chuck1026

What kind of tire wear issues will I have versus improvements in handling from switching to aggressive alignment settings? I am thinking of using V&P's "Advanced Street" settings from http://www.vbandp.com/instructions/h...ruct/align.htm

Front:

• Toe 0" to 1/32" in
• Camber 1/4° neg
• Caster 6-7° pos

Rear:

• Toe 1/16" in
• Camber 1/2° neg

I have read toe affects tire wear more so then camber, but would appreciate some real world feedback. I have new Goodyear F1 Supercar EMT's. I want to take advantage of their improved grip w/o grinding them down in 5K miles of driving.

Thanks!

Chuck

TedDBere

If you're just driving it around on the street then I don't know why you'd put any toe into the car. And I'm not sure why you'd put more camber in the rear than the front. Just stick with the stock settings if wear is your concern. IMHO

1999 C5 Coupe

Chuck I have similiar numbers on my coupe for toe and castor. Camber is around 1.2 front and 1 rear. I have yet to notice any adverse wear from these settings. (Over a year on current tires) My car is a dd and occasional autocrosser. The slightly more aggressive alignment was well worth it IMO.

AU N EGL

is that one-quarter Negative degree?

Normal is -1.0* camber.

Agressive street is -2.0*
Max but equal caster.
toe OUT 1/16" or neutral,

never tow IN.


Rear

-1.0* camber
1/16* toe in

No ranges must be exact.

chuck1026

So you have 1.2 degrees of camber front and 1.0 degrees of camber on the rear? What about toe and caster?

I like to push my car on the street (apex corners, etc) so I definitely want a more aggressive setup - as long as I am not going to be buying tires too often .

1999 C5 Coupe

Correct on the camber numbers. I can't recall the exact number on the castor but it is somewhere in the range you mentioned in your initial post. Zero toe in the front and 1/16" in on the rear. The zero toe setting seems to help it turn in a lot better. It does tend to hunt and wander a little more on the road with zero toe but the turn in response is worth it to me. Slight toe in in the rear seems to help keep the rear planted under acceleration.

I think you are safe regarding tire wear if you stay close to those VBP specs. I haven't noticed anything bad running a bit more camber like I have though.

chuck1026

Maybe I will go with just a *touch* of toe (in or out? Which is correct?) for the front and set camber at -1.0 front and rear...

DOUG @ ECS

I was reading that thinking "toe in?"

gkmccready

"Push the car" != "not buying tires too often"

Doesn't matter what alignment you pick.

If you go with an aggressive alignment, but mostly cruise down the road, you'll prematurely wear the tires. If you go with a waxer alignment, but push the car hard, you'll prematurely wear the tires.

You're going to have to experiment with what works for you and how much tire wear you're willing to deal with.

FWIW, on my C6 Z51 I have:

Front:
-1.1deg
slight toe-out
7.5deg castor (I'm going to try less soon!)

Rear:
-0.9deg
slight toe-in

I have 9500 miles total on the car and tires. That includes 21 twenty minute sessions at Thunderhill, four or five 5 run autocrosses, and the rest are street miles. I am known to be easy on tires and equipment, mind you...

chuck1026

Let me try to clarify...

I don't put many miles on my C5. It sees between 1,000 and 2,000 miles per year on average.

When I drive it, I like to enjoy it's great handling. I want an alignment that will help me wear the tires evenly... figuring on 25% to 30% of "spirited driving".

That's why I was thinking of using my originally posted settings... but I think there is a wealth of experience with settings /driving habits and resulting tread wear in here.

AU N EGL

Talking it easy is fine, but you original alignemts will ware out the tires too soon. Never toe IN, 1/4* camber will ware out the inside of the tread before the out side.

But if you one drive 1-2,000 miles a year, the tires grip capabilties will be gone in two years. Tread depth has nothing to do with grip. Tread is to remove wated from under the tire in rain. Tire life of an R compound is 18-24 maybe 30 months max, even it they are just sitting.

