mooty

i agree with ronCT.
in order of pref (in terms of grip, and only talking about the michelin brand at the moment): real mpsc, oem n rated mpsc, ps2.

on track, sure i prefer real mpsc, but on american streets, especially metropolictan usa, like chicago, nyc, sf, la... any sort of mpsc is somewhat wasted. i mean how fast do you imagine exiting the offramp at wilshire blvd or civic center? 50mph doesn't need mpsc and you wont get enough heat in them to matter anyways. now if you are in EU or montana, then it's a different story.

what i am saying is that yes, mpsc is better, grip is there, but you wont use it.

frayed

I'm with Mooty.

PS2s (or their equivalent from a competing vendor) for the street. I like their steering feel, wet traction, quietness, and more consistent grip over a wider range of temps. Street tires tend not to kick up stones like R comps as well. I haven't tried Robin's Contis, and I've had mixed luck with contis in the past (except for on my mountain and road bikes).

RA1s on track (if you drive to the track) or Hoosiers (if you trailer). To me, the MPSCs don't have the forgiveness of the RA1s as the RA1s let you get away with bigger slip angles. They also don't get as greasy as the MPSCs toward the end of run sessions, and are easier to get up to temp. Shaved RA1s rock. I think the RA1s successor is out now in appropriate sizes, the R888. Haven't tried them but reports from the bmw camp are pretty positive.

mitch236

Another concept about using real MPSC's for the street is most drivers won't be able to get the tires up to proper temperature or pressure on the street.

Nordschleife

Well, in Europe, the general rule is to use 3 tyres per year if running MPSC on the street. MPSC are not good at the shoulder seasons, so many people will run something like -

Winter - Dunlop or Yokohama Winter AVS Sport
Spring - Continental Sport Contact3
Summer - Michelin Pilot Sport Cup (the real thing)
Autumn (Fall) - Continental Sport Contact3

Try the Contis (but made in Germany), you will be surprised.

R+C

RonCT

All excellent points and the biggest might be "when could you possibly use PSCs to their potential on the street?" I find that they need 2 full laps to get any heat in them and no amount of street driving is going to get them to where they want to be. And what's the point? Where could you possibly experience 1.5+ G cornering and 1.4+ G braking forces on the street (I use "+" because I got those readings on PS2s at Watkins Glen)? And if you did try to attempt that, you'd be breaking all sorts of laws because you'd be unsafe (lack of up-road information, no corner workers, etc.). Then again, maybe in Europe there's a case to be made for PSCs or RA1s on the street due to the highway system, but even there, I question whether there'd be any real world improvement over PS2s or Contis...

P.S. I was using the RA1s on the street to break them in and wear them down a little (didn't get shaved - figured I'd do it myself with some street miles and have tread for wet track conditions) and boy, did they get noisy, especially after 2 days at The Glen. On the way home they were screaming, especially right at 63 MPH.

Holger B

PS2's are an excellent street tire, but in my experience they're only good for a few laps at the track before they get greasy and performance drops way off.

Not a big fan of Conti's (and my parents met while working there), but haven't had a set in years.

mooty

amen, someone heard me.

RonCT

Holger, what pressures you running because I've never experienced what you describe. 1:03s at Lime Rock and 2:17s at Watkins Glen bone stock on PS2s with me just learning how to drive a rear-engined car. And the G-forces recorded by TraqMate are really impressive for the PS2s. Hmm, I just took a look back at some TM sessions with my old M3 on 18" PSCs as well as a friend's 996 GT3 on PSCs and the cornering and braking forces from my oem PS2s far exceeded those of the 18" PSCs.

Holger B

Low to mid 30's hot for PS2's. Much quicker lap times on MPSC's at tracks out here.

Porsche Rebel

+ 1. No problems here. Love my Pirellis.

RonCT

Ahh, I think that's your problem with the PS2s... I'd have to go back and check my notes but optimal performance for PS2s is in the low to mid 40s. I think I ran 41 front and 43 rear hot maybe...

Holger B

When the pressures were that high, the car slid around too much. Could be the way my car is set up, 18's vs 19's, track temp, etc.


Go Huskies!

KINGSRULE

I'm not sure the Continentals come in the correct size for 7 GT3.

Nordschleife

Here are some Conti options from their Sport Contact3 and HiSpeed (360 kph) ranges

................Porsche.......Rolling Radius............Conti...........Rolling Radius
Front___235/35 ZR19_____12.74 ________235/35 ZR19______12.74
___________________________________ 245/35 ZR19_____ 12.88

Rear___305/30 ZR19_____13.10________ 325/30 ZR19______13.34
___________________________________ 325/25 ZR20_____ 12.70
___________________________________ 315/25 ZR19_____ 12.60

You may need to do a little fender rolling or spacers to ensure sufficient clearance. There is also the opportunity to slightly change the overall gearing of the car and theoretically improve acceleration.

If you check the reports of the last Tuners Grand Prix in Sport Auto, you will see that many tuners used Conti Tyres to achieve optimal performance.

340Elise

Can anyone chime in on how similar the Cup tires are to my A048's on my Exige S? Just curious is they would have similar characteristics in terms of heat cycling, getting them up to temp and such. I know the wear rating is about the same, and the mileage between the two tires is about the same.

Just curious of what to expect when I go from my Exige S to the 997 GT3.