C4 alignment numbers
Thread Starter
Racer
Joined: Dec 2008
Posts: 327
Likes: 0
C4 alignment numbers
I have an '87 that gets used for around town driving and autox in near stock condition. I'm running 285/18"fr 315/19" for street, and 17"/18" hoosier A6 for autox. I"m looking for suggestions for alignment numbers. I want the best performance I can get without killing my street tires. What are others running?
Team Owner
Joined: Mar 2001
Posts: 30,858
Likes: 293
From: Boston, Dallas, Detroit, SoCal, back to Boston MA
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
I'm using the VB&P "Advanced Street" specs for my 87 coupe. I run 275/40-17 A6's on all 4 corners. Still see a little understeer on tight turns on short and slow a-x courses but sometimes changing front tire pressures help. But so would changing my driving style when it comes to corner entry 
I do occasional track days with the car and the Advanced Street settings seem to work for me with my Kumho Escta MX's. I don't push the car real hard but it does feel solid.
My 87 is a Z52 car so it has the base springs but I've added poly sway bar bushings and Z51-specific Bilsteins to help with lean. I drive the car on the street on occasion and the Advanced Street settings don't seem to hurt my street tires and the car is not "darty" at all. Tire wear is even and that's a good sign.
If your car has the Z51 suspension, you will be able to get more negative camber up front because of the OEM offset lower control arm bushings but the more negative camber you have will probably be at the expense of tire wear and easy street driving. Zero toe-in works fine for the front but stay with just a bit of positive toe out back.
I do occasional track days with the car and the Advanced Street settings seem to work for me with my Kumho Escta MX's. I don't push the car real hard but it does feel solid.
My 87 is a Z52 car so it has the base springs but I've added poly sway bar bushings and Z51-specific Bilsteins to help with lean. I drive the car on the street on occasion and the Advanced Street settings don't seem to hurt my street tires and the car is not "darty" at all. Tire wear is even and that's a good sign.
If your car has the Z51 suspension, you will be able to get more negative camber up front because of the OEM offset lower control arm bushings but the more negative camber you have will probably be at the expense of tire wear and easy street driving. Zero toe-in works fine for the front but stay with just a bit of positive toe out back.
Melting Slicks
Joined: Aug 2004
Posts: 3,003
Likes: 89
From: Indy IN
C4's seem to work best with a square setup. Putting bigger tires on the back is the easiest way to make a C4 push like a pig... We put the V710's from my Z (17/18) onto our BSP car and that was a waste of time...
Race Director
Joined: Jun 2004
Posts: 13,963
Likes: 709
From: WI
I tried the advanced street at first and quickly thought it was to tame. I'm running 1.5° in the front and 1° in the rear now. The grip level feels more solid throughout the entire corner arc. I stick to street tires still and there was more to be had but we stopped there. All the shims are removed though.
Burning Brakes
Joined: Sep 2004
Posts: 1,181
Likes: 1
From: Manchester NH
Nuetral toe in the front is nice on the street and it's easy enough to dial in a bit of toe out @ the a/x, then change it back for the ride home. Keep a little toe in out back to keep the rear stable.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Le Mans Master
Joined: Oct 2007
Posts: 9,702
Likes: 3,472
From: Akron Ohio
2025 Corvette of the Year Finalist - Modified
2024 C5 of the Year Winner - Modified
2023 C5 of the Year Finalist - Modified
2022 C5 of the Year Finalist - Modified
St. Jude Donor '09-'10-'11
I agree.
This probably isnt the most ideal case but I had an alignment shop I knew play with shims and settings for me one afternoon. My car is setup for street and roadrace. For race they removed all the shims and I have just over -2* chamber front and about 1/16" total toe out. I had them add shims until the toe was zero and i got about -1.8* front chamber. This way I dont worry eating tires on the street and come race day I pull the shims and have my race setup. Its simple enough to do while changing to race tires and race brakes. The rear is always the same with -1* chamber and 1/8" total toe in.
This probably isnt the most ideal case but I had an alignment shop I knew play with shims and settings for me one afternoon. My car is setup for street and roadrace. For race they removed all the shims and I have just over -2* chamber front and about 1/16" total toe out. I had them add shims until the toe was zero and i got about -1.8* front chamber. This way I dont worry eating tires on the street and come race day I pull the shims and have my race setup. Its simple enough to do while changing to race tires and race brakes. The rear is always the same with -1* chamber and 1/8" total toe in.
