SCCAForums.com

I'd like to test the strutbars i have for actual improvements, so explain some methods and results you've seen.

I've got upper and lower front strutbars and an upper rear bar.

 

Any tips on acquiring a skid pad area? 

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Rob P.

The new--05' Subaru WRX
The old--04' VW GTI
->the damage: http://i206.photobucket.com/albums/bb198/penderperson/WRX/pics005.jpg

Nobody tests the effectiveness of their strutbars? 

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Rob P.

The new--05' Subaru WRX
The old--04' VW GTI
->the damage: http://i206.photobucket.com/albums/bb198/penderperson/WRX/pics005.jpg

VW_rob_85:

Nobody tests the effectiveness of their strutbars? 

 

I got one off of EBay; my car now has 23.2more HP and has doubled it's MPG.

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Erik B.
Wisconsin Autocrossers, Inc
www.waiautox.org ___/\___/\___/\___/\___/\___
2007 Mazda6
2000 "Fozda" ZX2 S/R--STS Anti-Civic

http://www.tercelreference.com/project_development/rear_strut_bar/rear_strut_bar.html

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Rob P.

The new--05' Subaru WRX
The old--04' VW GTI
->the damage: http://i206.photobucket.com/albums/bb198/penderperson/WRX/pics005.jpg

Here is another interesting take on strut bars: Stress Bar Theory

 I'm no engineer so I can't speak to the conclusions, but it seems logical to me. I'd love to hear some engineering types critique the analysis.
 

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'89 RX-7 GTU
Speed in Gears Calculator

Well, the geometry and force diagrams are all in order.  However, the real question is what will result from a 333 pound force being applied to the frame at the strut mount?  The author tells you how much camber change will result from a frame motion of 0.2 inches, but does not give any indication of how much frame motion is likely to occur.  It would also be interesting to see the strain gauge data that the author refers to in the second segment of the article.

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John S.
S2000 #42as

Here's what I've done to determine actual movement:

1.  Make a pseudo STB using two pieces of tubing that slide togehter somewhat snugly.

2.  Mount the STB normally.

3.  Safely block the car from rolling, jack up one side of the car, place it on jack stands, and remove both wheels.

4.  Using two high lift (18 to 24") floor jacks placed under the front and rear suspensions on the side of the car with the wheels removed, raise the car and remove the jack stands.

5.  Lower the car to normal static ride height.

6.  Carefully mark the overlap joint on the two tubes that make up the pseudo STB.

7.  Carefully raise the car, maintaining the desired rake front to rear, until you see a 30 degree roll angle.  Place jackstand back under the car.

8.  Carefully mark the overlap joint on the two tubes that make up the pseudo STB.

9.  Put the wheels back on the car and put it back on the ground.

10.  Remove the pseudo STB and measure the distance between the two marks.  That will give you a very rough idea of the deflection in the strut towers.  

 

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John Coffey
http://www.betamotorsports.com

Excellent implementation, that sounds pretty solid and it will vary between cars.  To add to that, if you want to know how much compression the towers feel per the author, you could use the same method:

 

Take an oring and place it at the overlap joint(mark it first), then take some dips similar to AX courses/speeds(mark this), then take some progressively larger bumps and record as you desire. 

 

Wouldn't this distance show the slop/possible camber change of the chassis during bumps?

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Rob P.

The new--05' Subaru WRX
The old--04' VW GTI
->the damage: http://i206.photobucket.com/albums/bb198/penderperson/WRX/pics005.jpg