[JimMueller]

I took my daily driver to a little road race practice course today. Each lap was only a minute and I'd stay out there for only 5-10 minutes. The first session I just wanted to work on tire temps, then I let it cool down. I actually logged the second session and have some questions.

Water temp: I live in Florida, so I run 100% distilled water with maybe 1-2 bottles of water wetter. After 7 laps, I noticed the coolant temp was at the 3/4 mark so I brought the car in. The scan tool later revealed the temp had peaked at 244*. Isn't that a bit warm? Solutions?

Brakes: In the front I have standard C6 calipers, Trackbrackets, DTC-30 pads, new standard C6 rotors. In the rear I have Powerslot rotors and HPS pads. All stainless lines and using SRF fluid. While it didn't have a problem stopping, the pedal became easier to depress and started grabbing hard closer to the floor. I didn't like the feel of this, how do I remedy it?

The log also shows it was pulling 4* of timing on all WOT sections. I bet I have a knock sensor code (IMG:http://www.frrax.com/rrforum/style_emoticons/default/mad.gif)

[JimMueller]

Here's some tire data if someone can confirm my thoughts. 315/35/17 A6's on 17x11 wheels. Link to the track diagram is here. All the outside corners are off-camber.

Corner Out/Ctr/In/Pressure
LF 167/161/161/42.5*
LR 136/145/141/37.5*

Corner In/Ctr/Out/Pressure
RF 156/143/140/42.5*
RR 140/145/133/38.5

Do any of those numbers indicate I should tweak my camber or caster? Because I didn't have a compressor, I started the first session with 35* in all four tires which I assumed would be too high and I could just bleed it off. It seems like dropping 1psi drops the center temp about 3*, so I planned to use these pressures on the third session (which I didn't run because of the water temp concerns):

LF 43.5
LR 35.5
RF 44.5
RR 35.5

The handling was decent for the most part. I used 3rd gear in the increasing radius sweeper and the rear end wanted to slowly slide out on me. After the sweeper it straightens out for before a ~60* right hand turn going into a S-curve. I tried braking late every time for that hard turn and never engaged the ABS, but the soft pedal (which returned to normal on the way home) gave me concern. The pavement in the middle of the S-curve gave me traction problems because it is rough.

I've been there a number of times in the past (when I had a built LS1 instead of a built LS3), and I think I usually used 2nd gear in that increasing radius sweeper because I remember having to shift. I'm not sure what's quicker to the 60* turn...leaving it in 3rd all the way, or using 2nd (which will cause more traction problems and less speed in the sweeper) and then shift as necessary.

Front suspension is Koni DA's with 650# springs and 35mm solid bar. Rear suspension is Koni DA's with 300# springs,UE lowered PHB, 24mm solid bar, UETA, UE LCA's. I finally got around to adding the 1/2 turn of preload Sean suggested last September. I'll check the zip ties today when I put the street tires back on.