porsche_love

Good info shared by track guys here. I have taken my previous e92 M3 to the track a few times but I have yet to take my C2S to the track. Other than covering the basics (SS brake lines, pads/rotos, tires), the 991 seem to be pretty solid for occasional track days. I am looking forward to it. Thank you all for sharing helpful info.

sanjeev

Hello,
I noticed that someone mentioned running 19" tires in 255F and 305R sizes. Couple of questions -
1. Since these are not the factory 19" tire sizes (which are 235F and 285R for C2 models), which dash setup do you use for setting the tire diameters? (I.e. The 19" or 20" settings)
2. Have you noticed any ABS or PSM issues or error codes?
Coming from a 997 previously, there was a suspicion that using tire diameters other than the factory setup could cause ABS or PSM issues - the infamous "ice mode" brake feel.

Please let me know if you always disable PSM when using these tires. Or if not, have you experienced any PSM issues?

THanks,
- Sanjeev

RonD

I bought the rear rotors thru Amazon. Sols Brake Supply. Search "Sebro Sport Slot" Part # for 991.1S are 909323 and 909324. You would want to confirm your 2017 .2 uses the same rotor as the 991.1. Probably best to call the listed vendor and confirm part # before you order.

Leecw

Thanks for the feedback

boatracer

how loud are the RS 29 pads off the track? Use mine as a DD and want a better pad, but one that works reasonably as a DD. Maybe asking too much....

BradB

They are pretty squeaky. I once scared a lady in a crosswalk into thinking she was about to be hit by a bus. That squeaky. Seriously, not ALL the time, but often. IMO, you can't have it all. I change my pads for every track event.

erko1905

Gonna try Ferodo DS2500 w the same hopes - will post if that's successful

FLACHT6_pilot

I'm been tracking for 20 yrs, but mostly in BMWs.

I just took my '14 991S to the track for the first time. Prior to going I put on some Girodisk front rotors. The rotors were sized in a a way that allows me to use 991 GT3 sized pads (they drop right into the front calipers). I went with some stock GT3 pads and they worked out fine for two days of tracking at Watkins Glen in the instructor group. The didn't have the bite of true race pads, but lasted just fine with no fade.

I did some some high oil temps on extended (30mins +) runs. I saw up 270F on the oil and will be installing a 3rd radiator before the next trip to the track.

All things considered it is a great track car right out of the box....Porsche did a great job with the 991!

BradB

BTW, I use Mobil 1 5w50 oil on the track. Makes me feel better than using the standard issue 0W40.

RonD

I have the 255/35/19 and 305/30/19 RE71R tires on order. It’s my understanding and confirmed with my shop, the front to rear diameter difference is what matters. The speedo may be off slightly, but shouldn't have any issues with ABS, PSM etc.

The OE tires are 26.8” front and 27.0” rear diameter and the RE71R are 26.0 and 26.2. Both with the same .2 difference front to rear.

So I’ll give them a try and report back with the performance and if I have any issues.

hsmith

991 is excellent on track. I track my GTS and the only thing i changed is the brake fluid/(SRF) and tires (PSC2's). I have PCCB and they are incredible on track. No noticeable wear after 8 or so track days. I'm planning my first track day of the season on the 22nd. Can't wait for some Lime Rock action.

sanjeev

Thanks. I will look forward to your post on how the 255/305 tires work out.
- Sanjeev

Rambler_13

I just had all 4 tires replaced with the Pilot 4S's and also put in the Pagid RS 29s. Yes, they squeal. What I have found in the past is that if you have the ability to warm them up and do a few moderate to hard stops, it lessons the squeal for a while. Problem is on a daily commute, it's sometimes impossible to that that. I never had the yellows before and didn't' realize they could easily be seen behind the caliper. I think they look kind of cool sticking out behind the red calipers. Even though my rotors aren't carbon ceramic, apparently my driveway is, lol.

RonD

How much negative camber did you get with the GT3 lower control arms?
Did you add shims?

Thanks

GT3_Driver

...Want to know this.^^^^

I am about to get an "Track" alignment

I imagine Toe is the only thing that can be changed very much when stock.