponsored event there were a crap ton of Mustangs in attendance, and I will go into more of that in our next
We were back at ECR once again a few weeks later, on December 8th, and Matt again brought his BRZ with zero changes from the November event. It was a much colder day and lap times were a solid 1-1.5 seconds off our times at the Ford event, when the weather was a bit more favorable. This time Matt took a lot more laps and got more acquainted with his car. I was busy driving my 2013 GT with new AST double adjustable shocks and Vorshlag camber plates, and Amy was in her 2011 GT again. Also, two of my buddies and I were doing our first track laps in our future ChumpCar, so it was a very busy day. It was so busy, in fact, that nobody got any pictures of Matt's BRZ on track! Doh. It looked so purdy with all of the decals... oh well.
He did get a little in-car video with his new GoPro Hero3. Not the best audio, but you can get some idea of what this car looks like on track.
For NASA TTD competition (the NASA class we are building it for), it needs to run closer to a 2:05, but with coilovers and some other tweaks we think that is doable on these R-S3's. For SCCA we're building it around STX class, which allows up to a 265mm tires. I don't think that will fit as it sits, but with their poorly written rules concerning fender contours and lip rolling, "anything is possible". :)
Coilovers are the next obvious modification, but we don't have anything to install yet - still waiting on his AST 4150's. For now we will go ahead and install the production Swift lowering springs and confirm the data we have seen on Mark's car (1" drop, great ride). There are some additional Whiteline FT86 bushings that have made it to market (rear UCA bushings) and more are promised in late January - as are their adjustable FT86 sway bars. No power mods will be done until there is a proper tuning solution, so 167 whp is where it will stay for a while.
We don't have any autocross or track events until February, but if we get in some parts before then we'll post up again. Sorry for the long update today, bu we had almost three months to cover. I will try to be more prompt in my updates in the future.
Terry Fair @ Vorshlag Motorsports
|20 Aug 2013 06:26 PM
Project Update for August 20, 2013: It looks like we had a huge delay since our last project build thread update on the BRZ Project; it hasn't been discussed since December of 2012. There were some lengthy delays waiting on shocks that were a bit out of our control, which we will explain below. We also got very busy with other projects and racing in other cars. But in the past few months a lot has happened behind the scenes with our in-house 2013 BRZ and we've finally installed proper monotube adjustable coilovers that actually fit these cars at lowered ride heights. We put these to good use at an autocross recently with surprisingly good results. Read more below...
What a difference a year makes! Left is bone stock, right is last week on MCS TT1 shocks, 17x9" Enkei RPF1's and 255 BFG Rivals.
One more thing. Starting in early 2013, all of the pictures in my forum posts can be clicked for higher resolution versions, unless they are posted in-line with BIG format pictures. This takes more time and makes the character count of my posts longer, but we feel it is worth the extra effort to split up posts into multiple sections. With a professional photographer on staff, we WANT you to see our images in higher detail. As always, these watermarked pictures are all copyrighted by Vorshlag, so we ask other shops NOT to steal them (yes, it happens). Anyway, if you see something you like, click that pic!
Where Were We? Waiting On Coilovers...
At the end of my last post (What's Next?) in December we had mapped out future suspension mods. Coilovers were the obvious next modification slated, but that didn't quite pan out as we had expected. There were some early coilover shock options for the FT86, most of which were straight off of the Subaru Impreza that this FT86 chassis was loosely based on. But as we saw, many of those early kits were compromised in some way - namely in the fact that the front struts were not utilizing the room under the spindle for extra travel. Unlike the AWD Impreza, the RWD-only FT86 has several extra inches that could be exploited up front for more strut travel, using the area that the AWD Impreza front half shafts would have been. None of the rushed-to-market coilover solutions used that room. The rest of the kits we saw were all twin tube shocks, which we are not fans of.
This picture was made for a photo shoot last year with stock shocks/springs/sway bars. Handling was pretty awful.
Without proper coilovers to install we weren't about to try to autocross or track this car seriously, either. Sure, the production Swift lowering springs arrived and they looked good, but with the stock length struts and shocks there just wasn't a ton of compression travel to be had. And no lowering spring is going to be significantly stiffer than the OEM bits, not enough to matter for performance handling. Sorry, that's just the truth. Lowering springs are 90% for looks and 10% help handling by lowering the CG. When we see folks arguing one brand of lowering spring over another regarding performance, or one model of OEM spring vs another (BRZ vs FR-S), we have to bite our tongues... because we know it is completely pointless internet talk.
Real coilovers geared towards competition use can work with substantial increases in spring rates. Not 0-30% stiffer, like most lowering springs add, but 100-500% stiffer spring rates. Spring rate changes like this cuts way down on chassis roll/heave/dive, and that's where we've seen the biggest gains over the years with suspension changes - spring rate. And no, the spring rates I'm talking about do no automatically mean "bone crushing ride", not if used with proper monotube shocks. The relatively massive pistons in monotube shocks (relative to twin tube shocks, like the OEM bits) make for a massive increase in low speed sensitivity to movement, so they react more quickly to bumps than any twin tube shock ever could, no matter how stiffly valved. And the large range of adjustment in most aftermarket monotube adjustable shocks means they can work with much stiffer rates and still provide a good ride when the valving (knob) is turned down for street use. These reasons are why Vorshlag ONLY sells monotube shocks - we've seen the glaring limitations of twin tube shocks and just don't want to be a part of that "solution". Sure, Twin Tubes shocks are cheap to make and they have their share of budget-oriented fans, but they don't belong on a car that will be used in competition, and are never going to be something we recommend or sell. Yes, some folks call us shock snobs - but we have our reasons.
Nearly 8 months after we ordered the first prototypes we finally got a set of coilovers from a monotube company to test. We tested their set-up on Matt's BRZ several times over 2 days, with and without springs, and we found several issues. These included brackets that didn't fit the mating hoses, mounting holes drilled the wrong sizes, and strut and shock lengths that were completely wrong. There was no easy fix for the strut length problems, either, other than running them at stock ride heights - which we weren't about to settle for. These tests were a real set-back and we knew this would turn into another huge delay. Still, we had hope, so we spec'd out the proper front strut and rear shock lengths and waited to hear back about a new set that could actually work at a lower ride height.
More months of waiting turned up nothing. It was a problem with the supplier, who was unwilling to make any changes - even if every issue we noted was true. Nobody involved came out ahead on this one. We wasted months waiting for a fix that never came and lost a lot of time in the FT86 suspension market. Matt's BRZ was just tooling around on nice wheels, good bushings, and lowering springs - all dressed up but not race worthy. After seeing how this car fared on track with the stock shocks and soft springs, we knew it would be better suited to proper coilover spring rates and dampers, and really wanted to move to the next step.
I cannot fully put my frustration into words, but I'm not throwing any names around. I'm just going to leave it at that. So after we ran out of patience waiting we broke down and looked at other vendors making quality monotube coilovers for the FT86.
Monotube Coilover Solution Found in the MCS TT1
A relatively new shock company we've been eyeing for a while was Motion Control Suspension (aka "MCS"). This is an American company started in 2011 that has the same principles that formerly ran Moton for 12 years. We had seen that they had made their new MCS non-reservoir single adjustable monotube coilovers for the FR-S/BRZ and the SCCA C Stock guys seemed to love them. This run of FT86 coilovers were made explicitly for this class's unusual shock rules: where OEM spring must be used and the shock length can be no more than 1" different from stock.
Left: Moton 2-Way Dampers we built for SCCA Stock Class BMW 135i. Right: Custom perches for F Stock use on S197 Mustang
The MCS solution for this class was sold with adapters to convert them from adjustable height coilovers normally holding 60mm springs over to fixed height struts that worked with the OEM springs. As crazy as that sounds, we have built shocks like this with other shock companies in the past. It is a very small, niche market of a few dozen racers a year that buy shocks for SCCA Stock class. They can easily cost upwards of five thousand of dollars for custom built double adjustable, remote reservoir shocks that work within the narrow confines of the SCCA Stock classes, and they do find performance benefits in a few loopholes... but nothing like a set of proper coilover springs would give them if they weren't saddled with that class' oddball shock/spring rules.
