Larry Herman

147 - Not Bad! I had my car there a few weeks earlier and on the MPS2 tires (OEM) was up to 151 before the braking area. I was running the Pagid RS-19 pads and they provided much more stopping power than the tires could handle (hence the constant presence of ABS). I had to brake gently enough to stay off of the ABS, and that netted me my shortest stopping distances. Stickier tires would help alleviate that problem, as the increase grip would allow for better use of these powerful brakes.

4 Kurves

John - I've been struggling trying to find the right pressure set up on my MSPC's as well. Yesterday I was out at Streets of Willow (very tight track that really isn't ideal for testing setups on a GT-3) and it was very hot. I kept dropping the pressure to (eventually) 34/38'ish and I still felt very loose. The high amibient temp didn't really help (about 105 degrees) but still I couldn't seem to get a handle on it. The Cups have about 10 heat cycles on them so I assume they still have grip (I certainly hope so).

Couple of questions:
1. Were can I get a good pyrometer on line?
2. How do you know what the correct temp is?
3. Should the temp be the same across the tire (inside, outside and middle). What does it tell you if it isn't?

Thanks,
Kevin

Johninrsf

4 Kurves,
Dave Turner Motorsports on Magnatron in San Diego carries many different types of pyrometers. Call him and ask him for a simple probe type and he will send it to you. His WEB site is www.Daveturner.com.
For getting the right tire pressure, you need to (1) get the tires hot by running around the track several times at speed, (2) go to the closest safe place where you can stop the car --do not take a cool down lap, (3) have someone waiting there with a pad of paper, pen and pyrometer (actually two people is better, one to read the pyrometer and the other to write the numbers down--turn your front wheels to the stops in one direction or the other to make access easier, (4) check each tires' temps in 3 places: the outside edge of the tread you would expect to contact the track (in other words, NOT the sidewall), check the middle of the tread and the inside edge, (4) add the numbers for the inside and outside edges and divide by 2; you want the average of the inside and outside temps to equal the middle temp. If the middle is higher than the average of the inside/outside, you are overinflated. If the average of the inside/outside is higher than the middle, you are underinflated. Adjust pressure by a lb. or so and try again. If you start at 34/32, you will be close with the MPSCs and adjustments will be small.
Don't worry, for now, about actual temps. They will range from the 160s to 200 and that's OK. And the difference in temps between inside and outside edges is a function of how hard you are driving, the negative camber and the type/direction of turns. Textbooks on setup say that optimum grip comes when the temps for the outside and inside edges are equal, but in actual practice, most cars are not setup this way. How much camber are you running?

4 Kurves

I'm running -1.7 and -2.4 - about the max my guy could get on the alignment.

Thanks for the advice - I'm going to give this a try.

-Kevin