rezanourai

Sorry, I know there are a ton of tire threads, but none seem to answer my question as everyone seems to have different intended uses.

My 991 S is mostly used only as a track car. I do track days fairly regularly (shooting for 10 or so this year), and have just started some autocross as well. I have another car for daily driving, but I don't have a trailer so I need to drive the 991 to the track and back.

I'm looking to go full R compound tire, given I don't daily the car. I'm seeing a lot of mixed recommendations, and I'm also really confused by Pirelli's naming of Corsa vs Corsa "System" which seem like 2 different tires.

So, my priorities:
1. best dry traction
2. smooth edge so I can find it and stay there (vs abrupt breaking loosing)
3. don't care about wet as I don't daily the car
4. in distant last place is wear vs price

options I'm looking at, but need some help:
1. Michelin Sport Cup 2 (N0 ones that are OEM on the GT3? or standard?)
2. P-zero Corsa (PZC4)
3. P-zero Corsa System

Also, I'm wanting to step up from 295 to 305mm in the rear, but leave the same 245's in the front to avoid rubbing. Is that a reasonable thing to do? I really like the way 305s look.

All suggestions appreciated! Thanks

rezanourai

Worth mentioning I looked at the Trofeo Rs as well, but they are over 2k for a set, and have a wear rating of 60. Not sure I want to deal with that on a long term basis

arter

Some Basic choices for streetable track tires for the 991 are:

1) Bridgestone 71R's - faster than MSC2's for the first several laps and then they slow a little. Time trialers love them and they are cheaper than the other options. Can only get 295's in 20 currently. 305's in 19's available.

2) Mich MSC2's

3) The new guys Pzero Corsa (PZC4) which took 4 seconds off the ring time for the new GTS ( compared to the std Pzeros). Probably not as fast as the MSC2's but I have not seen a comparison. Wear rating 80 on these so they may be better than I think.

4) Dunlop Maxx Race - seem to have fallen out of favor.

5) Nitto NT-01 - great if you can fit 18's, not sure if 19 sizes will work. Handle heat better than 71R or MSC2's and wear like iron. cheap

StormRune

As arter points out, its my understanding that the RE71-Rs are a great tire for autocross since they perform very well at the more moderate temperatures you'll deal with in autocross. Most of the track tires require more heat to hook up well and in autocross you need a tire that hooks up fairly cool out of the gate. I've been considering getting them for autocross and they are very popular there on a number of different cars. I do wish with they made a 305 in 20" but they don't. My Pilot 4S's performed much better than my original N0 PZeros so I'm not too unhappy at the moment. The N0 PZeros are terrible in autocross but those weren't on your list anyway. I don't intend to track so I have no opinions there.

I guess the bottom line consideration is that if you are doing both autocross and track, it would likely be ideal to have different tires for both and mount them on different wheels. That raises your initial costs, but eventually the tire costs would be the same since each would wear more slowly... not considering the extra wheel costs.

Quadcammer

my experience is fairly limited, but I've been very pleased with NT01s on my boxster.

rezanourai

Thanks guys. I looked up the NT-01s, and the do make 20", but not in the widths that I need.

I do HPDE more than autocross, so I want to optimize for track use more than auto-x. Sounds like dedicated tires for each is probably always going to be better than finding a compromise tire to do both? As long as both can be driven to/from the track, I could swap at home before driving to the event, instead of hauling a set of wheels with me everywhere. I'll look into it.

Okay, so then it looks like for the sizes I want, and track days as the primary use case, it's down to SC2 and PZC4s. What's the difference between the PZC4s and the "Corsa System"? Is the System not as aggressive of a tire? And if I go the route of having dedicated tires for auto-x, RE-71Rs seems like a great choice there, even in 295 width.

arter

You can use the 71R's for HPDE as they are used by many drivers in the groups I run with.

The MSC2's might be your best, first choice for now as they are a known quantity... street/track.

The PZC4's are too new, I would wait until Tirerack or someone elese rates them. The corsa "system" tires are more street tires than track.
The Trefeo R's are track tires. I tried them once, didn't work for me over the other tires , especially given the cost.

mdrums

I wish the B'stone re71r came in 305/30/20....! I wish a Nitto NT01 came in correct sizes for 991... NT01 is awesome....Nitto is missing out with 991S, 991 GT3 and 991RS rear sizes!

rezanourai

Thanks all for the info!

I've decided to try out the SC2s the first time around. I went ahead and selected the option to have Tirerack heat cycle them, was that a good idea or waste of money?

Also, anyone know if I need to add any spacers for the 305s in the rear? I can't find anything conclusive in my search, but doesn't look like it.

StormRune

You don't need spacers for 305s, there is more than enough suspension clearance not to worry.

FifthGear

(I see you've made your choice, this might help others...)

I've run the NT01s on my track car (M3) for years and am very, very happy with them. I've set some great laptimes with them. Compared to slicks, you'll have an easier time with temperature windows and you don't need to worry about heat cycles as they will likely keep most of their grip level almost until they cord.

Although the RS-3 used to be a great street tire for the track (last a long time and doesn't lose chunks of rubber, superseded now by the RS-4) I'm hearing that the RE71R is now the tire of choice in that department.

leanofpeak

Some of you should look into Toyo Proxes R888's.

Around $1500.00 for a set.

About $500.00 cheaper than a equivalent Michelin set.

The Michelins are not $500.00 better.

rezanourai

My buddy runs the R888R tires on his GTO, and he really likes them. However, they don't come in the sizes I need

LexVan

Good tire choice.

Skip the heat cycling. And pocket the $100 charge. This was the advice from the Michelin race engineers for the Porsche team in the Porscheplatz this past weekend at Road America.

drcollie

Agree with LexVan, that's a waste of money (so is shaving the tire) unless you are going racing and want to be a top three finisher. For a HPDE tire, you are going to heat cycle the tire every time you drive on it.

Three reasons to mount the R-Comp's at the track and not drive out on them.

1) The drive to the track is a heat cycle. Every heat cycle reduces the tire's grip. When the tread begins to turn a bluish cast from those heat cycles, they're all done - time for a new set. You will usually run out of heat cycles on a tire before you run out of tread.

2) R-Comps have virtually no puncture resistance. So easy to get a flat on one when you run them on the street. And you never patch an R-Compound - pick up a nail or screw and the tire goes in the trash.

3) They are treacherous to drive in the rain.