VetteDrmr

I'm replacing all four tie rod ends getting ready for the upcoming autox season (they're all sloppy), and need to get the car realigned. This car is our fun car for both me and my wife, so compromise settings are the order of the day.

I'm fairly comfortable with the camber settings I use (-0.8 front, -0.5 rear), and front and rear toe is set at 0. Tire wear on my autocross tires (RA-1s and V700s so far) is pretty even, requiring one flip during their lifespan.

The street tires tend to wear on the inside, but to an acceptable level. Again, I usually flip these one time before they wear out.

I got to wondering about the rear toe settings. What would be the impact of dialing in some rear toe-in? How does it affect tire wear? How much would be too much?

TIA, and have a good one,
Mike

jkonkle

front - toe out - think about when you walk, point your toes in and see how well you do.

rear - toe in

how much, depends....

The C6 alignment document from the C6 faq is gone, so I went to the way back machine and pulled this up:

alignment

2K3Z06

Kinda depends what you want to do. I would check the service perfered settings in the service manual.

I had my car with about 1/8 toe out, in front. Turned great on the autox, but would wander slightly at speeds above 100mph. You need a 1/16 or 1/8 toe in for the high speed stuff to be stable.

Specs say: +.04 in on front
+.08 total toe front

-.01 out on rear
-.02 out total toe rear.


I know if it's just slightly off. I can tell the difference. The thing just won't track straight, and gets the high speed weave.

When you barely turn the tie rods. (1 flat) it makes a big difference.

Just use a measuring tape and get it close, and take it over to Ruf. Bob has done a lot of corvettes.

cheers, robert

EvilBoffin

Here's some general info for you, Mike -

Advantages:
- Adding Rear Toe-IN will help maintain rear wheel traction when turning, and will resist rotation at the back of the car. It will allow you to get back on the throttle a little earlier as you exit a turn, and it makes the car feel more stable at speed.

- Adding Front Toe-OUT will improve initial turn-in and quicken steering response, which is very important in an autocross.


Disadvantages:
- Any tire that is not aimed dead straight (Zero toe) will be 'dragged' down the straights, and too much toe can actually scrub off straightline speed.

- It will wear your street tires more quickly.

- Adding too much front toe-out can induce mid-corner understeer, because the outside tire will be scrubbing badly and resisting the turn throughout the steady state part of the turn.

-----------------------------------------------------------
You're using pretty conservative camber settings, so I think the recommendations of 1/16" total toe per axle (front toe-out & rear toe-in, obviously) would be a nice, streetable compromise for you to try. I'm actually having Dave Farmer align my new Vette this weekend, and that's what I am going to shoot for, though I'm going to use more negative camber then you have.

BTW - I just purchased RA1's too, to use at both HPDE's and auto-x, at least initially.

Hope that helps...

davidfarmer

there is a little write-up on my site about FRONT toe, and why toe-out is important. I'm not as picky about the rear as some above.....I shoot for around 1/8" toe "in", but don't get too hung up on it.

http://www.davidfarmerstuff.com/Toe-Ackerman.pdf

VetteDrmr

Thanks for the info; that's exactly what I'm looking for.

Now, a question from a different perspective: What affects would 1/16" toe-out in front and 0-1/16" toe-in in the rear do to the cars street manners and street tire wear. My street tires are non-runflats on stock C5 wheels.

Thanks again, and have a good one,
Mike

0Randy@DRM

We run a little toe-in in the front of C5s and C6s. We try to get rid of the ackerman. Our reasoning behide this is, what good is a tire that is turning more then the other? Nothing besides scrubing speed and getting the tire hot. But all and all, either way can still win. Lap times and feel are the only way of really knowing.

The rear end is a little tricky. You really have to look at bushing deflection. Watch a rear tire on the dyno sometime. You can watch it move toe in to toe out during a run. This is very noticable on worn out stock bushings.

If the car has some power these are what we set them up to.

Stock bushing rear toe in about 1/4 inch total
poly bushing rear toe in about 1/8 inch total
Mono ball rear toe in about 1/16 inch total

Randy
www.dougrippie.com

VetteDrmr

Randy,

What if the car is basically stock? OE bushings, no engine/drivetrain mods, etc.

Thanks,
Mike

2K3Z06

The "big toe" debate.............LOL.

These guys know more than me, so i will be quiet.......

See ya at the track Mike.

0Randy@DRM

Mike,
Right about 1/8 total should work just fine.

Randy

VetteDrmr

Just to close the loop, thought I'd let you know what I did and my observations.

1. I decided to go with -0.7 front camber, -0.5 rear. Toe was set to 0.1" total toe out front, 0.1" total toe in rear.

Straightaway acceleration didn't seem to be affected, and the car felt like it had more stability in power-on sweepers. Also it seemed like I got rid of a bit of understeer on hard slow speed transitions.

Bottom line is that the car felt better than it has in the past. Oh, and as an added bonus I took my first FTD!

Thanks again for all the advice; it helped me a bunch!

Have a good one,
Mike

jonparks

Glad you found that page. I've been looking for that for almost a month now!