[Sp00ner]

Morning folks!

Getting ready to replace the corded stock run-flats on my SS, and looking for some opinions.

Our race format is essentially 10 min HPDE practice runs for the first 1/2 of the day. These are, of course, not timed. Our timed runs are standing start 1 lap 'hero laps'. This year we're only having 4-5 competition days but an additional 2-3 full HPDE days. (Plus I might go outside the club for some random track days) Probably looking at 10-12 events total for the season.

So I need a tire that isn't going to go greasy in 5-10 laps as well as one that grips really well from near ambient temps.

Given the daily driver requirement, I feel like the only real option I'm looking at here are the good 'ol MPS4s. I've looked at the RE71R, and it sure seems like they aren't going to last the whole season given the daily driver requirement. The fact that they grip like hell in the rain is also a big plus, since we run rain or shine for competition days.

Thoughts/comments?

[Lafourche1]

I am running the MPS4s. I will not get any track time with them until 3/24-3/25. That being stated, I would be hesitant about running a hard lap on any cold tire. You risk tread separation or an off-track excursion due to lack of traction.

If you do go with MPS4s, monitor your tire pressure during your sessions. There are some credible reports of tread separation due to over inflation caused by heat expansion during track sessions.

Just my .02.

[Sp00ner]

I'd certainly rather have a warm-up lap, but that's not my call. Fortunately, the turn around from run to run is usually only about 30 mins, so the tires are exactly 'cold', but certainly not warmed up either.

[mbar]

My RE71R did a good job as a dayly driver rain or shine if you can handle the noise. On a 1:30 track they improved my lap time by 3-4 seconds. They still need a warmup lap...I find it dangerous getting on the track without warmup.
So far they are at about half-life with 5 days at the track and 5000 Road miles...but this is very personal.

[Norm Peterson]

Originally Posted by mbar

My RE71R did a good job as a dayly driver rain or shine if you can handle the noise. On a 1:30 track they improved my lap time by 3-4 seconds. They still need a warmup lap...I find it dangerous getting on the track without warmup.
So far they are at about half-life with 5 days at the track and 5000 Road miles...but this is very personal.

That's something I could easily live with for the track set that only has to see enough street miles to get me to the track and back.

Do they fall off much toward the end of a 20-minute session?


Norm

[mbar]

Originally Posted by Norm Peterson

Do they fall off much toward the end of a 20-minute session?


Norm

You should watch the pressure closely with these tires. 2-3 psi above the recommended hot pressure and they will get greasy. I start with 28 psi, they will function well between 33-36 ( for stock Camaro SS size).

[Norm Peterson]

Good information, thanks.


Norm

[Sp00ner]

Originally Posted by mbar

My RE71R did a good job as a dayly driver rain or shine if you can handle the noise. On a 1:30 track they improved my lap time by 3-4 seconds. They still need a warmup lap...I find it dangerous getting on the track without warmup.
So far they are at about half-life with 5 days at the track and 5000 Road miles...but this is very personal.

I hate the lack of a warm up, particularly since practice is 5-10 laps. The first 2 turns is nothing at all like you've just gotten used to.

If the runs are cycling quickly, the tires stay relatively warm, but not enough.