Hello,

I'm considering buying a set of Z07 rims (18x11 and 18x9.5) for my C5 coupe, and would like to lower the car maybe 3/4" or so, but not more. I've read that lowering the car will cause excess wear on the inner treads unless you re-align to the stock camber settings. My question is, going with the wider tires, should I set this to the Z06 settings or just the stock C5? Will it make much of a difference which? I plan on keeping the stock C5 suspension components, at least for now.
Any thoughts would be greatly appreciated.
Cheers
Jason

 

Based on what many have said in the past, if you're going to use run-flat tires, stay close to the OE coupe and convertible alignment specs. If you're going to run non-RFs, go with the Z-06 specs.

 

I'm all the way down on stock bolts with 18's all around. I run the Z06 specs but with only 5 degrees of camber on the front. It's a little easier on the insides of the front tires.

 

I'm with leadfoot. Runflats are very stiff and don't like much camber. You'll get excessive wear inside.

Non-runflats are much more forgiving.

Camber isn't nearly as hard on tires as toe. If you are running non-runflats and stock toe settings, going to Z06 camber settings should be fine and will give you just a bit more contact patch in corners (if this is of concern).

I'm running -1.5F, -1.0R with a fair amount of toe (out F, in R, I forget how much) and I don't see wear being too bad. There's some, but I track, and the handling is worth the street wear to me. Depending on the tires you run, you could always slide them to the other side after some number of miles.

I think you meant caster (I'm guessing a typo) and WOW that's pretty low... What's your high speed stability like?

 

For what it's worth, 5 degress of CAMBER would have you driving on the sidewalls! And yes, IIRC the factory settings call for 6.5-7 degrees of caster.

 

I just lowered my 98' all the way on the stock bolts and I run factory sized wheel/tires using non-runflats. My car is pretty stock and it is mostly driven on the street. Can somebody give me full alignment specs that I should go with? This way I can write them down and take them to the alignment shop. Spell it all out please because I know nothing about alignment.

Thanks!
Zack

 

OOPS! I did mean caster. Not paying attention.

 

Zbrink, I found the following alignment data from the forum, I hope this helps....the first set of data appears to be for a stock C5, and the second set is for the various suspension options (including Z06 specs)...hopefully someone can validate this.
Cheers
Jason

--------------------------------------------
Stock C5:

Front Individual Toe: +0.04 degree +/- 0.10 degree
Front Sum Toe: +0.08 degree +/- 0.20 degree
Front Individual Caster: +7.4 degree +/- 0.50 degree
Front Cross Caster: within +/- 0.50 degree
Front Individual Camber: -0.20 degree +/-0.50 degree
Front Cross Camber: within +/-0.50 degree
Rear Individual Toe: -0.01 degree +/- 0.10 degree
Rear Sum Toe: -0.02 degree +/- 0.20 degree
Rear Individual Camber: -0.18 degree +/- 0.50 degree
Rear Cross Camber: within +/- 0.50 degree




===================================

Wheel Alignment Specifications
RPO
Operation
Service Preferred
Tolerance

Front Alignment Specifications

All
Front Individual Toe
+ 0.04
+/- 0.10

All
Front Sum Toe
+ 0.08
+/- 0.20

All
Steering Wheel Angle
0.0
+/- 1.0

FE1 & FE3
Front Individual Caster
+ 7.4
+/- 0.5

FE1 & FE3
Front Cross Caster
Within +/- 0.5
--

FE1 & FE3
Front Individual Camber
- 0.20
+/- 0.5

FE1 & FE3
Front Cross Camber
Within +/-0.5
--

FE4 (Z06)
Front Individual Caster
+ 6.9
+/- 0.5

FE4 (Z06)
Front Cross Caster
Within +/- 0.5
--

FE4 (Z06)
Front Individual Camber
- 0.70
+/- 0.5

FE4 (Z06)
Front Cross Camber
Within +/- 0.5
--

Rear Alignment Specifications

All
Rear Individual Toe
- 0.01
+/- 0.10

All
Rear Sum Toe
- 0.02
+/- 0.20

All
Rear Thrust Angle
0.0
+/- 0.10

FE1 & FE3
Rear Individual Camber
- 0.18
+/- 0.5

FE1 & FE3
Rear Cross Camber
Within +/- 0.5
--

FE4 (Z06)
Rear Individual Camber
- 0.68
+/- 0.5

FE4 (Z06)
Rear Cross Camber
Within +/- 0.5
--