ride height - autoslalom
Thread Starter
2nd Gear
Joined: Jul 2010
Posts: 2
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ride height - autoslalom
I have an 87 that my son & I use for autoslalom. This is our first year. My car seems to have a lowered front and the rear seems high.
I measured to the frame at the jack points on both sides. The front is 5.5 inches from ground to frame. The rear is 6.5 inches.
I am guessing that for autoslalom I want the front and rear to sit at about the same height. Is this right or do I want some rake?
How can I tell if the front was lowered? I replaced bushings all around with polyurethane and the mounting points looked stock.
I measured to the frame at the jack points on both sides. The front is 5.5 inches from ground to frame. The rear is 6.5 inches.
I am guessing that for autoslalom I want the front and rear to sit at about the same height. Is this right or do I want some rake?
How can I tell if the front was lowered? I replaced bushings all around with polyurethane and the mounting points looked stock.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Stock ride height will show some forward rake; it's designed that way.
One thing you need to find out before making chassis modifications is whether or not such mods will place you in a different class. Some sanctioning bodies may not allow the changing of the ride height (lowering) or even using aftermarket suspension components like poly bushings.
Once you have decided on a class (i.e. stock versus modified) then you can begin to work on effective mods. Stiffer shocks, larger swaybars, even a specific alignment for autocross will go a long way to improved performance before working on ride height changes.
Vette Brakes has some good starting points for an autocross alignment. Check it out here Go to the "Alignment Specs" hotlink where you can download the sheet. They have specific alignments for the early C4's (84-87) for both "Advanced Street" and Autocross Baseline. I use the Advanced Street specs as I occasionally drive my 87 and also use it fro track days. The Advanced Street is a good comprise for what I do with the car. But if you intend to lower the car, do the alignment afterwards. Changing the ride height will affect alignment.
In the attached pic, you can easily see the stock rake on my 87. This pic was taken between two gates and the car is fairly stable at this point. Note where the black beltline trim piece is in relation to the front and rear tire sidewalls. The car has the Z52 suspension potion but I installed Z51 shocks, poly swaybar bushings on the stock size bars and stock size tires (older Hoosiers).
One thing you need to find out before making chassis modifications is whether or not such mods will place you in a different class. Some sanctioning bodies may not allow the changing of the ride height (lowering) or even using aftermarket suspension components like poly bushings.
Once you have decided on a class (i.e. stock versus modified) then you can begin to work on effective mods. Stiffer shocks, larger swaybars, even a specific alignment for autocross will go a long way to improved performance before working on ride height changes.
Vette Brakes has some good starting points for an autocross alignment. Check it out here Go to the "Alignment Specs" hotlink where you can download the sheet. They have specific alignments for the early C4's (84-87) for both "Advanced Street" and Autocross Baseline. I use the Advanced Street specs as I occasionally drive my 87 and also use it fro track days. The Advanced Street is a good comprise for what I do with the car. But if you intend to lower the car, do the alignment afterwards. Changing the ride height will affect alignment.
In the attached pic, you can easily see the stock rake on my 87. This pic was taken between two gates and the car is fairly stable at this point. Note where the black beltline trim piece is in relation to the front and rear tire sidewalls. The car has the Z52 suspension potion but I installed Z51 shocks, poly swaybar bushings on the stock size bars and stock size tires (older Hoosiers).
Thread Starter
2nd Gear
Joined: Jul 2010
Posts: 2
Likes: 0
My car also has the Z52 option. I am already in mod because the nose is lower than stock and I have a non-stock frame brace (mine was not with the car when I bought it). I am also using the advanced street settings. I have added 30 mm front sway bar and a 24 mm rear.
Looking at your picture my rear is about as high as your front under acceleration and going straight (I added a photo to my user info - don't know whether you can see it or not.)
Would stock ride height be in the shop manual?
Looking at your picture my rear is about as high as your front under acceleration and going straight (I added a photo to my user info - don't know whether you can see it or not.)
Would stock ride height be in the shop manual?