We loved the quality and durability we've seen in Motons, and I run Moton Doubles with remotes on my personal NASA-TT3 Mustang. But while Moton never offered a single adjustable shock, the folks at MCS did, releasing their non-remote single adjustables in early 2013. A Single adjustable non-remote reservoir monotube coilover is one of the areas we at Vorshlag really excel in. This type of shock has a big chunk of the performance benefits of a 2 or 3-way remote reservoir monotube (that can costs $4500-8000+) but at about half the cost of "remote doubles", and without the hassles of mounting reservoirs/hoses. Monotube Singles are a great solution for 80% of the coilover users out there, and we really needed this "internal single monotube" coilover if we were going to play in the FT86 market.
Since stock springs and stock length struts and shocks aren't what 99% of the FT86 crowd wants, we saw a glimmer of hope in MCS, and wanted to give them a try. We talked to MCS, set-up Vorshlag as a dealer, and ordered one of these FT86 sets in our initial stocking order. We knew they might not be the right length but were willing to test them and see, and they said they'd be willing to customize them to our specs.
Left: MCS TT1 singles for FT86, kit priced as shown is $2750. Right: Vorshlag pinned spanner fits the ride height perches perfectly.
|20 Aug 2013 06:27 PM
continued from above
We got our first FT86 set in and they looked absolutely beautiful. We could see they already had a lot problems we saw in other brands solved. The included strut bracketry was made to fit the hoses and lines on the BRZ perfectly. They had a nice solution for the slotted holes found in many struts using precision CNC machined fixed offset insert slugs. The coilover perches were all metal (not plastic) and 2-piece, that clamped in place with spanner wrenches (not bolted) and one of the Vorshlag pinned spanners we've made for other brands of coilovers fit perfectly.
Testing the strut and shock lengths on the first set of MCS singles - almost there...
Sure enough, as the MCS folks expected, their "C Stock" length singles were too long to work at the lowered ride heights we wanted to run this BRZ at. And they should have been, as they were initially intended to be SCCA Stock class legal (it is nearly impossible to make anything legal for Stock class work at properly lowered ride heights - without some major compromise somewhere). You see, we had been looking at NASA Time Trial and SCCA STX to run in, and in those classes we could lower the ride height and use true coilover springs in any rate we wanted - a novel idea that almost any competitor would want.
That day we went through the same battery of measurement exercises with the MCS singles as we always do on any new set of shocks we test. We re-spec'ed them with our desired ride heights, then measuring bump and droop travel at the wheels, with and without springs installed. We sent along our wish list of drawings and measurements and shipped this first set of coilover shocks back to MCS, hoping they would make us a set of housings, shafts and lengths that would work.
Lo and behold, they delivered a new set built to our specs in less than 2 weeks. We were floored, as this turn-around time was much quicker than we had even hoped for. We took the 2nd set and tested these on the BRZ again, going through our full sweep of tests with and without springs once again. By now we had burned about 4 days of shock testing on this poor car over the previous few months and hadn't driven one mile on anything but the stock shocks. Luckily the third time was a charm, and the 2nd MCS set was a winner. They fit with the lowered ride heights we wanted and now offered real usable bump and rebound travel at both ends. Hot damn!
Left: New Vorshlag tender spring. Right: The MCS TT1 shock worked with the stock rear top mount, Hyperco spring & our tender.
This may seem like a trivial thing to some of your readers, but getting these MCS "TT1" shocks built correctly and onto this car, with real spring rates and usable travel in both bump and rebound directions, was a long time coming. Big thanks to Lex and the folks at MCS for getting these re-made so quickly and for working with us and our needs. So now we needed to know - how do these dampers RIDE and HANDLE?
The ride aspect was easy - let's go drive it. With the initial set of springs we went with a 450 #/in spring at both ends. If you look at the charts below of the OEM and lowering spring rates, which we measured here at Vorshlag, you will see that we nearly tripled the front rates and doubled the rear rates. That's usually a good starting point for us, and we also based the 450F/450R rates on our years of Subaru GD chassis shock sales, testing and racing. To keep the rear spring seated at full droop we added our new Vorshlag 60mm ID tender springs (shown above) on the rear shocks, too.
Left: Stock 2013 Subaru BRZ spring rates, front and rear. Middle: Stock 2013 FR-S rates. Right: Swift BRZ progressive rate lowering springs
A few drives on our 2 mile "shock test loop", a couple of rebound knob changes, and we had the ride set to "Amazing". Yes, with triple the front spring rate it was handling bumps better than the stock shocks did with lowering springs, which often bottomed out. It was firmer but not at all jarring, and we quickly knew this would be a big seller.
Note: We have renamed MCS' line of shocks with actual model names that are easier to type and remember. We began referring to the non-remote single adjustable shock as the "TT1". This refers to the fact that in many forms of Time Trial racing you get dinged points for remote reservoirs, so these non-remotes are better for that sport, hence TT. The "1" refers to the number of valving adjustments. There are TT1 and TT2 models for most MCS applications - yes, the elusive double adjustable monotube without remotes does exist. We've already sold several sets of TT2s from MCS. And the RR2 and RR3 are "Remote Reservoir" 2 or 3-ways. Get it?
Of course we used our Vorshlag camber plate solution, mated to our custom built 60mm radial bearing upper spring perches. These worked perfectly, giving the car an extra .75 degrees of positive caster over stock (by moving the strut pin backwards). The camber setting range is huge, and at this lowered height we were able to get a max reading of -3.4° camber in the front and -2.6° rear (with the stock rear arms). Our technicians corner balanced the car and the final ride heights at 13" front and rear, approximately 2 inches lower than stock. And yes, it clears the big 255/40/17 BFG Rivals with ease.
Now, when could we find a competition event to run this in?? There was a Texas Region SCCA autocross (Aug 18th, 2013) only a few days away, so Matt and I signed up...
Well this forum update has already run far too long, and I barely covered the MCS TT1 install. Sorry - it was such a long wait getting proper coilovers on this car, you have no idea. I am going to cut it short and cover the rest in another installment in about a week, before we head off to the NASA National Championship event to compete in our TT3 Mustang (we're thrashing to finish up some front aero work on that car in our shop this week) and visit with other customers there.
Left: The BRZ with MCS shocks was surprisingly fast at its first autocross. Right: MCS RR2 remote doubles being installed onto an FR-S at Vorshlag
In our next BRZ Project Thread update I will show details of another set of 17x9" wheels we tested, how a set of 255/40/17 BFG Rivals felt, cover an autocross event we ran in the BRZ with 2 drivers, and show off some MCS RR2 shocks we're installing onto a customer's BRZ track car this week. We have several more autocross and track events planned in the car this year as well.
Thanks for reading,
Terry Fair @ Vorshlag Motorsports
|31 Aug 2016 05:04 PM
Project update for August 31, 2016:
It has been 3 years since I last updated this thread. When we left off in August 2013 I had just autocrossed Matt's '13 BRZ on the newly installed set of MCS coilovers and 255mm Rivals. Matt left Vorshlag shortly after my last post, so we lost our "in-house" 86 test chassis. We have of course worked on many more 86 chassis cars since then, and have even developed some new products. I will cover all of that, plus introduce another 86 into the Vorshlag shop - my wife Amy's red 2013 FR-S (see below) which she bought a week ago.
Vorshlag 2013 FR-S which we tracked in stock form last weekend to get a "Baseline Lap Time"
We've already weighed it, fixed a number of worn or broken items, then tracked it at Motorsport Ranch to get a "baseline stock lap time", which we will use to gauge improvements over time. We bought this car to test fit "some new items" we just moved into production for this chassis, and we will also use it to develop and test more new products over the next year or two. Let's get caught up first, then cover the product developments we've made for the 86, then show our new shop car and the track test.
SCCA AUTO-X AT CRANDALL, AUGUST 18, 2013
Yes, I am doing an event write-up from 3 years ago - but it was a very memorable event for several reasons. This event happened during a hectic series of weeks, as we were developing and track testing a new aero package for our NASA TT3 classed Mustang, which we took to the NASA National Championships at Miller Motorsports Park a couple of weeks later (where the car did OK, trophied 3rd in class - we changed the aero package further soon after and made even bigger gains).
