How much 60' reduction can be expected, or does it really not help too much till you get some real power. My best 60' is in my sig, you think it would help very much?

 

I went from a stock TA with a urethane bushing to an adjustable stock mount TA from Spohn. I adjusted the pinion angle to 2 deg. negative and did not improve at all from a previous best of 1.60. Now I put it on towards the end of the season when the track wasn't prepped too well. Also I think I'm overpowering the BFG DRs now (275 17s) and it might be time for some 15s with some sidewall to flex and help the launch.

The Spohn is a beefy piece and Steve and Gordon are very good guys to deal with (I live 1 hour from them). I recommend it, but I'll hafta get back with you next season to see if it really helped improve my 60s. It did make the car more consistent, however, I just didn't lose any time off my 60'.
--Alan

 

The reason you probably didn't notice any difference is that the stock torque arm is set to ~-2.0/2.2 degrees. 0 degrees would give great traction, however, unless you have a beefy rear end AND suspension, (like a race car) don't do it. -1 degree is plenty for street and frequent strip use. I have my at about -1.75/1.8 degrees and it cut my 60 foot from a constant 2.3 to a constant 2.1. two tenths improvement on really crappy nearly bald tires. I think that was pretty good. You can really feel it plant the rear end under hard acceleration. and the transition between gears is MUCH faster and the power lost when shifting has all but dissapeared, as soon as it shifts, the power is INSTANTLY at the ground. I love it.

 

Two degrees negative sounds about right to me

 

I keep mine at -2, and like has been said, I can feel the power hitting the ground quicker and harder. My biggest problem now is keeping the car from overpowering the tires at the slightest stab of the throttle .

Tom