A question for suspension guru's:

I am used to seeing front springs with higher rates than the rear for cars that are front heavy. With the RX-8 being pretty close to a 50:50 balance, why do we still have front springs that are 40-50% stiffer than rear? this is true of the stockers and all aftermarket. What is the benefit of heavier springs on the front?

 

The suspension geometry in the front and rear isn't the same, so the lever arm on the spring is different in the front and rear.

The rear spring works basically directly on the wheel, moving 1:1 with the wheel. The front spring is hooked to the A-arm about 70% out, so it moves less than the wheel.

The spring rates at the tires are much closer matched than the direct spring rates due to this.

 

I'm sure the nose-dive that occurs when braking is another reason, too.

 

The 8 doesn't dive much under braking since the CG is pretty close to the center of the wheels.

If the front was really sprung that much higher than the rear, the car would understeer like mad. The srping rates are not there to control brake dive. That's what shocks are for.

 

well it would appear that mr. dsm's got this one covered, so i'll just sit back & watch.