The tires have chemicals in the rubber that help with grip. These chemicals leach out within 12-24 months

robvuk

If you only drive 1000 miles per year. Tires will dry rot first. Put any alignment on it you want and enjoy.

Bill Dearborn

Actually you are choosing close to a stock alignment. Most people run a lot more aggressive than that. Here are the factory recommendations. I didn't include the tolerance only service preferred numbers. My numbers are a lot more aggressive than these except for toe in. To keep wander down while driving on the highway I go with just a bit of toe in (similar to what you have chosen). I give up a little turn in at the track or an autocross but I don't have to worry about the car tracking all over the place when I am driving down the highway.

Wheel Alignment Specifications
RPO Operation Service Preferred

All Front Individual Toe + 0.04
All Front Sum Toe + 0.08
All Steering Wheel Angle 0.0
FE1 & FE3 Front Individual Caster + 7.4
FE1 & FE3 Front Cross Caster Within +/- 0.5
FE1 & FE3 Front Individual Camber - 0.20
FE1 & FE3 Front Cross Camber Within +/-0.5
FE4 (Z06) Front Individual Caster + 6.9
FE4 (Z06) Front Cross Caster Within +/- 0.5
FE4 (Z06) Front Individual Camber - 0.70
FE4 (Z06) Front Cross Camber Within +/- 0.5

All Rear Individual Toe - 0.01
All Rear Sum Toe - 0.02
All Rear Thrust Angle 0.0
FE1 & FE3 Rear Individual Camber - 0.18
FE1 & FE3 Rear Cross Camber Within +/- 0.5
FE4 (Z06) Rear Individual Camber - 0.68
FE4 (Z06) Rear Cross Camber Within +/- 0.5



Bill

bobmoore2

Damn! You really should put more miles on it, just to keep it running right.

When you're ready to sell the car, give me a call.

chuck1026

Thanks for the advice Bill. Do you think the C6 run flats will roll and wear evenly with decent cornering with the C5 Z06 camber settings (-0.5, or even -0.7)?

Don't hold your breath. My C5 is my toy, and it ain't going anywhere (Automotive Gods permitting). The mileage is low mainly because the weather in CNY stinks. Heck, it is snowing here as I type this .

ErnieN85

Some high points for you, with the miles you drive you will need to replace the tire before they wear out (dry rot). With runflats straight up (no camber) is the only way they will wear right! If you want performance ditch the run flats, go to an agressive aligmment and replace the tires when they wear out, just plain don't worry about un even wear as the number of mile you drive they will last longer than the stickyness will!

chuck1026

My 6 year old 12,900 mile stockers are not dry rotted, but they have all worn very evenly. I am assuming the stock specs were ok.

I am curious if a touch more negative camber would be ok... with minimum (just a bit of) toe... thinking the answer is yes.

ErnieN85

Chuck, sorry about the dry rot thing, actually it's just that the rubber gets hard and doesn't really work well for grip. Yes you can increase camber for better cornering although if yours are wearing evenly you probably have a good setting for the way you drive. As to toe it seems to have greater effect on wear than camber with toe out producing wear on the inside edges. now that said the runflats have a much lesser amount of sidewall flex and therefore seem to be much more sensitive to wear with increased camber.
many of us who track our cars run from 1-3 degrees of camber on the front. this much would be real bad for runflats

Bill Dearborn

It depends on how much wear you can stand on the inside edges. When I first got my 97 I went through EMT tires in about 7K miles per set (even had the first set of rear tires replaced under warranty). But I was autocrossing and tracking the car besides driving on the highway. At one time I had over 2 degrees of negative camber in the front. I finally settled on -.7 all around (this was before the Z06 came out) and got decent for me tire wear.

Bill

robvuk

If the tires are not showing more wear on the outside shoulders then the alignment you already have is just fine. On the dry rot issue, no you will not see it but you can certainly feel that they don't grip like they used to.