Go to previous topic
Go to next topic
Last Post 10 Nov 2016 11:46 AM by  Grintch
POWER to Weight calculations
 5 Replies
Author Messages
rj
New Member
New Member
Posts:1


--
31 Oct 2016 01:12 PM

    New member Here,

    As two guys looking to go racing ( weekend warriors only / Tight budget ! ), we would like any / all in put on sorting out which set up to build .

    I'm of the mind set that the lighter the better. IE : a small block  ( 289-351w )  in say a 65 Mustang  coupe.  My friend would like to go say a big block ( 428-460 ) in a bigger / heavier Mustang ( 71-73 ).  If your of the mind set that "torque matters most" , then a big block delivers more of that and sooner in a given RPM range BUT at the expense of weight . So I'm thinking to sort this out we need a way to calculate  Power / Torque  (at a given RPM ) to the cars Weight . We are aware that getting a heavier car to hand will be an investment in aftermarket suspension parts . But I'm thinking that should not be a budget buster .  ???? I'm I missing something ??? Should we be looking to go the old school COBRA approach  ?  Aluminum headed big block in a light weight Mustang. Like I mentioned ... tight budget , as in we can't afford a Ford Racing small block 427 engine.   HELP !

    rjohnson999
    Basic Member
    Basic Member
    Posts:178


    --
    31 Oct 2016 09:06 PM

    Before you do any calculating you need to look at the various rule books for each organization and type of racing you want to do to see if that big block is even an option, what class it would be in, and then have a look at some recent results to get an idea of whether your heavy weight will be in the ball park or just circulating the parking lot.

    rj
    New Member
    New Member
    Posts:1


    --
    01 Nov 2016 12:32 AM

    From what I have been told , like drag racing , there is a SCCA class that allows each of the 3 "Builds "  we are considering.

    I'm thinking the next step is to crunch the numbers , as to which build is worth doing . Both for budget  concerns and "Fun Factor" . ie : TRACK & Street considerations.  Any one know of the math needed to justify one build over the other two ?

    47CP
    Veteran Member
    Veteran Member
    Posts:2742


    --
    02 Nov 2016 01:52 PM

    What kind of "racing" are you talking?  Wheel to Wheel on track?   Autocross?   Track Days?  

    There likely is not a simple answer to your question.  

     

    DaveW

    Bejay
    Basic Member
    Basic Member
    Posts:244


    --
    02 Nov 2016 05:48 PM
    If autocross, then a formula including power+weight+drive tire width might be needed.
    Grintch
    Basic Member
    Basic Member
    Posts:259


    --
    10 Nov 2016 11:46 AM
    The what class question is very important.

    And I can't think of a single SCCA class where a big block 71 Mustang would be a good choice.

    More power makes you faster on the straight. Lighter makes you faster in the braking zones AND corners. If its an autocross (CAM) car, you spend a lot more time cornering than on the straights where more power would help.

    More power also generally costs more, and can greatly increase your consumables cost for fuel, tires, brakes, etc. So it is not a good low budget option.


    ---