August 2013 was a hectic time at Vorshlag - working on a lot of cars & prepping for NASA Nationals
This August autocross was also the first and last time I competed in Matt's BRZ, as he turned in his notice shortly after this event (moving on to a higher paying job outside of motorsports, which we wished him well with). The local autocross clubs lost this site shortly after this event, and it was the last time I ever got to race at Crandall. Just a bunch of reasons why I lost track of time and never did this event write-up in the BRZ after adding the MCS coilovers.
Event Photo and Video Gallery:
At this August 2013 autocross, Matt ran his BRZ in Novice class with an STX pax and I ran it in the open STX class. The car at this point had a few Whiteline bushings & swaybars, MCS coilovers with the rates we have since spec'd on dozens of 86 cars, Vorshlag camber plates, and the ever popular Enkei RPF1 wheels in 17x9" with 255/40/17 BFG Rival tires (this was long before the Rival-S or RE71R arrived on the "200" treadwear autocross scene).
Right off the bat the handling felt so much better than with the stock dampers and lowering springs. This clean concrete parking lot had a busy layout, but similar to several events we had run at this now defunct site. As they typically did, this course had lots of turn-arounds, slaloms and offsets.
We made only a few damper and tire pressure adjustments and swept both the STX and Novice classes. Matt took first in novice out of 29 cars
at this, his first autocross event in the car. My entry in STX was 1st out of 4
, 13th out of 111 in PAX, and compared well to other STX and STU cars that ran that day.
There were other STX cars running in other classes, like Brad in "X" class (for pro level drivers), and Sipe who ran in SMod that day. Sipe was ahead of us but that was in an RX8 with possibly the highest STX level prep of any car in the nation at the time, and he also run in a later heat. So with a car that was just setup on MCS coilovers the BRZ was pretty dang quick, and we were happy with that.
That same day Amy and another autocrosser Mark Council both drove very well prepped Mustangs in STU class - as a test. Amy was driving our 2013 Mustang GT (on AST remote doubles, bars, brakes, 18x10" wheels, more) and Mark was in his even more prepped 2012 GT. Their two drives provided two more pieces of data to show that the pony cars didn't belong in STU class. Mark and I both raced his car in STU the month before at this same site, too.
At that August event they were both on competitive tires and drove well, but they both still brought up the bottom of the STU class and were 3.5+ seconds behind my STX time in the BRZ. Remember - STU is supposed to be faster than STX
. I've co-driven with both of these drivers many times - they are both fast, and Amy even has the National Championships to show for it. This data from this and some previous events was what we used when we wrote in for new rules allowances for the stick axle cars in Street Touring... which led to a letter writing campaign... which eventually
led to the formation of the STP class (right after CAM was introduced, terrible timing). So their drives were worth noting and comparing to the STX times of this BRZ, if you follow those classes.
In-car video of my fastest time that day
The in-car video above was my fastest autocross time of the day in the BRZ, but there were still a number of "qualifiers" from this run that I have to note. First, I had Mark Council riding with me, and he is no dainty little boy.
Second, there was a lost car randomly driving around on course, which I noted so I backed off briefly... to make sure he wasn't going to swerve in front of me (the corner workers red flagged the course, behind me). Lastly, STX ran in an earlier session that day and the course had about a dozen spots of water seeping up through the concrete (from a recent rain) that slowed us down a tick. The course dried out in later sessions and those drivers were generally faster. So the car could have been even quicker without these issues.
I remember that autocross vividly. The BRZ handled so well, just did everything right - rotation/corner entry, stopping, slaloms - other than not having much horsepower (100% stock drivetrain, making 166 whp). This was before everyone and their brother started autocrossing the 86 chassis, and the BRZ really crushed it that day. Good fun that day, and I aim to make our FR-S handle as well as Matt's BRZ did, if not better.
BILSTEIN PSS10 + REAR SHOCK MOUNT DEVELOPMENT
We have sold a good number of MCS coilovers for the 86 chassis but the price point does put some people off. We have been selling more and more Bilstein monotube coilovers and in early 2016 we reached out to a local autocrosser, Chase Reeves, to see if he would test a modified version on his BRZ. He jumped at the chance to become a Vorshlag Tester, and even though he's only been autocrossing for 2 years he goes to a LOT of these events, as well as road course club trials.
The Bilstein PSS10 kit for the 86 chassis is shown above. This kit has adjustable damping, uses an inverted strut and a 40mm shaft housing, and works well for "spirited street use" with the springs provided. There is one knob that adjusts both Rebound and Compression, but the Rebound changes are significantly larger. This is not the type of valving adjustment what you'd see in a true Motorsports monotube adjustable, but the price is often $800+ less than the entry level MCS TT1 kit - and the Bilstien kit also comes with ride height adjusters and springs, so the price difference is even larger.
Like we do with all shock kits that come with unmarked springs, the spring rates were measured here at Vorshlag (the right way) and we found them to be too soft for even semi-serious serious autocross or track use. The rates were almost the same as stock, to be honest. The spring rate charts we measured on our digital spring rating rig showed a front spring rate of about 172 #/in, and was somewhat linear. The rears had a more variable rate, from 175-275 #/in (avg rate of 207).
We tend to see these somewhat soft rates and oddly shaped "Tapered" springs on most Bilstein "PSS series" kits (PSS with non-adj valving and the PSS9 and PSS10 adjustables). The included springs are usually 60mm ID at one end (the bottom) and the OEM diameter at the top (huge). We almost always ditch these springs, for two reasons: softness and size. The rates above are too soft for use with a grippy 255mm tire - the car would have too much roll and dive when driven in competition.
To fix this we converted this kit with a 60mm coilover spring rate upgrade front and rear, which allowed us to ditch the giant OEM strut top mount and use our Vorshlag camber plates. We chose a linear 350 #/in rate Hyperco spring up front, with no tender spring. This works in conjunction with our 60mm upper perches and camber plates to convert this from an "OEM" style upper spring diameter to a much smaller 60mm spring. The smaller diameter spring allows for more inboard camber travel, as the 60mm spring takes up much less space laterally and allows the top of the strut to travel inboard more than the stock spring ever could. The 60mm sparing is also about half the weight of an OEM or the Bilstein kit's "tapered" spring.
Out back we used another 350 #/in spring from Hyperco We coupled this with a prototype set of Vorshlag spherical rear upper shock mounts (RSM) shown below, which we made on our CNC machines while the car was here for installation. We coupled the new spherical upper shock mount with our 60mm upper perches and an integral single-row sealed radial bearing, which deals with any spring rotation during compression. These have been used for testing on Chases BRZ since early March 2016 with zero issues, so we will move these into production soon.
If you look at the post above this one we have the spring rate charts for the factory BRZ and FRS springs. The stock BRZ had springs with rates of 162 #/in Front and 201 #/in Rear. The stock FRS curiously had a stiffer Rear rate at 221 #/in but a softer Front rate at 125 #/in. Like we have done in the past with PSS10 Bilsteins, we "about doubled" the spring rates, to get to what we felt would work right off the bat and within the PSS10's damping adjustment range. With an MCS coilover we tend to start with triple the front rates as our softest option, but the PSS10 damping doesn't have quite as much range as a Motorsport level shock like the MCS.
Since this was Chase's daily driver, car we kept the ride heights almost identical to stock, which he asked for. Normally that is tough on a Motorsports damper, and we could have gone an inch or more lower, but this is what he wanted and the Bilstein's adjustable ride heights allowed for this. We did gain a lot of negative camber and some positive caster with the camber plates and smaller diameter springs, and the total negative camber goes up with lower ride heights.
The setup sheet we did for this BRZ, like we do for all cars we install suspension on, shows the before and after ride heights and camber measurements. With camber maxed out (and front toe set to .125" total toe out, to minimize tire wear but still allow for a razor sharp turn-in) we saw -3.5° camber up front. With his 255/40/17 Dunlop Direzza Z2 tires on the 17x9" wheels above we knew this would work well, and camber adjustment is easy if he wants to change it.
The damping adjustment was also easy to dial in for street use, and Chase uses 2 out of 10 clicks from full soft for daily driving use. The rear knob is visible in the trunk, as shown above. The front strut's damping adjustment is at the bottom of the strut, since it is inverted. This means to access that knob you have to turn the wheel to full lock and reach in under the strut to get to it.
