If you're looking for a straight line tire for just going in a straight line, the PSS is NOT the tire for you. The PSC1 and PSC2 are much better choices. They are softer and a better choice for going fast in either a straight line or in the corners, but since you want straight line only, the Nitto NT555 is the tire of choice but I am not familiar how good they would be under the weight of the C63, or wet weather traction, but you have to figure it's one or the other. You get better wet traction with a PSS or better dry launches with a softer tire like a Nitto or PSC. It is a trade off. You also have to find out how some of these tires will fare under a heavy performance car like the C63. It is a heavy car with a ton of torque, so you will be blowing off tires pretty quickly.
The PSS tires start at 300TW (Treadwear) and go up from there. That is not what you want in either a high performance tire or a street/strip tire. The PSC tires start at 280TW and go down from there and by going down, means a softer tire. The lower the number, the softer the tire. The PSC (Sport Cup) tires are in a higher league performance wise than a PSS and are a great road tire, but to each tire is a trade off. You just have to find out what you can and can live without.

The 285 NT555 fit fine on my car without rubbing on the OE 18" 5-spokes. Lots of people here have run them. Not great fun in the wet though. To be honest, my 60' times were exactly the same on PSS.

That's interesting. 285's fit? That's a big tire. I am wondering then if the Nitto is hurt by the weight of the car. Some tires like the Toyo R888 are a good track tire for lighter cars under 3500lbs, but above that it really has issues. I am curious if the Nitto has the same issue.

The 285/35-18 has a 97 load index which is good for 1600lbs per tire, which is enough even for our pigs.

No - I have never run them. I know a couple of guys that run 19s on their 991 Carrrera Ss for both street and DE use and someone else that does a fair bit of auto-x in a turbo Miata and all three swear by them, but I've never run them myself.

The RE-71Rs do come in the OEM 18" and 19" C63 sizes and have a sufficient load rating for the car (95 F & 94 R), so it would be interesting to find out how they fare. I think they are the only tires with a relatively low treadwear rating (everything else is in the PSS category) that are not R-comps and will fit and support our cars. Would be interesting to try them on.

Have you considered r888's?

I've had many sets of re11's. Love them, but they have like a 200 wear rating. I get 5k miles out of the rears.

They are loud, pricy for what they are and not good for heavier cars.

From what I remember they don't have any (265+) rear 19" sizes. All the diameters are too large.

Correct - but they do come in the 255s though, both in the 18" and 19" sizes which are likely going to hold up better than 265s on the same (narrow) OEM rims. The extra 10 mm of contact patch width is not going to do anything on a track if the tire is too wide for the rim and will squirm, shift and roll under under high lateral loads. A slighly narrower tire but properly suppored by the correct rim width will produce better lap times and last 10x as long as you'll likely destroy the wide tire sidewalls in the first ten laps and overheat (if not blow) the tire from the excessive sidewall flexing.

I've been toying with the idea of getting another set of custom forged rims and gettng 245F & 265R Pirelli Trofeo Rs for my existing 8.5" & 9.5" DPEs. I destroyed a set of Trofeo R fronts in no time, but that was with them mounted on the (narrow) OEM 18s... they did seem sticky enough though, and I'd love to try another set on a proper set of rims.

Good points Diabolis, thanks. I was going to try and fit 285/35-19 back there this year (with a little fender massaging), but my rim width is only 10" - borderline - so now you have me rethinking things.

Loved the R888's on my 996TT, but I've heard that they don't hold up well to the weight of our pigs.

Decisions decisions...

Sure they're loud, but are actually a very good value when it comes to R-comps. And, just try getting Hoosiers, BFGs, Victoracers, PSCs (actually - try finding any of them in a size and load rating that will hold up our C63s) or Trofeo Rs and see how much those will set you back. As for the car's weight, no tires are good for heavier cars. Actually, no *anything* is good for heavier cars except massive brake rotors to stop all that mass.

I like the R888s better than the old RA1s. They have more initial grip than the RA1s, a stiffer sidewall, require less camber, don't squirm *nearly* as much when new (unshaved) and are not outright scary on the drive to & from the track. The only downside of the R888s that I can think of is that the RA1s would hold up until they were corded (essentially becoming slicks at 2/32s) whereas the R888s drop off once they get down to the wear bars. At least those were my impressions.

I've had one track day on the RE-71R's and I liked them much better than the PSS's. They had sharper turn in, better grip for exiting under power, and never got greasy. Next Friday I start a 3 day track event and I have a brand new set of RE-71R's installed just for this. If I get valid data from my track app (Harry's Lap Timer) I'll post any delta's and thoughts or impressions.

That's great to hear (the PSS is not really a good track tire) - and do let us know how they fare after three days of track (ab)use. The RE-71Rs just might be a winner for non-R-comp tires for our C63s that have a high enough load rating, fit our OEM rims and decent for "weekend warrior" track duty.

Clark Kent, how did you like those new RE-71R's on track? I'm actually leaning towards the PSC2's now but interested to hear how you got on.

i guess it depends on what u use the car for, personally, once i changed from the oem contis to pss, i couldnt be happier. for a daily driven car, it makes me feel safer in all weather conditions.
however, great advice was given by a forum member here previously, that was an actual tyre retailer, he said screw all the brand names and just buy a cheap crappy brand, i cant even remember what it was, but he raved about how great it was and how u can save so much money as it had similar performance for much less. i was sold