Hello,

I wanted to ask how important it was to stay away from hitting the bumpstops during tracking or autocross or even daily driving. For a relatively mild setup for integra, Ground Control sells a kit that's 350 lbs/in, 9" front and 250 / 8" rear. Ok, well I think there might be a problem here. Let's say I have to do hard braking on a downhill, which throws 90% of the car's weight to the front. (not sure if this number is reasonable). That means that the weight on each front tire is 1200 lbs. Front motion ratio is 1.5, so the force on the spring is 1822 lbs. For a 350 spring, that will compress it by 5.2". But wait, a 9" spring only has about 5.5" stroke. So you are really close to coil bind, plus you are supposed to hit the bumpstops before that, so at this point you are on the bumpstops. And then if you actually hit a bump in the road...

The same situation applies if you are cornering hard and put most of the weight on the outside wheels, except that in this case, the swaybar is helping you out a bit.

I guess another question is if I should get longer springs? I plan to daily drive the car over bumpy roads, so that's why I'm using such a "low" spring rate.

 

Holy crap...you like math.

 

The motion ratio means that the force acting at the wheel is less than the force of the spring. The force on the spring does not change, its just 100% of the force on the spring.

You'll be on the bumpstops before you bind the springs. A bumpstop as it's own spring rate, and while it's not a good idea to be on the bumpstops often, they are there for a reason.