That is a picture of another PSS10 strut, from a Porsche 996 install we did a week before this BRZ. The strut's damping knobs are marked well and have very distinctive clicks, so once you visualize which way "soft" is, you can do this adjustment by reaching in and turning it blind.
Chase has been co-driving a Corvette for autocross this summer, but recently competed in two events in his BRZ. But he moved up to 245mm Hoosier A7 competition tires. This really wasn't what we designed this modified PSS10 kit and associated springs for, but damn if it isn't doing well anyway! He won CSP at his first event
on A7s and came in a close second this last weekend
, narrowly missing out on another win by .020 sec. That was running against some dedicated CSP Miatas (see in frame above) with flares, big tires, built motors, serious levels of prep and some of the fastest drivers in the region.
Not bad for 350#/in springs and PSS10s on an otherwise stock BRZ. Well he has a 20mm front Whiteline swaybar and the 16mm Whiteline rear bar as well.
Here is Chase's best autocross run
from the most recent SCCA event, where he came in a close 2nd in CSP. Once he gets back to doing more road course events, mostly SCCA Club Trials, I'll try to get some lap times from him on the new Bilstein / Vorshlag suspension.
VORSHLAG 2013 FR-S TEST CAR: REPAIRS
So I'm caught up on the last autocross I did in Matt's BRZ, and showed the PSS10 kit we modified and installed on Chase's BRZ. Now let's take a look at our new shop car - this 2013 FR-S. We had some pressing deadlines on some 86 parts we have built which we needed to verify
on an 86 chassis - a car that we could take mostly apart - so a tester's car on loan wasn't the solution here. There were also some new suspension bits we have dreamed up that it would help to have a stock 86 on hand to test with, too.
Amy has been wanting an 86 for the past year and a half. Strangely enough she never drove Matt's BRZ, but about 18 months ago she test drove a new 2015 FR-S one random Saturday - and she loved it! There was a series of cloverleaf exits next to the Scion dealer, she did all 4 of those twice each, and she was hooked. Even with the skinny Prius tires they come with it was still fun. The seats, greenhouse, visibility, stock handling, ergonomics - it all worked for her.
|31 Aug 2016 05:05 PM
continued from above
We have been keeping an eye on the used prices of these cars and recently she found some listings on Craigslist offered by a body shop / car dealer in our area that specializes in 86 cars. He usually buys them with some "history", fixes them up, and sells them at lower than normal prices. All on the up and up, no false records, and we knew this car had some light front end damage that was repaired with OEM parts. We checked out this car closely, test drove it, negotiated a great price and then bought it.
We had previously weighed Matt's BRZ at 2775 pounds (Limited model with some options) but this FR-S was a good bit lighter at 2634 pounds. This was with the trunk junk removed (see below), low fuel, but otherwise bone stock. Even had the heavy stock 17x7" wheels still on. The low fuel level and removal of the trunk junk skewed the front bias to nearly 57%
. Not what you'd expect in a front engine/RWD chassis, but I would reserve judgement on how this affects that car once I drove it on track. If it had massive understeer, I knew what to blame...
We pull all of the spare tire, jack and other junk from the trunk to get our initial baseline weights because that's how we race these cars
. We even ran it fairly low on fuel at our first road course test (see below). The low weight is what is so amazing about these cars... this weight is an astonishing 810 pounds lighter
than the 2016 Focus RS we have been doing track testing and suspension development with lately (see development thread here
This car was no cream puff, but we knew that going in, and it was reflected in the price. The front tires were corded, one ball joint was shot, and the brake pads were kaput. The video below shows how to test the ball joints on a car, and the left front was badly worn on this car. No worries.
Short video showing the worn ball joint + new control arm
The ball joint was not easily sourced from our normal wholesale parts suppliers (other than some aftermarket, racing style ball joints), and neither was the entire front control arm (other than some sketchy looking units on eBay). Many of the wholesale parts site listings for the 86 chassis said "under development" for the control arm and ball joints. WTH?
We were pressed for time so we ordered a new control arm (see above left) for the car from our local Subaru dealer, which had it to us the next day. $247 retail, ouch. I talk about the design issues we can see in the front control arms in the video above, but yea - I'm not a fan of the "axially opposed" bushing layout nor the thin, single layer, stamped steel control arm. Very easy to flex this arm, and that becomes important when you really add a lot of mechanical grip (see "Plans" below). Oh well, it was replaced and the front toe reset.
Since the tires were damaged from the bad ball joints, and we wanted to get a "stock baseline lap" in at our local road course, I went ahead and purchased some cheap OEM replacement tires for the car. I was looking for something in the factory 215/45/17 size with close to the 240 treadwear of the craptastic Michelin Primacy tires they come with. Not because I like those tires, but just to see similar grip for the baseline test lap. I found some "Firestone Firehawk Wide Oval Indy 500 XL" all-seasons on sale for $50/each
from TireRack. These were the right size and 320 treadwear
. Close enough!
As much as it pained me to buy what I consider to be "plebeian parts" to replace out the worn OEM bits, it was all for the baseline track test. So we picked up some cheap O'Reilys house brand, quiet "ceramic" style brake pads for the front and rear. $45/axle set, and we didn't even turn the rotors. We might be replacing all of this with aftermarket bits soon, so I wanted to keep costs low and just get it "as close to stock" as quickly as possible.
The engine is bone stock on this car and with 71,000 miles it seems to run as good as any other. We might test some new parts from a few suppliers we have worked with in the past under the hood - things that weren't yet developed in late 2013, when we had Matt's car available to use as a test vehicle.
There is some weird fake diffuser panel on the rear, which looks factory, supposedly part some option package I'm not familiar with. The exhaust looks pretty stock as well.
Pulling the front undertray off reminded me how convoluted and "non-flat" these front panels were. Maybe there's a need for a flat undertray? That's a zero point mod in NASA TT classes. Oh and that exhaust manifold and catalyst setup? Gah, what a mess. Haven't really kept up with the 86 scene to see what long tube headers are worthwhile, but we might have to try something to give this 200 hp 2.0L boxer a bit more "pep".
My shop manager Brad did a full track inspection and flushed the brake system on the FR-S with Motul RBF600
fluid. Why? Well I won't skimp on the brake fluid, even for a "baseline stock track test" like this. This is the FIRST upgrade we tell people as an HPDE instructor that is a MUST DO - the fluid. Craptasitc parts store DOT3 fluid boils at much lower temperatures, and when that happens your pedal pressure drops and you often go flying off track. Brake fluid pressure loss is never EVER fun, and we do this to even bone stock cars before they go to track events.
Setting the warm tires to 34 front & 30 psi rear, which made for decent wear patterns on the shoulders
The FR-S was now ready to take to Motorsport Ranch and run on one of their member days, which we did last Saturday. Normally we would load up the car into our enclosed trailer and go to the track but I had a customer's Corvette loaded for an autocross on Sunday. Two hot August days racing in a row was going to take its toll on me!
FR-S BASELINE TRACK TEST - MSR-C, AUGUST 27, 2016
In less than a week since buying the FR-S we had it repaired, filled with proper brake fluid, and ready for track use. We replaced the worn parts with as close to OEM spec as possible, to get a fair baseline lap time that represented these cars in stock form. We never got to do this in Matt's BRZ - because it wasn't my car, and he wasn't crazy about tracking his brand new BRZ. This cheaper, 4 year old FR-S was bought to be driven hard!
Photo and Video gallery:
We got out to the track at 7:40 am with the first cars going out at 8:00 am sharp, due to a fog delay. The pictures from the first session are pretty foggy.
In the first session I did what I *assumed* was the correct sequence to disable both the traction and stability control systems. Pressed the two separate buttons. Of course that didn't work and above about 30 mph the stability control system still kicked in. Amazingly the car would rotate fairly well but if the rear saw any "yaw" the dash would light up and it felt like the rear brakes were engaging. GRR.
Chase came out with his co-driver Mark and he showed me the crazy Konami Cheat Code sequence needed to disable the electronic nannies. Never seen such a crazy thing: E-brake up and down 3 times, brake pedal up and down 3 times, then E-brake twice more, than brake pedal twice - all within 30 seconds of starting the engine, with the coolant up to temp. Sure enough, the light came on and it never engaged once in the next session.
