PierreTT

Folks,

Too many treads, too much information, cant find tha concensus on the best target HOT pressure for the track...

Tomorrow will be my first DE with RE71-R. Always ran on Michelins... I used to prefer 31-32 Hot on MPSC2...

What are the numbers for RE71?

Thanks in advance and sorry if this has been discussed to death already...

Pierre

orthojoe

I like 33-34 hot for Re71r

PierreTT

Quick on the track, quick to respond on technical/track oriented tread!!

Thanks Joe, much appreciated

orthojoe

LOL! You know those are the threads that catch my eye!

johnsopa

I like 32 psi hot. Typically start with 25-26 cold. If you're new to the tires I would start at 28 then bleed off at the end of the first session.

DC640

I ran 32/33 hot. The temp drops off fast onnthese tires in my experience

Starting believe 26 triggers tpms even on circuit mode. It is annoying. I guess I have to learn to just ignore it. I know those aren't that accurate and I know my pressure before starting the session. Just take it easy to get back heat in the tires before pushing it.

PierreTT

Thanks Folks!

Drjimh

Ditto!!!

johnsopa

One more thing... Assuming you're running a normal clockwise circuit, when you come off track and measure/bleed pressures, start with the left rear, then right rear, then fronts. The rears tend to heat soak relatively quickly due to the engine heat in the back. And do the measure/bleed in one go. If you come back a few mins later, the pressures in the back will go back up a bit due to the heat soak. I don't bother measuring again until after the second session.

Hope this makes sense.

MarcD147

question about this heatsoak.....

I typically bleed the rears twice...
during my first session of the day I typically come in half way to bleed down to 31 (I knew they will go up more) when I am done checking my rears will have gone up to 32-3 again and I bleed them again before getting back on track.

is this bad?

johnsopa

Hey Marc!

I don't think this is "bad," just unnecessary. That 1 psi change over the span of a min or so is exactly the heat soak I'm talking about. Some is from the engine but also remember that the tire surfaces are still hot, but the car's not moving, so some of the heat transfers "inside" to increase the PSI. Once you roll a bit they'll cool down a bit unless you go back to 10/10ths driving.

I'd just do it once then go back out.

Even if you get to 35 - 38 or so out on the track, it's not going to really hurt anything, IMHO.

MarcD147

I actually think this kills the tire; running half a session over 36 (so 37 and up) glazes the tire and will cost you speed and tirewear going forward)

i am very diligent and if I hit 36 I hotpit to bleed
at 34-35 I abort a lap that I made a minor mistake on and use the remainder of the lap to cool the tire down.(7/10 instead of 9/10)

typically after the 1st/2nd session I got the tires perfect in range and my hot sessions will be steady 32/33

electron mike

I like 30.5 psi hot personally after experimenting with many sets of tires.

PierreTT

Ran 31-32 psi and it felt great, easy and predictable.

Maybe it is the car too... It was my first time on my local track with a Cayman. GT4 is easier and less intimidating than my previous GT3s. Needs more hp though... chassis can take it!
Great car

Chris Hebert

I got my PB lap time @Summit Point pulling into the paddock @31 psi on RE71R's.