B&S Motorsports-----(Brian and Scott) got together last night to finally do some real auto-x alignment settings.
What we had been doing is setting our alignment for street driving, since both of our cars are our daily drivers, and just moving the camber plates in at the event. Big problem with this, obviously, is that we never knew how much toe out we were getting.
After reading some interesting post, I decided to go with the idea of setting the auto-x alignment FIRST, then going backwards to the street setting.
We found out some very useful info regarding toe change/camber changes, etc. While these numbers may not be completely useful "across the board", they will certainly give some of you a good idea of what to expect or at least a good starting point.
I do realize that my starting alignment numbers were quite screwie, but I'm giving them anyway for comparison sake.
Here are our numbers from start to finish.


Start:
---Camber----
FR. -1.0 FL. -1.3
RR. -.02 RL. -0.5

-----Toe------
FR. 0 FL. +1/8"
RR. 0 RL. 0

Camber plates on the 0 mark.

After finding -3.0 by adjusting the plates:
-----Toe------
FR. +5/16" FL. +4/16"

We then set the front toe, while at -3.0, to +1/8" TOTAL.
Brian determined by the change in toe that took place after moving the plates to -3.0 that we would get approx..... 1/8" toe change (PER WHEEL) per 1 degree of camber change. Also, as with the JIC's we used to have,,,,,,,,, each tic mark on the plate represents approx. 0.2 degree's in camber change.
Now...knowing that each tic is 0.2 and 1 degree of change should yeild 1/8" toe change, we simply moved the camber plates back 5 tics to -2.0 degrees which gave us a TOTAL of -1/8" for street driving.

For now...we left the rear the way it was...

Please discuss...I hope this info helps as I havent seen it layed out in this detail before on the board.

Scott....(with much help from Brian (Bridrive)

That was actually rather helpful. I'm trying to figure out how I'm going to go from my street setup of -1.5 front to an AutoX setup of -3.0 without screwing up my toe. (STi)

Your formula of "1/8" toe change (PER WHEEL) per 1 degree of camber change" was very informative. Many Thanks!!!

Truly

While I didnt point it out, we did re-measure everything to confirm the changes.

Doesn't the formula also depend on caster? How much caster do you have?

Doesn't the formula also depend on caster? How much caster do you have?

We havent measured caster. We are still stock in regards to not being able to change that.

This was intended as "general information". We do realize that it may not be exact for everyone, but could be used as a reference or a good starting point.

Just so everyone knows, we did this on my car, which is STX legal and rides at what I would consider a somewhat "standard" ride height. IIRC, it was approx. 14" center to fender in front and approx. 13.5" center to fender rear.
Brian can correct me if I'm wrong..His memory is usually better than mine. ;)

Coilovers are Tein HA's.

Scott

The sliding scale will also probably be effected to some degree by the front rideheight.
Scott and I are both at between 13 15/16" and 14" fender to wheel center up front...with a little deviation from corner balance at this height.

His car is now set up for this: At a full -3 degrees camber(front) he has a combined front toe of 1/8"...(1/16" toe out per side) not bad at all...considering where it was.

On the street, his car will run -2 dgrees camber (front) and this brought the front combined toe to -1/8"...(1/16" toe IN per side)...

With his plates and our base setup on that car, he can actually go all the way to over -3.5 degrees, however, with the spring he's running up front (10kg/mm) and a 22/23 mm bar, he will probably not need max camber anywhere...

Now, if only there was an "accurate" way to make consistent rear toe changes ON Site at a venue.

BTW, his Toe numbers are with 17" hoops.

BriDrive

Now, if only there was an "accurate" way to make consistent rear toe changes ON Site at a venue.


I picked up one of these a couple years ago for doing alignments

http://www.racerpartswholesale.com/images/9110a.jpg

Then, this winter I built a replica (minus bubble gauge) out of angle aluminum to mount on the other side so I'd have an easy and accurate way of measuring toe.

If you just wanted to build a toe gauge, you could simply take a couple measurements on your wheel, pick up some angle stock, measure, cut, measure, attach (rivits if aluminum, weld if steel), measure, notch and you've got yourself a super cheap toe gauge. Basically, form it to an upside down "T" with a bolt through the upright to sit rest against the top lip of the wheel and two bolts through the cross part for the lower side of the wheel. You could leave the cross part completely straight and it should be low enough that the tape measure will clear the underside of the body. Make some corresponding notches on both cross pieces and you've got yourself a pretty accurate toe gauge.

Err...yeah...I should have mentioned we have fab'd this kinda a gear already...in a different form of course....it's not hard to make "combined toe" changes to either car (WRX sedans)...the toe bolts just aren't precise enough that we wouldn't want to realign the car again after returning home again. The front's are now not an issue.

It wouldb be nice, but too much $$$ would be to throw on adjustable lateral links a la JIC or Cusco or the like.............

I just want ultra-ease and ultra accuracy...neither of us want to dink around with toe settings in parking lots/paddocks and then dinking around again before we jump in and go home...

BriDrive

I have similar data here but toe is in degrees and it is with stock STi caster.

Toe vs camber (http://forums.nasioc.com/forums/showthread.php?t=649111&highlight=jic)

I think the way you have it is *perfect*. Slight toe in for the street to make the car tramline less and be a little more stable on the highway and then good camber for autox as well as a little front toe out to help with the turn in. Nice!

I myself have always run 0 toe in the front and "slight" ;) rear toe out. At the Pro, I went from our -2.75 camber, 0 toe setup, to -3.25 camber and didn't touch the toe, so I'm assuming I was 1/8" toe out or so (I'm running more caster then you, so more toe change per camber change). I *really* liked the way 1/8" toe out felt in the front and will try to talk biggly into running that from now on :)

-Tom