So instead of going through this crazy pedal sequence each time we want to drive this car hard, might be a good idea to invest in this "magic box"
that disables these two systems with a button press (or even defaults them off).
In-Car Video of the FR-S in session 3, best lap
I drove Scottish Joe's 2015 VW Mark7 GTI (below) in session 2, then went back out in the FR-S with the "pedal dance" sequence and took another second off my best lap time in session 3 (shown above). There was a LOT of traffic to deal with in every session, and even my best lap had a pass, but I still managed to run three laps within the same tenth of a second (best of 1:31.90) in this session. I guess that's as good as I can do, and we will call this our "Baseline Lap Time" for a stock FR-S there.
Some reference times for MSRC 1.7 CCW:
My quickest lap time in a street legal car here is a 1:17.25
, which I set as the class track record in 2014 (still holding) in our NASA TT3 classed 2011 Mustang GT. More recent NASA lap times from March 2016 in my TTC classed 1992 Corvette (nearly bone stock in every way) were a 1:21.9
and a 1:27.6
the same day in our TTD classed BMW E46 330 (with cord showing on the tires). Those times were all on DOT-legal Hoosier R-compounds (A6 for the Mustang, R7 for the other two). In mid July of this year I tested a stock 2016 Focus RS to the best of a 1:27.40
on the stock 235mm Michelin PSS tires. This same day in August I ran the 2015 VW GTI to a best of 1:28.10 (don't have the video up yet).
So yea, the FR-S is relatively slow compared to these other cars, but these skinny 215mm tires are CRAP; these other cars had between 90-250 more hp than the FR-S does (except the BMW 330, which made 195 whp). We have several upgrades planned that I will discuss below, and we will try to get a new lap time after each stage to quantify any gains or losses.
Considering how cheap the tires were, I was strangely impressed with how neutral the car handled
in stock form. Just a hint of understeer at the limit. And look at the lateral G traces that were logged on the AiM SOLO - they hovered at or even exceeded 1.0g in most corners. That's on 340 treadwear all seasons I paid fifty bucks a piece for! This is the first time I've tracked an 86 that was bone stock - the last time I ran some laps at ECR in Matt's BRZ (Nov 2012
, shown above) it already had 17x9" wheels, 245mm MPSS tires, Vorshlag camber plates and Swift lowering springs. It was showing closer to 1.3g lateral on those tires, which is nuts for street meat.
The coolant temp gauge also stayed rock solid all day, even as ambient temps rose to near 90°F, the needle never even got to the middle of the range. The stock brakes and O'Reily pads worked admirably, logging in the .9 to 1.0g range for braking each time, even if the fronts were billowing smoke
in the pits after my stints. I never had a long pedal or any hint of fade. And I was Left Foot Braking and late braking the crap out of this poor car.
So for once I'm not
going to dog on the car maker for making a crap suspension setup right out of the box. Could it have less dive and roll, more camber, grip and brake bite on a road course? Of course. We will address those things in time and share what we learn here.
PLANS AND FUTURE TESTING
We have a number of new 86 parts from some of our vendors that we would like to test on our own car before we add them to our website. Of course we will upgrade the suspension, likely with MCS or Bilstein coilovers and proper spring rates. We might develop a better OEM spring style camber plate solution before we go right to coilovers. We have made some OEM spring perch camber plate solutions lately that work with even the craziest factory top mount designs - like the S550 Mustang (below left) or the F22/F30 BMWs (below right).
Wheels and tires will be upgraded beyond the stock 17x7" and 215mm rubbish, of course. Deciding if we just hit the "easy button" and use the 17x9" Enkeis again or if we make a custom Forgestar 17" or 18" sized wheel instead. Once we get proper negative camber in the front of the car we can measure for wider wheels and tires. We will likely go with a BFG Rival-S or Bridgestone RE71R tire in the 255-275mm variety.
We might build up and run this car for a while in NASA Time Trial TTD or TTC classes, so we will work up some TT build sheets for both classes. I'm about to sell my TTC classed Corvette (above left) and Amy already has a TTD classed BMW 330 (above right), so maybe TTC makes more sense.
After that initial phase of product testing, well, we have some more serious plans in mind for this little FR-S. I will comment more about that at another time. Until then, thanks for reading.
Terry Fair - www.vorshlag.com
|17 Nov 2016 05:25 PM
Project update for November 17th, 2016:
It has only been a few months since my last update in our FR-S/BRZ development thread, but we've done some upgrades and development work on our red FR-S (which now has a name), Amy has run it at an autocross and driven it at a Track Night in America event.
Left: Amy has autocrossed the FR-S and tracked it. Right: Lap times from our Nov 10th track test (camber plates + brakes) were much faster!
We have installed some prototype suspension parts and a new Powerbrake big brake kit up front. After that we aligned the car then I track tested it at MSR-C to see how much quicker it is from our original stock baseline (a good bit, actually), all while still running the stock springs/swaybars/struts/tires. I am kind of surprised at how ... excited I am to see this car developed, because it is the "anti-Fair" car - a light, under-powered momentum car with skinny tires.
IMPRESSIONS AFTER 2 MONTHS OF OWNERSHIP
I shot this 6 minute in-car "Test drive" video a few weeks ago after owning this 2013 FR-S for almost exactly 2 months. In that time Amy has daily driven this car a lot and loves it, and even I have been warming up to it a bit. It was lighter than almost any RWD Coupe made in quite a while, and having a light yet rigid chassis matters SO MUCH.
Click here for 6 minute "test drive" video
If you watch the video above I talk for several minutes about the FR-S/BRZ chassis, explain why I think "car people" should test drive one. I compare the 86 chassis to the NC Miata (same time period, similar costs, similar weight) but explain the reasons why the 86 is a better track car than the MX5. I include some data - weights, front-to-rear bias, sales numbers - in the closed caption comments as well.
In the closing 30 seconds of the video above I give away a lot of the plans we have in store for this car, and a season of racing NASA TTD or TTC racing is probably not going to happen. If we stick to the plan we're going straight from stock engine to LS3, from 215 to 315mm tires. Because... America!
The same day as the 0-60mph test drive video, I spent about an hour washing and detailing the FR-S, which was the first time I think that I have cleaned this car up. It needed it, and still needs more detailing, but we have a lot of things we will change on the body before we really worry about paint detailing.
Stay tuned here for more development on this red FR-S. There is also a forum build thread detailing our Vorshlag Scion FR-S LSx Alpha Project
, that I wrapped up recently after we finished work on this customer V8 car. That will be a way to show the various parts and systems we need to tie-into and develop using this car. Somehow I will merge that Alpha thread with the updates in this generic BRZ/FR-S development thread, after this red FR-S has a V8. Who knows, I might just post the same update in both threads? We'll see.
Anyway, it was nice to spend a little time cleaning up this car and doing a little 0-60 mph test, to help get this project kicked off properly. If we are going to go crazy on this car, it does need a name...
NAMING CARS IS SILLY - BUT OFTEN NECESSARY?
I know a bunch of you reading this will roll your eyes when you see that we have named the red FR-S. I am doing the same thing here, but let me explain. So many times in the past when I would see famous car builders naming their project cars I would groan. How starved for attention do you have to be to "name" a car you are building, thinking it is somehow special enough and rare enough to deserve that?
The world's first BMW E36 LS1 Swap build - our original "Alpha car".
But over the 12 years that I have been building up Vorshlag we have had to concede that, yes, sometimes you need to name your build. At first I would inadvertently call a build an "Alpha" or "Beta", just to show that it was the first or second of a type of V8 swap on a chassis. Like our "E36 Alpha LS1" (see above) was the first BMW ever built with an LS1 V8, way back in 2002, and was known for many years as "The Alpha" in BMW circles.
Left: Our NASA TTC build on a 1992 Corvette was "Project Dangerzone". Right: My beater shop truck is "Truck Norris"
After seeing our first "million view" thread after building that car, my wife pointed out that we need to keep
naming our cars, even when I fought it. She is the one who came up with most of the names of subsequent shop car builds, and its always tricky to do without sounding silly. We've had some memorable ones such as: Jack Daniels, Dangerzone, Truck Norris, the GRM E30, and "The Red Car", to name a few.
