frayed

It doesn't state "in the same or opposite direction, respectively" so its slightly ambiguous. But I think a plain reading of that statement associates 3 degrees with turning the same direction.

wanna911

Relative to the best performance tires out on other "supercars" yes, they are far below par. But the hierarchy must me maintained. Any better tires and the Turbo S (and probably base Turbo too) are faster than the GT3, making the GT2 less desirable.

Porsche are perfectly ok with the Turbo being a less than desireable circuit car. It can still run 10s 1/4 mile and 2.8 0-60 on those pirelli's. Wow factor for the accomplished.

The good thing is that it's an easy problem to fix. The 991 Turbo S would be a straight monster on MPSC 2. It really would kill the market for the GT2 as Porsche would have a hard time making the GT2 faster. Now they just give you the car, and if you want the tires, you go buy some and take over the track.

sunnyr

Loaded question - considering how potent the Turbo is, what if the next "GT3" has AWD? Is it an acceptable aid in the incessant search for faster lap times or is it a step too far?

wanna911

I think that cannibalizes the Turbo Market and blends the variants too much. Unlikely, unless it's a 918 sort of AWD. Which would match well with the GT3-R Hybrid.

SamFromTX

The good thing is that it's an easy problem to fix. The 991 Turbo S would be a straight monster on MPSC 2. It really would kill the market for the GT2 as Porsche would have a hard time making the GT2 faster. Now they just give you the car, and if you want the tires, you go buy some and take over the track.[/QUOTE]

This is exactly my plan with the TTS. Once the MPSC2 are out (only 2 funky sizes available on tirerack.com), I'll try a set and see what difference in lap times, min speeds, etc, I can get. The GT3 is two seconds faster than the TTS on the ring, so if in a (significantly) shorter track, if they shave 1-2 secs, I would think it would be safe to assume that the TTS will be much faster.

wanna911

I would bet at least 1.5-2 seconds on a 2 mile course, especially if you get a good alignment to make use of them, though I don't know how that will work with the RWS.

reidry

Has anyone see the factory recommended alignment specifications for the GT3? Do they have separate alignment specifications for primarily street use and primarily track use?

Any insider information on maximum attainable camber with stock parts?

Ryan

SamFromTX

That is my concern too, because my mechanic wanted me to put Trofeo R on the TTS and add negative camber but I am not gonna let him because of the RWS, until I see what alignment specs are on the GT3. I realize there is a 400lb weight and other mechanical differences that would dictate the alignment but at least see if it is simply more negative camber on the 3 or more involved.

wanna911

Good idea. I think the reason Porsche is discouraging slicks on the GT3's is due to the sensitivity of slicks combined with the contact patch usage of RWS. I think the rear wheels turning all sorts of ways puts too much heat into the edges of slicks causing tire failures. Having had numerous slick failures myself due to geometry issues related to toe (and fixed by correcting toe geometry), it's a dangerous situation.

Added negative camber will increase the effect. So you could effectively super heat an edge of a tire and cause it to fail. Though DOT slicks like hoosiers and dot R comps like MPSC are much MUCH less prone to this failure (short term).

However, you should be ok to add camber in front, which will still help turn-in. Even still, just slapping them on there will result in an immediate 1 second and some change. Don't forget, braking is increased as well as cornering grip, lots of time gained there also. You just have to use it by staying on the throttle longer into the braking zone.

SamFromTX

Good information, thank you.

Petevb

Pirelli constantly updates the PZero without changing the name. The tires you buy now have nothing to do with the PZeros of a decade ago. More than that, they will use both special compounds and constructions for particular tires, so one current generation PZero may have little to do with another. The TTS likely got a PZero with the latest tech, something between a regular PZero and a Trofeo.

Given this the TTS might not be leaving as much on the table with tires as you'd expect.

Hoopumpers

That's good to know and makes sense. Had a new set recently on my DBS and they were lousy in comparison with even pedestrian MPSS tires on same car.

wanna911

Something between a PZero and a Trofeo is a Corsa, which aren't even all that good. They are not that. They are plain street tires. Huge gap to an MPSC, that you can count on.

Petevb

An acquaintance tests and tunes for one of the big three. As part of his program he tested summer tires a few years ago, roughly 265 through 305. One of the surprising things he found was that in PS2s, the 265 (OE BMW M3) was significantly sticker than the 285 (OE BMW M5). Michelin had used different compounds and constructions for each to suit the manufacturer's requirements.

Competition to land an OE tire contract like the Turbo S is pretty hot, and tire manufactures are going to produce whatever the Porsche wants, regardless of what it says on the tin, using the latest compounds and construction. Not four year old Corsa tech. Thus it's hard to know what they decided to go with in this case, but sweeper cornering speeds were significantly lower than the GT3, suggesting they are significantly less sticky than the MPSC2 at least.

Sam, you might throw a set of those on- they should work pretty well on the TS, as they were designed with similar weights, etc in mind. They'd likely match the car better than the Trofeo.

wanna911

Corsa has new compounds too, which still aren't great, but come on the new Vipers, one of which broke the Laguna Seca lap lap record on them (1:33). Pirelli has upgraded all of it's tire models, the Corsas, the Trofeo which actually did come with a name change and yes probably the P Zero. But they are still going to be short of a good R-Comp like an MPSC.

The Dunlops that come on the GT3 are one set of tires that have proven (on the GT-R at least) to be as fast as R-compound rubber (R888) in back to back tests with pro drivers. I'm not saying it can't be done, but it's highly unlikely given the work that Pirelli put into the Corsa and Trofeo to undercut them both with the PZero. The contract may be hot, but we know that Porsche is not looking for max circuit performance from the Turbo, so they need not provide too much lateral grip.

Porsche is just fine with some good long lasting, quiet, comfy street tires (that can launch 0-60 real fast) on the Turbo. Otherwise, they would have had some MPSC or Dunlops as an option. You can bet they will be an option/standard on the GT2.

I actually like PZero's, have turned some fast times on them, but still several seconds slower than MPSC, which have also improved. Of course I don't know how the N-spec MPSC 2 will compare to old Nspec MPSC and non Nspec MPSC (the latter of which were magic!).