Autocross Alignment

[Trailertrash]

My second auto cross event is this weekend. Just put on a new set of Hoosier A6 tires and did a moderate track alignment.
Front
Camber -1.9
Caster 6.0
Toe out 1/32 per side

Rear
Camber -1.3
Toe IN 1/16 per side
Did some testing at a local parking lot and what a differance!! I have always had new street tires and ran them to death. And occasional used slicks. Never did a track alignment before either. Now that I have the slicks and the alignment its like a totaly differant car. Now its time for a real set of seat belts as my cornering G's just went way up.
The viper is one awsome machine. Hope to wip up on a few corvettes Sat and Sun.

 

[jay01m]

I'm not an alignment expert, but have been told that for auto-x you want as much caster as you can get. Not sure if that's true or not though.

 

[GTS Dean]

More rear toe-in is a good thing.

Have fun!

 

[Trailertrash]

I took second place behind the winning time by 1.3 seconds but I was voted the top novice driver and won a SCCA membership for next year. I would like to improve on the current alignment settings I have more for autocross only not as a street car. I feel the car is handling very well but the A6's give up alot once hot. Any tricks to tighten the car up all the way around?

 

[mjorgensen Woodhouse]

With a lot of static negative camber in the front you don't need a ton of caster, all that does is slow turn in grip and lessen braking effectiveness. You are OK with 1.5-1.9 in front with 4.5 - 6 degrees of caster. The rear I would put more rubber flat on the ground by reducing the camber to .7 - .9 max negative. The rear toe should be fine where you have it. The front if it is darty actually makes the Viper harder to drive because you feel as though you are chasing the rear all the time. You may be better off dialing that back to 0 so the car is better under fast braking and turn in at an autocross.

 

[escapedan]

Good points Mark (thanks again for the call regarding the brakes the other day - sorry we missed each other.

I use 2 degrees negative camber in front and rear with some pretty aggressive toe out up front and slight toe in in the rear (also on A6s). The turn-in for autocross is outstanding and I am able to keep the rubber on the ground without wheelspin. I have ~40 runs (not days) on the A6's and will be rotating them after the next event.

That setup on the track is down right sketchy. At much higher speeds the toe out makes it very darty. Good luck, I'm always happy to hear about another autocrossing Viper!

 

[escapedan]

Oh, if you are ok going into ASP (vs. SS) get yourself a good set of shocks - I suggest Moton. You think the car handles good now....you ain't felt nothin' yet.

 

[1TONY1]

I'll just take good tires, remove the sport shims...a **** load of power and lets get it on

 

[Trailertrash]

Thanks for all the positive feed back. In autocross our speeds are low, the car is very stable until until the 4th time out where the slicks are to hot and I start to push through the corner. The rear grip seems fine unless I over power the turn out. I'll try -2 camber up front and leave the rear alone. I have been running 33psi all the way around and I no I need a pyrometer to check tire temps I'll get there. Tread wear is even for now. Should I spray the tires down with water between rounds?

 

[02rt10]

did you do the alignment yourself?

 

[Trailertrash]

yes it nots difficult if you take your time with good equipment. A well calibrated Hunter machine is what I use

 

[1TONY1]

Thanks for all the positive feed back. In autocross our speeds are low, the car is very stable until until the 4th time out where the slicks are to hot and I start to push through the corner. The rear grip seems fine unless I over power the turn out. I'll try -2 camber up front and leave the rear alone. I have been running 33psi all the way around and I no I need a pyrometer to check tire temps I'll get there. Tread wear is even for now. Should I spray the tires down with water between rounds?

Your tire pressure is too high.
Start at 26 and go down from there. I know what everyone at the autocross will tell you but I don't care what the norm is for the little tire guys...they can run their 45 and 50 psi all day long.

 

[Madduc]

Thread jack...hey Tony, what would you recommend for rear tire pressure using BFG R1's on my ROE'd (695rwhp) aggressive street driving??

 

[1TONY1]

Thread jack...hey Tony, what would you recommend for rear tire pressure using BFG R1's on my ROE'd (695rwhp) aggressive street driving??

I'd stay with the factory specs on the door.