I just got back from the track and I had an eventful day. First and most importantly, the brakes performed well. I can’t say they stop any better but I suffered no fade or problems with the fluid boiling. I decided beforehand to do lots of experimenting to see if I could find a faster way around the track. Short answer is I couldn’t. But I learned a lot of what doesn’t work. I tried braking early, braking late, taking the shortest line through the corners, big sweeping curves, etc. Riding up the berm, staying off the berm. Total failure. The tires seemed to be rolling over and I can see the wear too. So I started playing with air pressures. I had started the day with 35lbs in the rear tires and 45lbs in the front. I started going up in pressure and my fastest time of the day was with 55lbs in the front tires and 45 in the back. With the higher pressures I was faster through the corners but had trouble getting the power down. The first run with the high pressures I came off the dogleg and floored it like I always do and lost the rear end. I played with the gas to keep in control and then it snapped back hard the other way. I never lost complete control but the chase took me through the grass in the infield. Bummer. I data logged 3 of the runs. The car gets rather hot. I saw 215º coolant temperature every single time. It does cool down to 200 fast however. I saw a maximum boost of 17.8 lbs. The slowest corner was 25 mph and the fastest straight I reached 75 mph. At full throttle I never saw more spark advance than 15º BTDC. I only saw 100% throttle for very short bursts. (go cart track, all turns) The car shifts early from first to second under full throttle. Luckily the track is all in second gear except for a moment in third at the end of the longest straight. The car shifted early (5800 rpm) to third every time but once, when it shifted at 6345. 6345? I don’t know what happened. Computer hiccup? I’m thinking the next step for me is flipping the tires on the rims since they’ve worn so much on the outside and having the car aligned for the track. Half of my driving on the street is heading to the track anyway. Naturally, I want that big brake kit, suspension, racing tires etc. But I’m going to learn to drive better before I open the wallet. Its the best thing to do. All in all I learned what won’t make me faster today. I learned to find a place to stow the grill and water bottle. (they got loose and were flying around inside the car) I learned the front tires do best between 50 and 55 psi. That 45 psi is too much in the rear tires. That braking early is slow. Braking late is better than early, braking just at the right time is best. I learned the track won’t pay for landscaping service. I think it was a good day for learning.

Les

 

Les: What kind of tires are you using. Your pressures seem too high. I let the air out of my tires to get them to stick so I stay on track. Remember how I talked about the spin I had because I had too much air in my tires. When in doubt, let the air out.
For the sport cups, I'll start out at 25 PSI and come off the track right at 32 PSI, which is good and sticky.
The sport of racing really evolves around the trial and error of trying new things and seeing what works.
glad you had a good day at the track.

I just drove in a Rally and we won. We were 56 seconds from being perfect. Yee Haa.

Jane

 

I'm still on the stock Michelin PS'2's. I'm convinced the spin was from too much air in the rear tires. But the fronts stuck much better with 55 psi. Next time I'm planning to start the day at 40 in the rear tires and 50 in the front.

Les