I ran the car at MSR Houston last Saturday and Sunday. The open track group was Chin Motorsports and all I can say about that is a VERY BIG THANK YOU!!!!! They went out of their way to find a way to run me and my car given that they mostly have road going high performance street sport car owners as customers. Lots of very high end Porsches, Corvettes, Mustangs, BMW's etc.
Their policy is to have first time customers start out with a instructor ride along. But all of their instructors were rather tall and were unable to fit in the car with a helmet on. So in the end we did a lead follow arrangement that helped me with learning a track that I had never been on and at the same time fulfill their obligation to their policy. Very cool, and again thank you.
MSR Houston is a fun, well maintained, and safe track with lots of run off. It is about 2.4 miles long and has a combination of slow speed corners linked together and longer straights with faster sweepers at either end of them. Great for test and tuning. The track is plenty smooth enough for my SLC and generally a lot of fun.
It was cold. In the mid 30s overnight and in the 50s until 11am or so with afternoon air temps up to low 60s. Track temps were very cold to low warm. Little wind but sunny. Pretty nice days really.
Saturday morning was mostly taken up with Chins beginner system but once we had that sorted out and I was turned loose I began to pick up the pace and by the afternoon I think I was running fast enough to collect good data.
Cooling system: From what I can tell it works perfect now. The Davies Craig controller runs slow until the system begins to warm up and then holds the target temp SOLID. My temp setting was 191F and I never saw the water temp above that.....not once all weekend. I think mostly that was the new radiator but also the final layout of the system is now correct from a engineering perspective. Everything is in the right place now and works as it should. The only thing to do now is run the car on a high 90F day and confirm these results. But I think its good now.
Tire pressures: I tried to run the car on Saturday morning at 30psi all because it was so cold and I didn't believe that the tires would pump up given the slow speeds we were doing with the lead follow deal. 30psi is still too high. In the afternoon on Sat. I went down to 28psi all and was able to pump up to 30. Still too high. Sunday morning I went back to 26F 27R and ran harder to finish session #1 at 28F 29R. Remember it was still cold with air temps at low 40s @ 8am. By the second session, 10:30am, it warmed up to low 60s, I reset warm tires to 26F 27R and they came up to 28 all and felt pretty good.
Brakes: Played with bias every session. Added to front with 1 or 2 turns each session from centered. As I added front bias the car began to allow more trailing braking and generally felt better each time. Stops good, would stop tires if pushed on hard, and stopped straight every time. I think the brake components are close enough for now with maybe just a higher coefficient of friction pad. The pads on the car now are about .45 and I could see trying something above .6. This will require some thinking before the next outing.
Setup: Started with 0 angle of attract on rear wing, shocks setting unchanged from last time out, about center of range both compression and rebound, springs 750F 850R, antiroll bars, rear 3 of 6 holes from min rate. Camber -1.5F -1.0R.
I did add +4 degrees to rear wing. That was felt above about 85mph in high speed sweepers. Everything else I didn't change much. Next time I would like to stiffen up shocks about 2 clicks both R&C and loose up rear antiroll bar a hole or so. I also think the car would like more camber. At least another -.5 all.
I began to feel some over steer in one of the 4th gear sweepers at constant power. Some of this was helped with more rear wing but the wing effect goes away below about 70ish and the over steer comes back with adding power. Car will power over steer at 50mph if a lot of power is added in 3 gear. I did loop the car at about 45MPH by putting too much power on early out of a slow corner. 2nd gear is all wheel spin........useless really. I think that I would use 3rd in any corner under 60 down to about 20mph. Plenty of power.
The last session I tried to add revs to the back straight. I held the motor to between 5500-5700 until then. Let it go to just short of 7K. Lots more power up there.
Fuel: car used 5 gals ever 30 mins.
Temps: water 190-191f all the time. Oil 210F solid, gearbox ran as high as 210-220F. What do you guys think about gearbox temps. 220F too high? This car has no gearbox cooling.
Well that's it! next stop maybe COTA in January.
