gator9_911

Sorry if a lot of this has been covered in other posts....but I could not find answers to some of my specific questions. First time MPSC owner and trying to better understand these things.

1) Wear? Can I wear these down to the 2/32" indicator or is there another limiting factor
2) Heat cycles - Should I track these or is it all about the wear indicator (#1)?

3) COLD pressure - in 80-82 degree FL weather...have been starting the tires out @ 25(F) and 26(R) psi. too low?

4) After one session (20min high speed HPDE) tires come into pit hot @ 29.6(F) and 31.2(R). To hot? or hot enough?
Thanks for any advice or experience!

GuyIncognito

FWIW I found they heat cycled out way before they were down to the wear bars. it's been a while but IIRC maybe 15-20 heat cycles and they were toast?

sorry I don't recall the cold or hot pressures. getting old, I guess...

gator9_911

What is the best time period on the track to quantify (1) heat cycle? 24 hours cool down? Typically run (4) 20 min sessions on SAT and the same on SUN. Is that two cycles? or 8?

Thanks again for the help. Rookie Question(s) I know.

FFaust

- 8 sessions = 8 heat cycles
- 40ish heat cycles is a ballpark for them falling off. I do more with mine, but they just take longer and longer to heat up and get sticky
- I normally shoot for approx 35 psi hot on all 4 (~28 - 30 cold)
- These things last forever wear-wise. They will harden at some point and become unpleasant to drive
- They are ok in the damp, but beware of standing water as they like to hydroplane

I love the Cups, they are my go-to tire.

YMMV

996FLT6

1)I wear them down to the cords before changing. Rears wear faster like 2 rear 1 front when time to change them.
2) each session is 1 hc so record how many. Big range on how many hc's dependent on driver could be 12hc could be 40+hc.
3) I usually start at 24/25 cold then it usually goes up 10 psi so I adjust to 31 hot psi all around- that's dependent on driver as well.
4) I do like mpsc's - very predictable tire.
Hope that helps ya. Mike

MJP911

I shot for 32 hot all around. Some go for 34.

AudiOn19s

My set last year was shaved new to 4/32 and the rears were bald but not corded before they were toast gip wise. If you run them from full tread (6/32) they will be out of grip long before you are out of tread.

I got to heat cycle ~34 before I took them off the car but the last 4 heat cycles were not very good at all in terms of grip, they had really fallen off performance wise.

I liked 30-31 hot all around.

Andy

gator9_911

This is a lot of help .Thank you all. Since I have to to drive to the track occasionally (150 miles each way)....would that be considered a "cycle". Cant imagine that the tire gets that hot doing 75 on the interstate.

Also, sounds like a longer session (i.e 30 or 40 versus 20) would almost be better for the number of cycles.

AudiOn19s

Don't know that it equates 1:1 as a heat cycle but feel your rear tires after a highway trip and you'll be suprised with the amount of heat that gets put in them.

Dudley

I saw a fellow with tire warmers on his Cup Car. He said that they did not allow the tire to cool down, eliminating a heat cycle. True?

spare tire

NO, Not true. Eliminating a cooling cycle does not mean the tire is as good as before. Just look at racing. Indy, Nascar, F1. Why would they change tires during the first heat cycle? Because the tires are not as good!!

spare tire

MPSC I use them and shoot for 32-33 front hot and 33-34 hot rear. I usually gain 12 lbs of air pressure so I start at 26 lbs cold and bleed them down after the first session. I cannot drive hard during the first session for this reason. Starting out at 20 pounds is not good for the tire.

Qwickrick

I drove my new to me RS to Lime Rock this past week, and after the first session, the MPSC's were toast. Being the second owner, I have no idea how many HC's these tires had seen previously.

Car had severe understeer, and first I blamed the sway bar settings, but even after bleeding the tires back down to 32 all around, the understeer was still severe.

Is there a good second choice to MPSC's? I want to arrive and drive and don't want to do wheel changes.

Also, what are your sway bar settings with stock GT3 RS suspension?

spare tire

Severe understeer is usually alignment related. Not all former GT3 owners are track rat, rennlist, dial the car in, type of guys.

rodneyr

The other thing for MPSC's is if you drive to/from the track you should be using the normal street pressure 32/38 - I believe. As others have mentioned cold around 25 and hot 35. After the first session I usually need to bleed 2 lbs out, second session about a pound and typically for the 3rd and 4th session the tires are spot on.