TRAKCAR

Both the MPSC2 N2 and Dunlop Sport Maxx 2 are game changers.
Really hope that I can make either last 4 track days at Sebring, so I don’t have to screw around with another set of 19” wheels and take off slicks that also only last 2 days.

I did 4 days at the Ring on Dunlops. Although faster and pretty good in the rain (Drove on the same 4 day old tires in heavy, heavy rain today from the Ring to Manchester UK today, up to 70MPH OK in deeper water and without the risk of aquaplaning they were fine to 100MPH) I do like the feel of the Michelin’s better. The Dunlops feel like they are graining, make a bit of rumbling noise and give early warnings but they hang on better = faster.

But the Michelin’s feel more precise but give less warning when they let go..

Im happy with whatever lasts longest.
Both can be run a little higher PSI hot. Say 30-32F en 32-34R

Dougr743

I think you could build a quick jack system on the floor of a trailer, or just pull them off the trailer, set them up in a few minutes. hook up the hydraulic ram quick connects and boom, you have a drive over, quick jack, and tires off the ground, Quick jack can run off a battery or generator I believe.

kblask

Do you have any guidelines for rough hot temps to be aiming for? I'll likely bring an IR thermometer and try managing my tires with this strategy at my next track day!

Dougr743

Most warmers will only go to 200, 175 would be a great place to start, somewhere in that 200 of less range.

erliuic

Most advice I've read has been to avoid IR thermometers and use a tire pyrometer with a probe. IR thermometers can be inaccurate for this application.

kblask

Good point, I guess a probe is the way to go to get a carcass reading rather than surface. In theory, shouldn't IR be able to penetrate a few mm into the tread to get an internal reading? I guess the thermometer would have to be properly calibrated, to do so.

Dougr743

I have never used any of them. Just tire warmers, so have no idea what will give you a real solid reading.

M3the01

A lot of good info here. On the gt2rs, start at 26psi on all four? Question I have is at temp, 2-3 laps in, should we try and achieve equal psi front to back? What is ideal psi, at temp, stock gt2rs for front and back?

Also, when to get worried on the track? McLaren is very sensitive to differences between tires but a psi or so should be fine, no?

Ty for the advice

1q2w3e4r

I think that's too low to run on a Cup 2 cold. It's not really a dedicated R spec and I'd worry about the side wall of the tyre at low pressures before the car got heat in them, I'd start at 28-29 and bleed down after the first session, but that's just me.

iphilips

I've run 26 cold on SP2s in my GT3 in the first session of the day (70-80F). It's just a bit too low, takes most of the first 25min session to get them up to spec.

I too would suggest 28ish on the first session then drop some on the first break. I aim to run 33/35 hot.

Also have side muffler delete for context.

Dougr743

Colder starting pressure gets hotter sooner. So if you are too low to start and too low when getting off the track you not getting up to speed to get the tire to perform properly. Its not the pressure at that point, its the speed you are traveling. this is kinda the never ending thread of understanding. extreme low pressure will bake the tire, it will become greasy and stop shedding. I would try your street pressure and see how little they rise, then you may be able to understand the change in pressure is related to heat. In this circumstance, the tire would barely raise.

200+

.1 GT3RS with “R” or “N2” spec tires. 29ft/31rear HOT on a slower speed track. 30-31ft/32-33 rear HOT on a higher speed track like Road America.

carrering

So I think I had this at Thunderhill on This past Saturday. I noticed I had a band of rubber about 2/3 towards the outer edges of the rear tires. Is that a cold tear? I started in the 26/28psi cold and bled them down each time coming off track but each session they got greasy earlier and earlier. by session 4 and 5 the tires were just sliding after half a hot lap. That was their 5th track day. Temp was in mid to high 80’s. So I guess I’m buying new set. Expensive lesson to learn.

I’ll just lower to 30-32 cold and adjust after 4 laps of warm up but sounds like I shouldn’t mess with them after that.

should I get the mpsc2’s with the built in temp sensors? Anyone have some luck with those.

im headed to Laguna Seca in June. Appreciate advice on the track and tire temps. Will be my 4th time there.

hell I might just run my PS4S tires instead

Dougr743

If you continue to lower the tire pressure, your tire will overheat, the temp keeps getting higher and higher. you are baking the tire. So you need to add air, yes add air pressure. More pressure will control overheating, tearing is cold related, the tire is cold, and you push it, it cant shed so it tears, overly low pressure casues overheating, gets too hot, stops sheding rubber and becomes greasy. You want the tire create ***** of rubber, or "the worms" you see on edge of the track. The tire is shedding and allowing the tire to grip while holding opperating temps. Once it overheats, it stops shedding, and gets greasy. you will see the tire become shiny and smooth. Most people overheat their tires, and keep dropiing pressure. So if you go out at 30 psi and come in a 50 psi, your too low at start, if you start at 30 and come in a 30 your too high at start. Then to add insult to injury, you pick up speed as the day go's on and you keep lowering prssure, that increases temp.lol

so lets play a game, if you go faster during the day, you add pressure or remove pressure? This is what tire warmers are for. you heat them up, set pressure. The temp is to the optimal tire temp, or opperating temp. not too hot, not too cold. If you came off the track, and the tire is way higher than the warms, you need to aid pressure to regulate temp, if you are lower than the warms, you would remove pressure. So its simple to start at base temp.

No warmers, set to ambient temp recomended for tire, cup2 has a recomended track setting, then check the pressure and tire temp as soon as you get off the track, if you temp is higher than recomendation, add pressure, if lower, lower pressure, if perfect, dont touch it. As you get faster, you add pressure.

TRAKCAR

^^^ This varies widely and makes the Dunlops so different from Michelin’s with the current versions.
Never mind Hoosier R7, the worst.