Chainsaw (L) and Chainsaw Mouse (R) are being replaced by Chainsaw Massacre, a monster E46 M3 V8 build for a customer
Sometimes naming a car is a quick shorthand way for us to refer to one of many cars in our shop during the build period, or to quickly describe one of many cars from the same customer. We've built multiple cars for some customers, and one of them started naming each of his cars, which helped us when we conversed with him about multiple on-going projects: Chainsaw, Chainsaw Mouse, Chainsaw Massacre are three of his we built in a row. Even our own shop owned vehicles have become too numerous to describe quickly: We own FIVE different E46 BMWs right now, so a quick name is easier to use than "The white 330 Coupe... no, the other one!"
We called our red TT3 Mustang GT "The Red Car" but we have 4 different "red cars" right now
, so we have had to expand on that. And maybe Amy thought of a good one this time...
There was a spy comedy show called Get Smart
, released before I was born, that ran for 5 years, and had several follow up movies as recently as 2008. The original show was created by Mel Brooks and the main star was Don Adams, who played Maxwell Smart, Agent 86
. Most of you reading this know that the FR-S/BRZ/GT86 models are referred to as the 86
chassis globally. And that is where she came up with the name for the FR-S, Agent 86, and just "Max" for short. We're going to have to find a place to mount the shoe phone...?
So yea, this FR-S is called Agent 86
, another car with a corny name. We don't name every project we build but only the ones we feel are worth it. Hopefully this build will live up to the hype.
TRACK NIGHT at MSR-C, SEPTEMBER 27, 2016
We brought the FR-S out to this SCCA "Track Night In America" event, where Amy got three track sessions. I barely paid any attention to the FR-S that night as I was performing three separate track tests in the Focus RS we are using for suspension, wheel and other development work so I was busy. We were swapping wheels/tires, changing settings, and had all manner of cameras, data loggers, and timers to keep up with in the RS.
This new AWD 300 hp Focus RS is a bit of an understeering mess and required some pretty drastic suspension changes before we got the car to "calm down" on track and quit eating front tires. We have done several tests at MSR with this car, even back when it was bone stock (where it ran a 1:27.4 in July
). With the coilovers & camber plates it dropped to a 1:26.212
on the standard 235mm MPSS street tires, which was the 1st of 3 tests we did that night.
It dropped another HUGE chunk of time on the 275mm RE71R Bridgestones, shown above, running a best lap of 1:23.510 that night (which is only 1 second back from what I ran in a Corvette C6 Z06
). So from stock to "better suspension + better street tires" we found 4 seconds in the Focus, which is a massive drop in lap time. Yet we have found more than half that much time drop in our FR-S just with camber plates and brakes.
Check out the latest track test in this update, below.
This night wasn't about testing in the FR-S, as nothing had changed since we put it back to "refreshed stock form", so I didn't take any laps in it. Amy had three trouble-free sessions in the FR-S, but the front tires were starting to show some noticeable outer shoulder wear. Up to this point we have done ALL of our track testing on the same CCW 1.7 MSR course, so the right side tires are taking a beating, but especially the right front. The tread blocks were starting to chunk on that corner, just like we saw on the Focus RS. She ran some low 1:33 laps and had a blast, getting much needed seat time in the Scion.
AUTOCROSS WITH SCCA at LSP, October 23, 2016
Amy ran "Agent 86" in bone stock form at this autocross, her first in the red Scion. She ran in the local Women's class with a C Street PAX and had fun on the same CHEAP
320 treadwear 215mm tires. I was working at the shop that day, but she wanted to get one autocross event under her belt while it was still stock, to see the difference before and after. The more testing we can do along the path of mods we have planned, the better.
These cars in stock form are "fun" to drive, but they are not exactly fast. The tires they come with from the factory are a HUGE limitation, and the soft spring rates don't exactly make for flat cornering. Amy has a lot of experience autocrossing and has multiple SCCA National Championships under her belt, so her overall ranking in PAX will be a good metric for how fast and the car is at the moment - or not.
This was a typical course for our SCCA region, and she said she had a lot of fun slinging the car around. C Street class allows the dampers, swaybars and tires to be changed (any 200+ treadwear tires on the stock sized wheels).
Since this FR-S was still on the stock dampers, swaybars and tires, it would be handicapped pretty hard, but it is just where the car happens to be right now. The images above (which were purchased from two different photographers) show the score: lots of body roll, positive camber on the outside front tires. Damn this car needs some camber and spring rate, in a bad way!
Click here for the in-car video from Amy's best autocross run in stock form
Her runs on video all looked pretty spot-on to me, and she said it was easy to push the car to the limits, but that "the tires were CRAP". She had clean runs all day and placed 3 out of 4 in the PAXed Women's class. Jen Maxcy was in a proper STX prepped BMW E36 328is in the same class and was 4.5 seconds head of her times, so the lack of tires and class prep definitely showed here.
Amy placed 68th out of 151 times in the overall PAX standings
, so we have a long way to go before the car is setting FTD or Top PAX at autocrosses (3.6 seconds back from Top PAX time). We figured as much, and while SCCA autocross classing won't play a real part in this build, it is a good metric to look at for overall competitiveness.
PROTOTYPE CAMBER PLATE FOR USE WITH OEM SPRINGS
As promised in my August update we wanted to use this red FR-S for development of a new camber plate design that works with the OEM spring diameter. We were unsure of how to go about this design but started with a handful of existing parts and designed a few more to see if we could make something that fit the tight constraints of the 86 chassis as well as the OEM spring limitations.
Left: Existing GD/86 plate for coilovers. Right: prototype 86 camber plate matches factory stack-up height, for OEM spring use
Our existing Subaru GD / 86 camber plate design (above left) works great with coilover springs with inner diameters of 2.25", 60mm or 2.5". We've sold hundreds of sets for these two Subaru chassis over the years but the camber plate + upper perch design is tough to replicate in the same space as the "short envelope" that the factory Subaru top mount + OEM upper spring perch fit inside.
The trick that Subaru pulls on many of their strut top mounts is to move the mount above the top surface of the strut tower sheet metal, and then make the upper perch domed so that it sits higher as well. These two aspects gain them some added bump travel, but it makes it difficult to replicate in an aftermarket camber-adjustable top mount design.
The image above left shows the amount the factory strut top mount "pokes" above the strut tower. The image at right is the bare tower without a top mount or strut installed. The round opening is rather large, and the trick we used to match the stock bits was putting the spherical bearing holder above the main camber plate, which gains some travel and keeps the stack-up short. We did so knowing that we would lose some camber travel, and thought we might have to make a unique main plate that lost the positive caster offset in our original GD / 86 camber plate design.
|17 Nov 2016 05:26 PM
continued from above
To minimize "stack-up height" of the camber plate and perch we used our "large diameter" radial bearing shown at far right
After we had the main plate and bearing holder parts selected, Jason designed a super short OEM style spring perch. This billet aluminum part uses our unique sealed radial bearing in the perch, like all of our designs, which isolate steering loads away from the spherical bearing. The spherical should only pivot axially, and never rotating (or it wears out VERY quickly). This "large bearing" design also isolates the spring forces from the spherical, making it last even longer. You can see the perch installed above, during mock-up testing on Agent 86. We liked what we saw and then moved forward with the installation on the factory strut with the stock spring and rubber spring isolator.
With the spring compressed the stock top mount and upper spring perch were removed and the prototype camber plate + perch were installed onto the strut. We arranged the new components to retain the exact length and compressed height of the stock spring/strut/top mount. This new strut assembly was then installed on each side.
This setup would still allow for the added fixed amount of positive caster that our original GD design does, as well as considerable camber adjustment range. How much? The alignment rack would tell us. We were also able to use an existing, proven set of spherical bearing holder components - that don't have to shrink in size (and strength) to get every millimeter of adjustment, like some of the designs we see on competing 86 OEM plates. I wasn't willing to lose the massive strength advantage we have on our other designs, yet we could not afford to raise or lower the ride height with this OEM spring style design.
The new setup was able to keep the same ride height yet add an additional 1.9 degrees of inboard camber adjustment and reached +5.6 to 5.7° of caster. The final alignment sheet is shown below.
