Warwick Morris

I need some advice on tyres. I'm in Australia and bought my road-registered GT4 with clubsport pack principally for club-level motorsport and to drive to and from the track. The car was delivered with MPS Cup2's and I've now clocked up about 3000kms with a number of track days, test days and events. The car has RSS toe links and runs 3.00 neg F and 2.75 neg R. I have to say the lateral grip is quite disappointing and the car is a good deal slower than my 1999 996.1 GT3 with all data showing the time is lost in corner speed (and lateral G). The old girl (GT3) runs Yoko AO50's which are the "gun" tyre down in Australia. Unfortunately they are only made in max 18" rim size and even 19" you're really limited to Toyo R888 (or now R888R).
What do other people do to make this car competitive in mixed company when you're running against 996/997 GT3's? I am looking at 19" wheels and Toyos but also considering a change to previous gen GT3 front brake callipers and 18" wheels where the tyre choice is quite wide. Has anyone got down that route? Also does anyone know of rumours of a decent track tyre in 20" on the horizon?....given the number of Porsches now running 20"s there surely must be demand.

digitalrurouni

That is quite interesting about the lateral G and time being lost in corners with that much camber on your car. Question what sort of lateral Gs are your numbers showing btw? I am curious

I think the only track tires I am aware of are the Trofeo R from Pirelli and the Bridgestone RE-71R I believe in 20 inch trim.

GrantG

Hoosier R7 are due to come in 20" sizes soon, afaik.

Also, I think you may need to make provisions to maintain caster with that much camber (pucks, thrust arm bearings, etc.) and the general rule of thumb is to have .5 degrees more negative camber in front that rear (your setup with only .25 degree difference could promote understeer which is already an issue with the car stock).

Lastly, the GT4 does require a different driving technique than 911's (if that is your experience) to maximize pace - faster entry speeds than what is comfortable with a 911...

ExMB

The RE-71R aren't really listed as "track tires" per se even so they have proven themselves to be comparable to the MPSC2s.

O5C4R

Dunlop sport maxx race are quick tyres but the fronts wear out really fast
The new ADO8R's come in 19's now and seem to be much better then the original
some other Aussie mentioned that the 20" Pirelli trofeos are also very quick but crazy expensive

nothing other than slicks will come close to the A050 however, they are way better then anything else

MC 968CS

Hi Warwick. On the 997 GT3 i tried both AO50 (m) and Trofeo R (19") and found the trofeo very close. I was actually faster at Phillip Isl on the Trofeo R then the Yoko if that helps. Pressure setting takes some getting used too, as the Trofeo R like around 29psi hot, max. If I was in a GT4, that is the rubber I'd run.

I know some guys don't rate them, but i don't see why - seemed good to me. Trofeo R seemed a good fast semi - treadware is only 80 so you use them up...but hey i now only get around 3-3.5 meets from the Yoko anyway before rears are bald.....

One factor....Troefo R were expensive vs the Yoko, hence running Yoko since myself, however...yoko are now much dearer than they were 2 years ago so thats now old news.

Warwick Morris

Mark, I've taken all this on board and I've reserved some Trofeo R's'.......fronts are available but rears are on the water but hopefully available before the first PCNSW meet. Grant Geelan told me Friday that he understands some new 20" R Specs should be available this year (I think they'll be Toyo R888R). The Hoosier's are not permitted in our competitions; they get classified as slicks....at least that used to be the case. Also I need to learn a bit of a new driving style as GrantG from Denver says....bit of a challenge and so I'll look forward to it.
Busy time coming up with the Dave Thomas Victorian high country 3 day blast then the serious comps begin!

francis_william

Trofeo R, what else =D

Snowman.

Warwick - you know Mark and I both run the Trofeo R's. Hard part recently has been getting hold of any as Holden have been pinching all rears stock coming in for their new HSV GTS-R. I've had a set on order for 6 months now and still don't have them although I'm told 6 sets are coming in shortly.

Only positive is this new OEM demand means the local price is going to be better.

But they are quick. You know we've done 28's at Bathurst, 42's at SMSP and 45's at PI on these tyres in otherwise pretty standard cars (just headers and alignment).

The issue with the R888's in 20's is they haven't been making them to suit the fronts for a GT4. They were really designed for the R35's etc with the narrowest 20" being a 285's which are way too big for fronts.

GTS_Ninja

GT4 w clubsport package?

Never heard of this. I don't think we get it in North America.

Do you mean the GT4 Clubsport? the factory caged PDK car?

O5C4R

1.42 in a GT4 at SMSP is verrrrrry fast

.dee

that sounds right for a well driven car on R's and headers.

I did 46's in a stock car (track alignment only) in a 46 degree day I think Warrick runs similar times in a stock car.

Snowman.

The rest of the world minus USA could get a Clubsport package which consisted of a half roll cage, carbon bucket seats, fire extinguisher and 6 point harnesses. Mine has the same thing. But otherwise they were the same car.

Ypu can even option up the front part of the cage as well - you can see from the pic the mounts come prepared as well as mounts in the front footwells for the front part of the cage. But it was $$$$$$$$$ for the front part!!!!

O5C4R

jebus, I need some trofeo's and a boot up the **** to improve on my high 1.47

Snowman.

At Phillip Island we went from 48.3 to 45.0 with Trofeo's over Cup2s.

But one thing to note - they do drop off in performance and that is the complaint from most people.

Mark at Bathurst this year was doing 30's on a set that had done a few track days and then did a 28.0 on a brand new set the 2nd day. But even when they start to drop off they are still better than Cup2s.