For calculating shock motion ratios everyone seems to use .70 for the front and .67 for the rear. I agree with these numbers "somewhat" but when you lower the car the angle of the shock changes. At a 13" ride hieght I came up with .680 for the front and .670 for the rear. I measured everything myself. As the car lowers more then 13" hub-to-fender ride height the angle of the shock also lowers which in return changing the motion ratio.

So between comparing set-up don't we need to know the exact ride height of that car and the angle of the shock at that height? A small change in motion ratio can make a difference in roll rates and wheel rates.



When calcuating roll rates and such shouldnt we account for this change as the car compresses/rebounds through out it's usable range. Are we only calcuating 1 lb/in and the angle of shock doesn't change enough to make a difference?


Thanks,

Josh

 

I wouldn't worry about it. Bolt parts on. Drive. Don't like? Change. All the numbers in the world won't help you fine tune the car and on top of that, you'll constantly have to adapt the tune to the surface.

Who Dat!

 

I agree with Matt. The numbers may get you to a good start but I wouldn't be bound by your findings/shortcomings based on what the numbers tell you. Ultimately you'll need to find what works and be able to adjust accordingly to each site.