Frank 993 C4S

First you need to figure out how long your R7s last without significant degradation based on YOUR driving. On a light SP2 car, they should last quite a bit. Then you also need to keep in mind that for a regular PCA Club Race weekend, there are up to 11 track sessions:

3 Practice Sessions
1 Fun Race
1 - 2 Warm-up Sessions

Maybe 1 Qualifying Session
1 - 3 Sprint Races
1 Enduro Race

Ideally, you want to manage your tires so you have good rubber for Qualifying and the Sprint and Enduro races (if you're interested, particularly for the two points races). For all the other sessions, you can run your scrubs from he previous weekend. This requires two sets of wheels. In reality, a lot of SP2 guys live with 1 set of wheels with Hoosiers and one set of wheels with rain tires.

ProCoach

No, most of the tires I have data for don't offer "tire company machine" heat cycling.

Yes, me too!

kgorman

This thread is gold.

I recently started running DH's... I have raced on R1's, R888's, NT01, RA1, and others. But this is new territory. Awesome territory.

v-tach

Most competitive Sp2 guys have 3 sets -- scrubs, new set and rains

ProCoach

Agreed.

Frank 993 C4S

For the front runners - of course!

jwasilko

I'm happy to be in a Miata where the wheels cost $90 each (cheaper than the tires).

I have at least 5 sets:

• NT01 for playtime
• 2 sets of R7 (old and new)
• 2 sets of H2O (wet, old and new)
• A set of A7

jrgordonsenior

Don't go out in a light drizzle....

mark kibort

personally, i like rain and slicks. see 2010 GMG GTGP race . that was interesting .....half the field on slicks in the rain..........only a few wrecks

ProCoach

I don't particularly care for rain and slicks, although I did win my first race on slicks (real, no tread at all, Hoosier 7/20-13 and 9/22-13 R45's) at Barber about fifteen years ago when the bottom fell out on the way to the grid. Fell off first lap at T5, but got back on and as the track dried, the race came to me. Track never completely dried, but you just be careful.

IF there is no standing water, and it's not raining (can be misting lightly), I go on slicks, thank you very much.

mark kibort

yep.. that was the debate in the paddock... no standing water, lets go out on slicks. ..problem, it deteriated into a good rain race with puddles. funnything was, it was harder driving home in the rain on slicks vs the race, and that was crawling around at 50mph, vs 100mph tops in the race... never qute understood why that was. the turbos were funny in the rain..... they would hit the powerband and spin the tires to redline in nothing flat! very entertaining!

333pg333

Another thing that nobody has mentioned is oil and grip. Way back when my 944t was relatively mildly modified I went from R888's to some Hoosiers and really noticed an increase in grip. The 944 motor is prone to spinning main bearings when under higher G loads, so be careful to keep an eye on oil levels and don't use too light a viscosity. 20w/50 is generally accepted as a good starting point. You might need to set the geometry up differently from your street tyres too. Generally more negative camber. Your starting pressures might be different too.

mark kibort

No one knows this oling issue, than the folks of the 928 community. (half a 944 engine for those interested) ive been fortunate to debunk all the concerns by using 20-50weight amzoil and (on occasion , redline) to fight foaming which i think is the main issue with oil starvation, not g loading. the thought was high g's capable with oversized R compound tires. ive gone as large as 315/335s with toyos, yoks, and then hoosiers R and A's (in that order) and never saw an issue... then , everyone said slicks were going to be the issue.. ran on 3 heat cycle DH pirellis and had no issues but much more grip to. then, the issue was going to Wilow springs (928 killer track.) also saw no issues. a turn is a turn in my book and we have plenty of them here at sears and thurnderhill (duration of 1.5g and time of 5-6 seconds at high RPM)

the other thing i also saw, was mixing and matching was also not an issue. i ran the DH slicks on the front and the hoosier R100s on the rear (also old A6s on the rear) and never had an issue, other than a handling push problem fixed at some pretty handling intensive tracks, such as Sears and Thunderhill.
(i dont recommend this, just saying i did it without any adverse effects)

However, i was very dilliegent about oil level maintenance! i do think with high g loading you are asking for problems with slicks and low oil levels in a stock sump'ed engine.