The max camber setting was -2.9° up front, which was more than we had hoped for, which was great. Initially we set this car at -2.2° front camber and 0 toe for use with the stock tires and suspension, for street driving. We drove it like this for a week and it made not a peep of noise or have any weird driving feel, so we tweaked it to up to -2.5° front camber for our next track test. With lowering springs installed the measured camber settings would be even higher - more negative - as they always do when you lower ride height on a McPherson strut car.
Jason (engineer) and Ryan (CNC operator), shown above left, worked on this one together and took a lot of measurements. I wanted this design to be RIGHT with no noise, no raising or lowering of ride heights, and plenty of camber and caster. Donnie (above right) had these struts on and off the car several times for measurement, testing, alignment checks, post-test inspections, and more.
After we had this design installed and street tested for a coupe of weeks we planned a track test at Motorsport Ranch track with the 86 as well as our TTD E46 BMW and a customers S197 Mustang race car. At the same time we added these camber plates we also upgrade the brakes. Because why not??
POWERBRAKE FRONT BRAKE UPGRADE
If you have been reading my build threads lately you may have seen this brand of brake caliper and rotor on other cars we have been working with. Powerbrake products are Motorsports grade brake caliper and rotor kits designed and machined in-house in South Africa. Their rotor rings are cast in Italy and machined in-house as well. The quality is second to none, but due to currency advantages for the US Dollar this is one of those few times you can "get more than you pay for."
The first Powerbrake branded kit we installed was used on our BMW E46 330 (above) we built for NASA TTD competition early in the 2016 season. This kit uses their "large" 4 piston caliper and a reasonably sized rotor - which is designed to fit under most 17" diameter wheels.
We have used these brakes on the E46 330 now for 5 race weekends or track tests and many hundreds of street miles with excellent results. We even had a double-driver weekend where Jon and I both drove it in back-to-back sessions for 2 days and the brakes never had a single issue. ROCK SOLID brakes that feel truly amazing. The difference in braking feel and confidence over OEM brakes really is indescribable until you drive on true Motorsports level brakes.
Pad and rotor wear has been much lower than before with the OEM brakes and race pads, which means they are lasting much longer. We have extrapolated this over the long run, and it looks like the "cost-per-lap" of the Powerbrake setup will be lower than the OEM rotors & race pad expenses, and that's what many other users are seeing.
Powerbrake X-Line X4ES 4-piston 325x28mm FRONT race brake kit for Subaru BRZ & Scion FR-S
After using the big 4 piston front Powerbrake kit on the 330 I wanted to test out the Powerbrake solution for the front of the FR-S. Luckily they had just released an updated caliper design for 2016 called the PBX4, which uses two pads per caliper (unlike the 4 piston caliper on our 330, an older design that used 4 "padlets" per caliper). Above is the Powerbrake X-Line front brake kit for the Subaru BRZ & Scion FR-S. This features their new X4ES 4-piston caliper and 325mm x 28mm 2-piece rotors.
The massive 4-piston Powerbrake X4ES caliper (at left) is 5 lbs lighter than the iron factory 2-piston FR-S front caliper (at right)
The calipers are big beefy things made from of billet aluminum. This is more expensive than using a near-net-shape casting in aluminum, but it makes for a more rigid caliper - and this is what separates Motorsport calipers from even upgraded OEM aluminum calipers like "factory Brembos". This article
by StopTech discusses "monoblock" vs 2-piece caliper designs like this, and their conclusions make sense.
There are dozens of other features inside the calipers that make them better for Motorsport use as well. A quick look shows the stainless steel wear blocks, the gas ported stainless pistons, integral bridge, and the variable piston diameters which go into the engineered caliper solutions they produce. Vorshlag is working directly with the U.S. and South African Powerbrake engineer teams to help develop, test, and market their solutions for a variety of Asian, German, and a growing list of domestics.
After the FR-S front brake kit arrived we took measurements, weighed everything, and mocked the kit up on our car for installation pictures.
Many of the popular "big brake kits" (BBK) upgrades sold today are made to be HUGE, with rotors that reach 355mm or even 385mm in diameter. Those rotor sizes force drivers into 18" or even 19" wheel sizes. I could talk for an hour about wheel & tire diameters, sidewall heights, spring rates of tires, unnecessary mass, and tire selections in differing wheel diameters... but long story short, a massively larger diameter rotor can often be a determent on lightweight cars being used with sub-19" wheel diameters.
The larger 2-piece Powerbrake 325x28mm rotors are only a hair heavier than stock
As you can see in the pictures above, the Powerbrake rotors are indeed bigger, but in this kit they are not huge (and fit within most 17" wheels). These rotors manage heat with a thicker rotor, better venting design, and a lighter aluminum hat with (radial) floating hardware. All of these design features help improve brake feel and heat dissipation. Weight is lowered over stock, which is always a bonus, and between the caliper and rotor the Powerbrake system lost about 4.5 pounds per side over the smaller stock bits.
Another major gain in braking stability and heat management are in the calipers. This "X4ES" caliper has a slightly larger pad surface area but a much larger chunk of billet aluminum makes up the caliper structure itself. This provides a more stable backbone to the caliper under extreme heat and clamping force, which allows for much less distortion and better feel.
The FR-S/BRZ is a light (2650-2750 pounds) chassis and comes with a 17" wheel, and due to fender limits most folks end up with a 17x9" wheel and 255mm tire as the most common "wide wheel" used on the 86 with stock fenders. So in this instance the 4 piston caliper and moderate rotor sizes fit the needs nicely.
Our car may or may not move to this popular 17x9" wheel setup, but our former blue 2013 BRZ test mule did definitely go with that size (in both D-Force and Enkei RPF1) on 2 different sets of aftermarket wheels. This is the wheel & tire what we recommend for most of our 86 customers, so we felt the Powerbrake kit made to fit inside a 17" wheel was worth testing on our latest FR-S.
You sharp-eyed readers might notice that this rotor is on the wrong side - this was put on just for mock-up
When Powerbrake sent us this demo kit for our studio pictures we test fit the kit to our car with green tape on all of the metal surfaces, to avoid scratching the calipers/rotors in case we didn't use it. But it looked so good, and with only a 5mm spacer we realized that we could use these with the factory wheels and tires, so we kept these for use on Agent 86.
We also test fit these brakes (rotor + caliper) inside several other wheels one day, including a factory Subaru BRZ wheel, shown above. Like the factory 17x7" FR-S wheel, the BRZ wheel also required a 5mm spacer to clear the large Powerbrake X4ES 4-piston billet caliper. The other aftermarket wheels we tested did not.
The popular 17x8" Rota wheel made for the 86 chassis was tested, and the common 17x9" fitments should fit as well or better - except for maybe the Enkei RPF1, which typically has terrible caliper and rotor clearance (they use a design trick to keep these wheels light, which gobbles up caliper room). We will test an Enkei on our car with the Powerbrakes soon and post that picture here.
We love the RPF1 in 17x9" for the 86 chassis, but this wheel is notorious for poor caliper clearance
After firming up the long term plans for this car, that included the big brakes, we purchased this kit for Agent 86. We felt that even with the big wheels and tires we are moving to that the car will always be light, and this Powerbrake kit should still fit our needs long term. Donnie had this front setup installed in about 45 minutes, with a brake bleed it was an hour of work. 100% bolt on job, no mysteries, and their instructions were excellent. Calipers come with temp strips in 2 ranges and rotors have 5 stripes of temp sensitive paint, to help you see brake temps. Legit.
I don't like talking prices in these threads because then it all gets too "salesy", but this X4ES front caliper and rotor setup is remarkably well priced. If you want to know more, you know where to ask. These fit the car great, looked amazing, but we just needed to make the stock wheels fit the caliper...
|17 Nov 2016 05:26 PM
continued from above
ADDING 5MM SPACERS AND LONGER WHEEL STUDS
Like the BRZ wheel, the factory 17x7" FR-S wheel is very "flat" and the spoke design is not conducive to an easy big brake upgrade. We knew from our mock-ups that we needed a 5mm spacer to clear the larger caliper with the stock wheels, but most other wheels we tested needed nothing. We haven't planned on keeping the stock wheels for much longer but we did want to get at least one more track test in with the tiny 215mm tires and 17x7" wheels to show just how much lap time drop we could attribute to the camber and brake upgrade.
