I have an '88 IROC and just lowered my car with the ST Suspension springs. Looks pretty good! I just want to get the rear up a little higher. I was thinking about using a rear spring spacer to do this. I heard that whatever size spacer you use, the amount of lift double. For example, if you use a .5" spacer it'll lift the car about 1". Does anybody have experience with this? Is that accurate?

 

I used the rear isolators I bought from a dealership a few years ago. They were for a '98 T/A and lifted the rear just a smidge so that it had a more aggressive stance to it.

 

Not true.

LOOK AT the parts in question; you'll observe that there is NO leverage or mechanical advantage anywhere in it, unlike front springs, in which that "hearing" is less inaccurate.

.5" spacer = .5" lift

 

Any spacer you put between the spring and chassis will lift the car the exact amount as the spacer size. Theres nothing to double because the rear springs are more or less straight up and down. If you want it 1/2" higher in the rear, a 1/2" spacer is what you want.

 

I appreciate everyone's feedback. That's what i was thinking I just wanted to be sure before I bought the parts.

Blacksunshine....your stance looks awesome. That's about what i'm going for. What size isolator did you use?

 

It was the stock isolators from a '98 Trans Am. IIRC, they are ~3/4-1", but don't quote me on that.

 

That’s about right. The 4th gen isolators add about 1” of rear static ride height compared to the 3rd gen isolators. I used Eibach 1” lowering springs on all 4 corners and then swapped the rear isolators to 4th gen to bring the rear back to stock ride height. Gives the car a nice forward rake.