Ray G

I did my 2nd dry track day in my GT3. I had very poor grip from the rear OE tires. I only have about 2400 miles on the car. I had the race school owner (a veteran 911 cup racer) drive it, and his words "The car is wonderful, but there is just NO GRIP". I can't get onto the throttle until I'm straight. It felt like greasy tires that are going off. It was very disappointing. My alignment was done to be "aggressive street". I tried all different pressures in the rear: 31, 32, 34, 38. Basically terrible no matter what.

Has anybody had rear grip problems? I vaguely remember reading either a review or a post complaining about the lack of grip on the new GT3. Not sure.

I'm having the alignment looked at again, and I guess I will order a new set of MPSCs.

Shark-GT3

Ray,

Did Kitch have any suggestions? What tires do they run on their Team Seattle cars?
Do you feel it is the tires or your set-up?

Is colin doing your alignment?

My car arrives in Sept. (or so) and I hope to get 1-2 track days in before the frost. I would enjoy learning from your experiences prior to its arrival.

When will your 3rd track day be?

Brian
www.sharkstainless.com

Bob Rouleau

Ray - while the 19 inch tires do not have as much grip as the 18 inch Cups, I would be suspicious of alignment. Perhaps your settings got knocked loose. My experience is that the new GT3s have massive understeer and I aligned mine to dial it out. It takes a rather brutal mash of the gas pedal to get the back end loose on my car as well as those of Apex Late and Racerron.

Best,

997gt3north

- were those cold tire tempts or hot?
- i have had good success at 34-35psi hot in the rear
- i have had the car at Limerock (cold weather - April/May). VIR (hot in May), Watkins (warm - June), Calabogie (hot - June) and I would describe the rear end grip as good
- the exception to this is in low speed sweepers if the tires get hot (VIR #1 on exit, VIR #5a, limerock #2 in the rain, exit of the TOE at Watkins, exit of Gilles at Callagogie, The Beak at Calagogie)
- I run full rear wing this should help as I want as much grip as possible (but at slow speeds (slow sweepers) it clearly doesn't help much) - I do think a bigger wing with maybe less rear bar would be a better setup?

doc2s

check alignment, sway bar settings, and ride height. mine came 11mm higher than stock in the front.

Ray G

Thanks for feedback, guys. The tire pressures I gave were hot temps. The car has been corner balanced and should be setup nicely.

I ordered a new set of tires and the car will go in for a new alignment, perhaps with the recommended "track alignment" this time.


No Don didn't have any suggestions, but he did about 10 laps trying different things. He spun it once (T8), and I spun once (3B)! (and I never spun my 996 GT3). Colin Cantrell does all my work. I noticed since the car was new, that the rear end broke loose very easily just driving on the street. Maybe I got a bad set of tires or something.

Congrats on getting a new car. I'm sure you will love it. I'm not sure yet when I will track again - I usually take the Exige to the track. But I will be out there again to test the new setup.

Ray G

One other question: Are there 2 types of Michelin "cup" tires that will fit? That is, the "N-spec" vs. regular cups? Has anybody tried the regular cups?

Shark-GT3

Thanks Ray,
Good Luck with the set-up.

If you think about it, please P.M. me next time you are planning to head out to the track.

After a 14 month wait with no guarantee's, I am pretty excited.

Brian
www.sharkstainless.com

997gt3north

- track settings should make a difference but the inside of the rears will wear quickly at -2.5 camber
- i have also spun the car (turn #1 at VIR on exit) - in hindsight I was pinching the exit as i gave it throttle but you have to learn to use a delicate throttle on tight corner exits or the rear will absolutely come around if you still have any significant amount of stearing angle (you must reduce the stearing imput as you give it gas on exit)

doc2s

the regular cups have more dry grip and less wet grip but don't come in the 305/30/19 size.

sasportas

Consider changing the rear sway bar to full soft - seems to gain tremendous grip. Also, the rear is very sensitive to tire pres - I agree with the 34-35 - any higher and the rear will step-up quite a bit.

mooty

ray, i have factory rec track setting 2/2.5 neg.
although my rear isn't twitchy or loose, it didn't have much grip either.
speaking with grussel and based on description from bob r, my guess is that's normal for the oem tires. i am waiting to get some 18" to play in the near future. if i ever figure out what to do with the other car.

Ray G

Hmm. That's interesting... and disappointing. I plan to set mine to the recommended track settings in the manual so we have a known starting point.

I think you are the first person other than myself to say they had rear traction issues.

Maybe 18 inchers are in my future.

NoSubEDU

What's amazing to me is how the EVO mag videos and some of the other tests resulted in such high ratings for the car. I am assuming they were using OEM tire/wheel combos. I have yet to take mine to the track so I will withhold my "official" comment until I do so.

GlennMc

Silly question, but you did you go on track with any of this tyre sidewall black stuff ??

Some of these products are silicone based, and i have known of guys that have all kinds of weird handling when cornering hard, as some of the product can get onto the contact patch.

My rear end is as planted as hell, only the front that drifts...


G.