The factory wheel studs on the 86 chassis are pretty short, and like most OEM fitments don't allow for even a narrow 5mm spacer. What you are looking for is proper thread engagement on the lug nuts, and the rule is "one diameter worth of threads". That means that on our M12 studs we need 12mm of depth of thread engagement with the lug nuts, after installing the spacer.
We tested with the spacer installed above and and it looked like the studs would be to short. We counted the turns on a lug nut anyway, and it was 2 threads short, so it was time for longer wheel studs. This was something we covered earlier in this build thread, where we installed 65mm long wheel studs on the blue BRZ and an FR-S. But I'll show it in more detail here....
The hubs are a unit bearing design that bolts to the front uprights, so those were removed (see above left). I snapped a quick pic of the 65mm studs we offer and have tested on these cars, both Subarus and 86 chassis cars alike. We also keep these 5mm thick, dual pattern 4 & 5 lug wheel spacers on hand. Being this thin they don't need or can even have an extended hub ring.
Pushing out the stock studs from the hubs was easy with our 30 ton air-over-hydraulic press. Takes a few seconds for each one, with some spacer plates used to clear the raised bearing section of the hubs. You can see the OEM length next to our 65mm studs above, too.
Installing the longer wheel studs was easy, just had to use a "spacer" to clear the raised section of the hub again. This spacer ended up being a second-hand bolt, but it worked fine. The splined ends of the studs need to be pressed in with a press like this, and "pulling" the studs in with a lug nut and impact gun is kind of a janky work-around. It always trashes the face of the lug nut, and always seems to cause minor damage to the stud during the install.
With the studs installed in the front hubs (we didn't do the rears at this time, but documented that earlier in this thread) we then looked at the factory "closed" lug nuts. Those are usually a problem with long wheel studs because the added length can keep the lug nut from installing all the way. An open lug nut is preferred and the "extended seat" long reach M12 lug nuts we make for Subarus fit the bill. Bigger nuts are always useful...
With the longer studs and 5mm wheel spacer installed you can see that the stock wheel spokes clear the caliper by about .200", which is double the clearance of factory 19x9" Mustang wheels to the factory Brembos, so no worries. We're gonna track test all of this properly, don't worry...
MSR TRACK TEST, NOVEMBER 10, 2016
Right about the time we wrapped up the prototype camber plate and Powerbrake install on the FR-S we had 2 other cars undergoing similar development - and all 3 needed to be track tested. We loaded up our NASA TTD prepped BMW 330 in the trailer, Jon drove the FR-S, and Jamie Beck brought his ST2 Mustang race car out to a member day on a Thursday in November.
The weather was overcast but cool (58-72°F while we were running) and I took 5 test sessions that day, driving all 3 cars at least once and riding with Jamie in another. While it does take time and money to do these tests, nothing helps prove an upgrade like lap times at the same track.
As with all MSR member days you have to wear full racing gear, head to toe, which keeps the squid factor down. We tend to go on Fridays but this time a Thursday test fit our schedules better, and we ended up having less traffic to work around, which was nice.
All 3 cars we brought this day happened to have Powerbrake upgraded brakes, with the FR-S and ST2 Mustang both having new/untested setups. The Mustang had a prototype 6-piston front and 4-piston rear setup using 350mm rotors, which fit this car's capabilities since it has 18x11" wheels and 315mm Hoosier R7s.
Jon and I each ran the E46 330 for a session and I put in one session in the FR-S, then 3 sessions testing and coaching in the Mustang. We ran the E46 back in March with NASA to a 1:27.604 best lap and this time I ran a 1:25.075 lap
, for a 2.6 second drop in time. Even after dropping 250 pounds over the summer this BMW car is still 300 pounds heavier than the FR-S, but it does have a 245mm R7 tire on a 17x10" wheel, so it was making closer to 1.3g lateral grip.
The in-car video above
shows the best lap on the FR-S, plus a little clip where I tried a "2 in the dirt" line on another lap. I tried to take a certain fast corner "full throttle" and couldn't quite make it work with this setup, heh. Only time I have touched dirt in all of our test sessions here since March, but I had to try it.
Back in our August 31st "baseline stock" lap testing I netted a best lap of 1:31.90 after 3 sessions of driving the stock FR-S. With the only changes being added camber and the Powerbrake front setup, I managed to drop 2.3 seconds netting a best lap of 1:29.630 this time. That's still with total CRAP tires that cost $50 each. That picture of the FR-S (above left) is after I passed the gutted E46 M3 race car on Conti slicks. Gotta admit, that felt good, but he was still warming up his tires. But still.
Here's a listing of cars and lap times we have run at MSR on this same 1.7 mile CCW configuration:
- https://youtu.be/Cs6AF436ykE - 1:31.90 in a stock 2013 Scion FR-S
- https://youtu.be/_I4ltM6plFQ - 1:29.630 in the 2013 Scion FR-S with camber and front brake upgrade, last week
- https://youtu.be/fpWyzzf-pHk - 1:27.40 in a stock 2016 Focus RS
- https://youtu.be/4zIW-9T-vb0 - 1:26.212 in the Focus RS on coilovers and camber (which then ran a 1:23.658 on 275 Bridgestones later that day)
- https://youtu.be/YvCH0aWGt-A - 1:25.075 in our TTD prepped E46 330 (195 whp) last week
- https://youtu.be/1_B2u_fOnww - 1:22.63 in the stock 2012 C6 Z06
- https://youtu.be/athEpfLRH3o - 1:22.56 in the modded 2013 1LE Camaro on Hankook RS-3 tires
- https://youtu.be/Ga1GoC-H9dM - 1:21.90 in our TTC prepped 1992 Corvette (288 whp)
- https://youtu.be/6Rpepzil8FI - 1:21.89 in the stock 2017 Corvette C7 Grand Sport
- https://vorshlag.smugmug.com/Racing-Events/NASA-MSR-030814/i-ZT7bnbx/A - 1:17.250 in our TT3 Prepped 2011 Mustang GT on 335/345 Hoosier A7 (447 whp)
I will usually say that laps here under 1:30 are respectable for street cars, running under 1:25 is pretty fast, and under 1:20 is hauling ass. So the FR-S at a 1:29.630
is at least getting "respectable" now. Technically this would be classed as a NASA TTD car, so we're not exactly breaking any track records here yet, but we have barely started to prep the car. These tires are REALLY holding us back on lap times, yet still make 1.10g lateral grip. Not bad for fiddy bucks.
We show the tire wear at the end of the track video, but these "new in August" tires had already taken a beating at the August and September track days without any camber up front - both "outside" tires (right side) showed plenty of wear. These tires were swapped front to rear before this event, and the front tire wear was was noticeably lower after getting -2.5° camber dialed in. Not surprising, right? Yet I was shocked at how much time we dropped with just "brakes and camber". A 2.3 second change is a big drop. Just encourages us to keep going and see how quick we can get this thing!
We still have an aggressive development plan for this car and I will show what we've done over the winter when we have some mods worth showing. The prototype OEM-style camber plate solution tested on our FR-S has already been released and we have production components for this 86 chassis. The 4-piston Powerbrake kit is also available.
Do we go back to a tried-and-true MCS TT1 and 17x9" wheel setup just for lap time testing on our red FR-S?
We're torn on what wheel/tire package to go with on Agent 86 next, and have debated this internally at great length. We know the 17x9" wheel / 255mm tire is good for an easy 3 second drop but do we pause there, or jump ahead to the BIG wheel and tire package we want to use with V8 power? Same goes for the coilover shock decisions - do we test a Bilstein PSS10 or MCS TT1 first, or jump to the MCS RR2 setup? Choices, choices...
Track testing this current BRZ coilover + 17x9" setup will give us the data to fill in the gaps...
To test that "next step" on track we are going to borrow Chase Reeves BRZ, which I mentioned last time. We used his car for PSS10 / Hyperco coilovers / Vorshlag camber plate / Vorshlag RSM testing and he loves the setup. He also has the 9" wide wheels and stickier tires on it, which we will try to take to MSR soon and get laps on. Will be a good metric of what to expect when you step up the mod ladder.
Terry Fair - www.vorshlag.com