Quote:
Originally Posted by TrackClub
Seems both the stockers and RE71R will last about 10 days plus some dd driving which is superb in my book.
Regarding Cup2s, i know 2 folks that run them on their GT350Rs (instructor group). They have no issues with them on a like heavy car. I've driven in one of the cars and handled very well and predictably. No TPMS issues either - which IMO have nothing to do with the tires to start with.
But, those tires last about 4 days and cost quite a bit. BTW no idea how a NOVICE could use up a set of brand new Cup2s in a single day. Except that Ford engineers have publicly warned folks to stick to PSS on GT350 (sans the R) as the suspension is set up very differently. So maybe that played a part as that's not what happens on GT350R for absolutely certain.
Edit: on a GT3 Cup2s last 8-10 days (instructor level) with cold psi 26/29 F/R with hot up to 34/39 F/R. So I'd imagine running them at 36/37 hot and getting 4 days on a heavy car is about right in comparison.
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RE71Rs heat cycle out before the tread is gone so visually they might look like fine but the grip is not there (as opposed to other street tires). This is from my personal experience and many others had similar experience, I am surprised they didn't notice the degradation after 4-5 events
maybe it's because the session format or the climate was a factor, not sure.
Speaking of Cup2s, he was not novice, he's a club member and been there many times. The reason Ford engineers warned the users is most likely because the MRC calibration on the GT350 is specific to PSS so there should be no performance benefit also with a softer calibration (and possibly with softer springs) body roll and rubbing might be an issue. GT350 owner that I know said he didn't notice any issues except the treadlife.
Also, they're not that expensive unless you're looking at the Porsche specific compound (305/30/19s are about $360 and 315/30/19s are $420). They also weigh a whopping 5 lbs less than the comparable size tires (305s weigh 26lbs and 315s are only 28lbs vs 31-32lbs) just like the R7s. If they last 4 events that still a great value which wasn't the case on two cars here