johnsopa

OK, here is the video from one of my sessions at NJMP Thunderbolt yesterday.


Stock GT4 with Michelin Pilot Sport Cup 2 tires that are almost completely worn out. No mods, stock alignment as delivered.

Lap 1: 2:25.599
Lap 2: 1:31.997
Lap 3: 1:31.691
Lap 4: 1:32.216
Lap 5: 1:31.618
Lap 6: 1:32.287
Lap 7: 1:32.007
Lap 8: 1:31.935
Lap 9: 1:31.500 (fastest lap)

Apologies in advance for the lousy sound quality (I hooked up my external mic but for some reason the SmartyCam didn't use it) and also for not having any ECU data. This AIM setup is not nearly as intuitive as the barebones iPhone Harry's Lap Timer app. See some of my AIM questions here: https://rennlist.com/forums/data-acq...questions.html

It's also the first time I've uploaded anything to YouTube. Let me know if you have any questions

jphughan

I don't time myself, but a passenger timed me today at CotA on one lap during my first session of the day just using his stopwatch operated by hand. Turned in a 2:34, on Cup 2s with -2.5 F and -2.0 R through Tarett bits, Castrol SRF, everything else stock, and obviously a passenger. I'll take it.

doba_s

Chris how much chatter do you get from LWFW? Does it make sence upgrading it?

Nur93

Great thread, but I would say there Is One major track missing.
We (outside USA) in the EU dont know much about these tracks

But Nurburgring is a kind of world reference in terms of laptimes and all on the planet soner or later end up here anyway. All carmakers do the #who can **** the longer contest here# so why is it not on the list then. If SPA is on Nur must be on

ChrisF

It chatters a bit; similar to 997 RS.

Worth it? I'm mixed. If I had to do over probably not. It was easy to do when diff was out so I did it to try.

matttheboatman

Nur93, so true! Would you please submit for me to post your best Nurburgring lap time so that I will have your permission to post it to the list of Best Track times in a GT4. Will need the date, tires, and if any mods to the stock car.

matttheboatman

Added to the Best Times list, nice driving John

Updated, thank you for submitting your times!

Updated, nice time with passenger!

Terry L

Lightning (NJMP) 1:16.0. All stock. 2.5 degrees front camber, 1.5 rear. Pagid T3 pads, SRF fluid. Front tires badly worn in centers.

Nur93

Sweet, my lap is accelerating btg start right from pit and its that year 2015 that will go to history as it was speed limit on long straight, flugplatz and SwedenX. All info on car is in description, but car is stock. Laptime 7.30 BTG

matttheboatman

Got it posted. Yes, that was wicked quick lap Nur93!

Nur93

Thanks!

Was very keen on geting down there in GT4 this year and cut 3-5 seconds. Tracks is faster and more easy now when they made a new flugplatz section. But I go in M4 GTS later in sep instead. But damn I would Love to try GT4 with real propper camber setting( like not stock but with toe bars etc, that would be more fun and easy for sure)


For your info my car was stock on stock Michelin cup2 tire. Brake fluid was endless and RSL Yellow Pagid pads.

-2 front and 1-6 rear camber

24Chromium

Tires on my car for laps at Nordschleife and Spa were MPSC2s.

matttheboatman

Ok, fixed it! It seems to be the consensus that the Dunlops are both slightly faster than the MPSC2s on the track (and faster to wear out too).

Manifold

To put some data out there for Summit Point, I heard that TPC Racing was seeing about 1:22 with pros driving the GT4 in stock form, and about 1:20 flat after modifying the setup of the car, including using their DSC controller.

For comparison, my best time in the 991 GT3 at Summit Point is about 1:20 flat, and TPC Racing did low 18s with a pro driver in their GT3, which has some mods to the setup and their DSC controller.

TPC has also told me that, to optimize the setup, the GT4 needs more adjustment (relative to stock form) than the GT3 does.

Once both cars are fairly optimized, the delta between the cars appears to be about 2 s at this track (not really a 'power track', IMO). That's substantial, but not huge when you consider that the lap times for a guy like me can vary by 2 s or more depending on how hard I'm pushing, condition of the tires, track temps, etc.

These lap times are all with the Cup 2 tires.

TPC Racing

+1

We have found the GT3 to be an amazing track set up from the factory. Porsche really outdid themselves on this one. As much as we'd love to sell a bunch of parts for such a great track car, as of now our biggest recommendation is a set of the side muffler bypass pipes to reduce that weight and heat from the rear tires. We do have a set that retains the factory valve for sound control and the flex joint for durability/reliability. Then, of course, the DSC Sport V2 controller really helps fine tune the damping, and you can always tune to your liking.

As far as the GT4 is concerned, when Randy Pobst was putting down the 1:20s at Summit Point (bear in mind these were unofficial hand times), the car was still mostly stock. It featured our Stage 2 suspension package for the GT4, which consists of our just-released TPC Racing Offset Toe Rods, DSC Sport V2 Controller, and our proprietary alignment specs intended for use with the toe rods and controller. You can find more about how we developed this package here:

https://rennlist.com/forums/gt4/9404...acing-gt4.html