Need Some Help with Alignment Specs
Safety Car
Joined: Nov 2009
Posts: 3,973
Likes: 341
From: Adelaide South Australia
I just finished rebuilding the front suspension and steering rack on my 85. I did the rebuild because the car wandered and pulled on uneven surfaces. Over the last 5 years my tires had worn perfectly. I installed new poly bushings, ball joints, tie rods and had the steering rack rebuilt by Turn One. I did not replace the upper control arm bushings. They looked to be OK and I didn't want to deal with pressing new bushings in.
I had a local shop do the alignment. The Tech checked caster and camber and left them as is. He adjusted the toe.
Actual LF Camber -0.1 Factory +0.3 to +1.3
Actual RF Camber -0.2
Actual LF Caster +4.9 Factory +2.3 to +3.8
Actual RF Caster +4.7
Actual LF Toe -0.01 Factory -0.10 to +0.10
Actual RF Toe +0.01
I'm curious what others are setting caster and camber to. Should I go with positive camber like the factory specs? And do I need to reduce caster? By the way, this is a street car that I may do some autocross with.
I had a local shop do the alignment. The Tech checked caster and camber and left them as is. He adjusted the toe.
Actual LF Camber -0.1 Factory +0.3 to +1.3
Actual RF Camber -0.2
Actual LF Caster +4.9 Factory +2.3 to +3.8
Actual RF Caster +4.7
Actual LF Toe -0.01 Factory -0.10 to +0.10
Actual RF Toe +0.01
I'm curious what others are setting caster and camber to. Should I go with positive camber like the factory specs? And do I need to reduce caster? By the way, this is a street car that I may do some autocross with.
FL Camber -1.2
FR Camber -1.1
FL Caster +3.7
FR Caster +5.1
F Toe +0.2 mm
RL Camber -1.1
RR Camber -0.9
Rear Toe +0.8
this combo works well on mine, and hasnt chewed out the tyres yet (not a daily driver !)
Last edited by blackozvet; Jul 1, 2013 at 07:47 AM. Reason: finish
Team Owner
Joined: Sep 2001
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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Melting Slicks
Joined: Jun 2013
Posts: 3,065
Likes: 39
Sorry, Daniel, but I can't agree with this analysis. Changing the caster in a Corvette won't affect the angle of the shock. Negative caster will cause the car to wander, and the steering wheel won't return to center on its own. The +5 degrees caster recommended by several people is an excellent suggestion.
If you want to test this negative caster idea, try backing up fast, turn the steering wheel a bit, then take your hands off the wheel! (Be ready to step on the brakes!!)
If you want to test this negative caster idea, try backing up fast, turn the steering wheel a bit, then take your hands off the wheel! (Be ready to step on the brakes!!)
Safety Car
Joined: Jun 2003
Posts: 4,250
Likes: 656
From: San Diego Ca
My basic parameter for any performance alignment on any car is a tad of toe out for turn in (1/16th), Negative Camber to taste (RRing -2-3 deg if you can get it) and positive caster in the 5-6 range if you can get it. Many cars are limited on caster once neg camber is dialed in. On an autox I like rear toe about a 16th or 8th out. On a track I like rear toe neutral or a 16th in.
For a street car zero toe, neutral camber, and 5 positive caster will generally work on any rear drive car. On a 4 wheel alignment neutral toe and camber on the rear also.
Negative camber will wear out the inside of the front tires when you are street driving so be careful. I generally limit street driven cars to 0.8 negative camber or so and that is only if you actively autox. Many will also add their desired autox toe out by moving the tie rod a couple of flats when they arrive at the event.
Adjust from there for taste.
For a street car zero toe, neutral camber, and 5 positive caster will generally work on any rear drive car. On a 4 wheel alignment neutral toe and camber on the rear also.
Negative camber will wear out the inside of the front tires when you are street driving so be careful. I generally limit street driven cars to 0.8 negative camber or so and that is only if you actively autox. Many will also add their desired autox toe out by moving the tie rod a couple of flats when they arrive at the event.
Adjust from there for taste.
Last edited by pkincy; Jul 1, 2013 at 11:14 AM.
Melting Slicks
Joined: Jul 2005
Posts: 2,649
Likes: 863
IMHO - there is no right or wrong alignment spec. It's all a big compromise. As other posts have pointed out, what you plan to do with the car drives the train. More neg camber will improve your autocross times, but at the expense of tire wear and the car wanting to follow the "ruts" that seem to be everpresent in our highway system. In my experience - it's hard to get a stock C4 past about 1.5 degrees neg camber - but if one were to "thin down" the factory control arm "spacers" you can find a bit more than that. Normal street driven cars are typically set up with a bit of toe in - this helps prevent toe out when the steering system develops a bit of slop. Toe out is commonly used on race cars, and makes the car want to turn in - including when you're driving down a straightaway (read that as toe out induces some instability - great for Road Atlanta, not great of I-95). You really don't want any rear toe out - some experienced road racers use it, but it can make for attention getting moments......
Remember - on a C4 - camber adjustment changes toe, meaning toe is ALWAYS adjusted last!!!
My "recommendation" for a nice street ride that occasionally gets to an autocross would be to start with about half a degree neg camber, and about 1/16 - 1/32 of total toe in. See how it feels and how the car drives. You can easily add some more neg camber - but tire weat will increase.
Remember - on a C4 - camber adjustment changes toe, meaning toe is ALWAYS adjusted last!!!
My "recommendation" for a nice street ride that occasionally gets to an autocross would be to start with about half a degree neg camber, and about 1/16 - 1/32 of total toe in. See how it feels and how the car drives. You can easily add some more neg camber - but tire weat will increase.
Team Owner
Joined: Sep 2003
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From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
FWIW
Just got a new set of Kumho XS's and needed to check/reset alignment
Camber -0.5 Front -0.6 Rear
Toe (in) 0.10 Front 0.23 Rear
Caster 6.2 Pos
Thrust 0.02
*All numbers are in degrees
Just got a new set of Kumho XS's and needed to check/reset alignment
Camber -0.5 Front -0.6 Rear
Toe (in) 0.10 Front 0.23 Rear
Caster 6.2 Pos
Thrust 0.02
*All numbers are in degrees
