front suspension sport shim, camber and toe settings

[GTSII]

The GEN II Viper front suspension features a set of "sport shims": remove these and you increase negative front camber by 1 degree, taking the car from a road to a track set-up. Reverse the operation, and you are ready to drive back home...

Of course, this will affect front toe, which must be reset after each removal or replacement of the sport shims.

My question is: does anyone actually do this? Or do you set the car up for the track, with something like 1.4 degree negative camber up front, and accept the uneven tire wear when not actually cornering the car hard (as in highway driving ro and from)???

And, if you actually do go through this procedure, what's your recepy for accurate front toe settings with minimal tools and hassle?

 

[GTSII]

no wisdom on this from anyone?

 

[GTS Dean]

Frankly, getting to the pivot bar bolts is a bit of a pain, but torquing them is even worse. Use a ratcheting box end wrench once they are reasonably loose, then the old 2-wrenches hooked together method for final tightening. Unless you cut holes in the top of your fender wells, there's no room for a torque wrench.

As for toe - you can pretty much leave it alone for the track after you have pulled the shims. You end up with something around 1/8" (3mm) +/- toe-out and that's just fine for the track.

 

[jcaspar1]

I can't take any credit for the following comments as I just collected them from my past few years on the board:
"Going to re-set toe in the front after taking out the sport shims and was wondering which way to turn the tie rod to bring the wheels in (increase toe in). After taking out the sport shims, I went from zero toe to about 1/4" toe out (wasn't expecting that much toe). My target is 1/8" max toe out (Gingerman - 1.8 mile tight roadcourse, relatively short straights, 115mph or so).

Looking into the wheel well it seems as though turning the tie rod Counter Clockwise screws the tie rod into the tie rod end, thus bringing the tires in.

Can anyone confirm? It would save me one trial and error step.

You are correct. For what it's worth, I've found that one complete 360 degree rotation on the tie rod will change your toe setting about 1/4". For Gingerman, above average amounts of toe out will help your corner entry significantly. I've run as much as 1/8" toe out on each front wheel at this track. This year I'll be using 1/16" on each front wheel. See you there."

and: "The additional toe-out is not intolerable, but you have to expect some additional twichiness at high speed on straights.
Last fall at TWS, I ran like 3/16" toe out in the front at up to 142 mph. Upon reflection, it was a bit much, but it sure helped get through the slow, twisty bits.
If you want, you can screw the toe link rods 1/2 turn clockwise to pull the tires in just a bit.
Viper-specific note:
All the toe links are right hand thread. Screwing them clockwise up front _decreases toe out_. Turning clockwise at the rear _increases toe out_ (NOT the hot setup).

P.S. - Tightening the nuts on the front pivot bar is much easier with a ratcheting box end wrench."

Try pulling them for the street first. I did and found the increased toe out caused a lot more tracking of the tires in road grooves. Should be less of a problem on the track. Good luck

 

[GTSII]

Thanks for the advice: now I'm curious to see if I will get small and reproducible toe out increase (decrease) when removing (replacing) the shims. If that is the case, as seems to be your experience, then it makes the whole thing much more interesting.

 

[VPRGTS]

Some info I had received:

When shims are taken out, tie rods should be threaded in 1.5 turns.

When shims are put in, tie rods are threaded out 1.5 turns.

This does not agree with some of the above info however.
If shim changes toe 1/8" and one rotation = 1/4", then 1.5 rotations is way too much.

Any more feedback would be appreciated.

 

[SoloIIRacer]

When shims are taken out, tie rods should be threaded in 1.5 turns.

When shims are put in, tie rods are threaded out 1.5 turns.

That is what we did on our 02 GTS last weekend for an autocross. The front was maxed out using the adjustments in the suspension, but it wasn't enough camber, so we pulled the shims. The car gained about 1 degree per side, and toed out quite a bit, I think it was over 1/2". We put 1.5 turns on each tie rod to bring it back to 0 total toe. We use paint to mark the street setting, then use a different color for the race setting, it works very well.

Jeff

 

[SoloIIRacer]

When shims are taken out, tie rods should be threaded in 1.5 turns.

When shims are put in, tie rods are threaded out 1.5 turns.

That is what we did on our 02 GTS last weekend for an autocross. The front was maxed out using the adjustments in the suspension, but it wasn't enough camber, so we pulled the shims. The car gained about 1 degree per side, and toed out quite a bit, I think it was over 1/2". We put 1.5 turns on each tie rod to bring it back to 0 total toe. We use paint to mark the street setting, then use a different color for the race setting, it works very well.

Jeff

 

[GTS Dean]

The toe change is not linear with the thread pitch.

 

[GTSII]

The toe change is not linear with the thread pitch.

hmmm... could you explain what you mean by that?