Alignment Help Thread

[tero.k]

Hi Pete,
I got Airlift and setted very low for my daily driving
my tires are 22" 255/30 and 285/25
what you recommend wheel alignment?
how much is lowered is hard to say but i´d say 2" drop
For daily driving only

-Tero

[JusticePete]

Your set up is a prescription for rear inner shoulder rear tire wear so we want to minimize it.

Make sure your alignment tech sets the toe bolts to nuetral, the eccentrics not touching the fences. Then set the rear camber to the least negative value. Have him set the rear toe IN to -0.08 per side. We are using less toe, because as you increase toe you will also increase negative camber.

Up front -0.75 camber and 0.00 toe.

Enjoy your setup.

[mcynet]

I have a buddy that works at firestone and he has been helping me trying to get my alignment set the best it can be for autocross without trashing my tires when I drive to and from events.

This weekend I think we hit the edge of what my car adjust to stock. I wanted to find out what settings you guys are using. Do my settings look solid?

My settings:

FRONT: left and right
CASTER 5.6
CAMBER -1.9
TOE -0.01

REAR
Caster He said we couldn't change
CAMBER -1.0
TOE -0.01

any help you guys can provide would be great. Im using Hankook S3 R222 285/35/20s on factory rims.

Thanks

[JusticePete]

Tell your buddy to set the toe eccentrics to a neutral position, the eccentrics not touching the fences. He will then be able to set camber. As he adjusts the camber will change, but he should be able to get a better split.

[mcynet]

What settings do you recomend? or is this good?

This shows where im at, with me sitting in the car.

[Rob@WretchedMS]

are you setting this up for:
1. Street Use Mostly, with some AutoX, so tire wear is important
2. Good Blend of Street/AutoX, tire wear is not as important
3. Primarily setup for AutoX, don't care about tire wear at all.

[mcynet]

Originally Posted by Rob@WretchedMS

are you setting this up for:
1. Street Use Mostly, with some AutoX, so tire wear is important
2. Good Blend of Street/AutoX, tire wear is not as important
3. Primarily setup for AutoX, don't care about tire wear at all.

2, I only drive on weekends and I autocross 2 times a month. I want my tires to last but I don't expect to get more than a year out of them.

[JusticePete]

Minimize the camber with -0.50 being the target. Rear toe should be set IN 0.12 per side.

[mcynet]

Originally Posted by JusticePete

Minimize the camber with -0.50 being the target. Rear toe should be set IN 0.12 per side.

I am not an expert just trying to understand the effects on the car.

Its my understanding if i drop the camber to -0.50 i will lose cornering performance on the autocross course. Every one says the more the better when your driving hard in the corner.

Also my rear toe is -0.01 what is the reasoning to make it positive. 0.12?

Just trying to understand, so I can be better educated.

Thanks

[Norm Peterson]

Toe-in for the rear wheels is the more stable arrangement - you don't need or want the rear end of a RWD car to get too twitchy, as that sometimes ends up with the rear deciding that it wants to take a turn at leading the parade (especially on drop-throttle a couple of cones in on a slalom with decreasing cone spacing that you entered a bit too hot).

FWIW, in FWD cars, rear toe out is one way of tricking these much more heavily understeerish cars into more responsive cornering at autocross.

What you do with rear camber is a compromise between maximizing midcorner grip (when the car is rolled over), tire grip for accelerating off the corners (car still rolled over somewhat), and the car's understeer/oversteer balance. Ideally, you'd have one set of specs for your street driving and another (possibly "looser") set for your competition time, but given what it takes to set the rear alignment specs on this chassis that's probably not a reasonable option.

It appears to me that Pete's -0.5° rear camber spec is mainly intended for the non-1LE SS, which has heavier understeer and relatively more rear grip in reserve than it needs. In that situation, you've got a little extra rear grip that can be sacrificed to gain a less understeerish handling balance, and you wouldn't necessarily be losing ultimate cornering g's because you weren't able to access all that extra rear cornering grip anyway.

I suspect that the 1LE with its lighter understeer might do better with rear camber slightly more negative. If you've done any suspension modification or made any tire or wheel/tire changes for autocross, you'll have to let the car tell you what it wants.


Norm

[mcynet]

Thanks that's a great way to explain it. Ill put her back on the rack and make the toe a little positive in the rear.

BTW no suspension work she's bone sock.

[CamaroSS sleeper]

mcynet

I believe "justicePete" meant to say -0.12 as he said toe "IN" per side.
a positive toe 0.12 "OUT" will yield some really unpredicatable ride.

This is based on my own experience.

[Norm Peterson]

I'm pretty sure that the usual convention for toe is positive = in / negative = out.

Pfadt did use negative fractions of an inch to indicate front and rear toe-in but the toe angles were still given as positive. There was a specific note about this in their alignment suggestion sheet, which usually means there's an important difference from what's usual. The link to video in the following quote goes back to a page on Hunter Engineering's (the alignment people) site.

Link to video
Sign convention
Positive Toe is the leading edge of the wheels closer together.
Negative Toe is the leading edge of the wheels further apart.

Norm

[JusticePete]

Because we are on a forum with enthusiasts who are not all skilled professionals I try to avoid confusion with toe in terms of positive or negative and list them as IN or OUT. In the future, I'll try to remember to post this illustration from my Facebook Alignment Gallery too.

Norm, There is so much more grip in the 5th Gen IRS than the front Strut / Virtual Pivot even the 1LE and Z/28 respond to less rear negative camber than one would expect.