68Malibu383

Have an '03 Z06 that I ocassionally track at VIR. Previous owner dropped the car all the way down on factory bolts with factory sized tires (the rubbers below the leaf springs are still in place). Car had no rake and experienced front lift around 120 mph and up. I raised the front 0.75" and the rear 1.25" That eliminated the problem.

I now have 295/35 18s all the way around, which raised the front end 0.4". I wanted to lower the front in order to retain the rake. I was only able to turn the front bolts 2.5 turns before they bottomed.

From what I have read, a car dropped all the way down on factory bolts, will have poor handling due to suspension bottoming. If the front bolts are 1/2 turn from bottom, and the factory rubbers are still in place, is that too low for proper suspension function? Any idea what the range would be to still retain decent handling (ie, 2, 3, 6 turns of bolt from bottom)?

My other option would be to raise the front back to where I had it, then raise the rear to get the rake back.

Thanks for input!

davidfarmer

I dont think "all the way down" is too low on most cars, all the way down an cutting them is getting too low. Unless your springs have dropped a lot, you are probably ok lowered on the OEM adjusters.

Its the geometry that's the problem, not bottoming. The upper control arm is shorter than the lower, and it will start moving the wheels in/out instead of up/down as you get lower

fatbillybob

lower control arm horizontal is the lowest you can go. Also shocks need to be set up for the reduced travel. You don't want to bottom out. Almost all aftermarket performance shocks penske jrz take this in account with shorter shock body. You can't lower the Z06 spring enough on bolts because it has a lot of camber like a snow ski. Take a T1 spring or hyperco performance spring from VanSteel and the spring rate goes up and the spring is flatter so that the bolts are more in the middle of the range to adjust. A full coilover will also solve that problem having more adjustability.

68Malibu383

Thanks, guys. Very helpful.

I do have the shorter Bilstein shocks.