[s-cars] future of awd and TT handling

[QSHIPQ at aol.com]

Colin
Thanks for coming back to this with some data, very interesting.  I'd  be 
really tempted to lower the backs again some more, or dial the camber  positive 
to get more even temps across the back.   Right now, you are  either too neg 
camber rear or too high pressure rear.  Assuming hoosiers in  the rear, I 
usually start with 2-3 psi difference F/R and go pressure first then  camber.  What 
are your camber settings now?
 
I would now fully concentrate at the back of the car, it looks like  you have 
the front dialed in pretty nicely, hot pressure of 42 on the front is  really 
good with those tire temps.  
 
My .02
 
Scott J
 
 
 
 
In a message dated 5/17/2007 11:24:34 A.M. Central Standard Time,  
ccohen5 at compuserve.com writes:

So we  tried a number of different tire pressure combinations on the TT while 
 
racing it in the SCCA T3 National event two weeks ago.  I got stymied  on 
qualification and in one of the races by failure of first one and then  
another of the spark plug power packs but here is what we did  learn.

Softening the front shocks (rebound and compression) helped  front end grip 
measurably as did higher rear tire pressures.  On one  session I measured a 
hot pressure of 42 having started at 38 and a fairly  even cross tire temp 
starting at 150 on the inside and declining to 135 on  the outside.  This is 
consitant with the rear camber and a lot higher  ( ambient was 75) then I 
have seen in recent events indicating that I am  sliding the rear a little. 
The fronts were also mid 40s although we  started cold at 33, with temps at 
170 plus - very much in the zone for  Hoosiers.

Note I am running an asymmetrical wheel tire combo too with  17" 235s on the 
rear and 16" 240s up front.  My times were 2 or 3  seconds better than my 
last run but Don Istook was able to effect the same  improvement with just 
the softer shocks.  The only corner that upset  the ECU (limp mode until the 
wheel was straight and I got off the gas) was  a slow 300 degree hairpin. 
Fortunately the track out exit is so wide that  I was able to adapt my 
technique to take the corner in 2 phases, getting  on the gas only in the 
second phase where the steering wheel had very  little turn.  But it was the 
long way around and this offset the  torque advantage I would have otherwise 
enjoyed over the Honda S2000 and  RX8s in the class.

So thanks for the help  everybody.

Colin







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