hlee1169

Thanks for the compliment. The OZ Superforgiata also comes in black, which could hide the brake dust better, but I thought the light gray would match my color better. But the most important thing is that they are light.

hlee1169

A quick update, just came back from 2 track days at Thunderhill.

The PSS did pretty well, progressive when traction was lost, and gave plenty of audible warning. The car's on-board G-meter was registering a max of 1.28G on lateral acceleration, and 1.2G on braking.

However, the pressure at peak temperature must be managed. First day I was keeping front at 32~33 and rear 34~35 while hot, and I had a good day. Second day the weather was cooler, and I was not as aggressive in reducing the pressure, and had a bad session where the front tires were squirming under braking and pushing while on the line, a bit scary. When I checked the pressure right after coming off the track, the front was almost 40, and rear over 40. After I reduced them, they felt better in later sessions, although not matching the peak performance of the first day.

I feel that street tires like PSS are great on street with aggressive driving style, but high temperature at track still make them squirmy. Looks like I might need to invest in a set of R888 or Nitto NT01, from talking to the Porsche drivers at the track.

And the difference in tires made a big impression on me because in my beginner's group, there is a brand new Mustang BOSS that was simply faster than me on corners. At straightway the acceleration of my car and his were about the same. I learned that the Mustang is made for track, with 444HP V8, 3600lbs curb weight, and 255/40/19 front, 285/35/19 rear Piralli Corsa tires. I have 245/40/19 front and 295/35/19 Michelen PSS, and I could not keep up with him at corners.

Slippery slope, indeed.

Henry

chuckbdc

GT3.

hlee1169

You are probably the 3rd or 4th person with this advice.

chuckbdc

Well, it is certainly possible to fiddle continuously with your 991 Cab- which was not designed to compete with cars that were optimized to work well on the track, to make it competative.

But I think you will find that seat time and instruction will get you 70% of the total gain possible with any reasonable mods that you will ever make to it. Another 20% is available just from lowering the center of gravity and optimizing suspensions settings. The last 10% is not avalable in a Cab unless you strip it and stiffen it up beyond reason.

If you really are serious about going fast, a dedicated track car will cost you less in the long run, be more reliable and most importantly, be safer immediately. The stock GT3 is Porsche's version of a beginer-serious track car. Just keep in mind that can find Boxter and Cayman Ss running with them at most DEs where there are serious drivers.

hlee1169

Chuck, I agree with you 100%. I bought the cab before I got interested in DE, but I think I am not planning to go hardcore. I want to be able to drive the car to the limit, yet still enjoy leisurely top down cruising. My MPG on track is 9, and on the way home I got 27.4. I'm perfectly happy with this dual personality of 991.

Henry

Sujan Patel

Wheels look great! I'm thinking about replacing my 20's as well as I go to the track often.

What tire pressure are you running on the 20 in stock wheels at the track?

Are you going to any track days in the near future? I'll be a laguna this weekend

hlee1169

When I ran the OEM 20" at Thunderhill, I tried it to keep the front around 32~33 psi hot, and rear 35 psi hot. The ambient temperature was around 90F. After that I have the 19" OZ mounted.

I just did another day at Laguna Seca on Saturday, and one day at Thunderhill on Monday. The 991 handles beautifully, and the Michelen PSS held up well after 6 track days. My best lap at Laguna is 1:54 (in 3rd gear all lap to limit my speed), and best lap at Thunderhill is 2:20. This should give you an idea how hard (probably about 7/10) I was pushing the car.

I started to use a pyrometer to measure the tire temperature as I found it giving me a better idea how I should adjust the tire pressure just right after a session ends. At Thunderhill I was running 35 front and 38 rear hot on the 19" PSS with ambient temperature around 80F.

I got a lot of compliments on the factory sports exhaust, they said it is one of the best exhaust sound they heard on the track, and I totally agree!

I might sign up for Laguna Seca on Sunday, 11/4, with TrackMasters, and have already signed up for Laguan Seca in November with PCA-Diablo and PCA-GGR for a total of 3 days!

Sujan Patel

@hlee1169 Thanks for the rundown. I've only had 1 track day in the 991s and was running 32 psi hot in the front and 38 psi in the rear. I didn't really touch any settings as I was unfamiliar with the car and ran the course in reverse. I'll play around with it the next time I go to the track and try your temps.

I'll be at laguna on 11/4 & 11/14 would love to see the wheels in person. Pm if you end up going.

BTW do you get loud vibration noise when you're going 80mph and above? Here's a video of my track session: http://www.youtube.com/watch?v=trixI...ature=youtu.be

The noise is really annoying/distracting and makes me want to stay under 80.

hlee1169

hmmm...I can't tell what the noise is, sounds like something flapping?

Here's mine at Laguna Seca, with instructor with me. I kept it in 3rd gear for the whole lap because I did not want to hit the walls. As you can see, no weird noise above 80.

If you going to Laguna Seca on 11/4, it must be Track Master, right?

Sujan Patel

it's not a flapping noise..sounds weird on video but its the same noise as when you have 1 window open in a two door car..I'll call the dealer

Yes it's through trackmasters

Detroit Shooter

I did a Skip Barber 5 day open wheel Race School years ago, it was awesome. Won't forget that track any time soon. Love to take my car around it. You sound like you were having fun.

mdrums

Really nice! Sounds like you had a good instructor too. Have fun!

hlee1169

Thanks! Laguna Seca is a lot of fun, and I definitely have respect for the track since the walls are quite close in a lot of corners.

Yes, I have signed up for the Track Master's Sunday event at Laguna Seca, so Sujan you can drop by to check out the wheels.

n17mm

Nice looking wheels for your car. The net weight difference is impressive.
Looking at your tires from the pic, it does not look like they were shaved.
Last year I bought the PSS tires for a 997 GT3 from Tire Rack. My sales rep asked if I would be tracking the tires and I said yes. He indicated that I should have them shaved by Tire Rack, relatively minimal cost. I think they take off about 60% of the tread. When I asked him why I would want to throw away 60% of the rubber that I was paying for, he spoke of a simple thought. Imagine taking a new pencil and using it aggressively on a piece of paper. It will squirm quite a lot and wear at the edges first and hardest. Then imagine cutting off the top 60% of the eraser and you can see how much less the eraser moves under load. His claim was that the shaved tire would actually give more miles at the track..

Can't give you my personal experience as I sold the car before taking it to the track. I am awaiting my 991 to be delivered after a Euro pickup.

Did the Tire Rack rep mention this to you?

Fred S