Inrev

Hi,

I'm a DE enthusiast and have been doing DE events for the past 12 years now. Most of my experience comes from mid-engine cars and my last track toy was a GT4 with slight suspension mods. I decided this year to switch to a 991.2 S after realizing I barely drove the GT4 because I have small kids in a shared custody agreement, so most days it just sat gathering dust in my garage. I sold the GT4 and bought a slightly used 991.2S with the following options: SPASM, RAS, PDK, SC and glass sunroof.
For track duty I had an aggressive alignment done and added Ferodo DS11.1 pads with castrol SRF fluid.

I made the mistake of thinking wheel width in the back was 11in and ordered some Bridgestone Potenza RE-71Rs in 295/30/20. They looked a bit stretched but figured now that they're here might as well try them.

So last week I spent 2 days at Calabogie, a technical track famous for killing tires. Best track time was in the 2:22 range, same as with the GT4 before the suspension mods. Then I dropped to 2:21 with the suspension mods. Not bad at all for a car I haven't had much seat time in yet. I kept pace with the 991.2 GT3s and Turbos so not too shabby.

My impressions compared to the GT4 are as follows:

Pro:
The engine. The torque is phenomenal and it made me a believer in turbocharging as the future of performance. As your throttle input increases you feel the engine pushing you from behind and it's addictive. Corners I used to hate in the GT4 were pure joy in this car!
The engine placement: this might be a bit controversial, but I felt a bit bored with the mid-engine layout. So to me, trying to get the most out of a rear-engine setup is a fun challenge. I like the fact that you need to change corner entry and exit to maximize traction coming out of the turn instead of keeping as much speed as possible like in a momentum car. While mid-engine is where balance and corner speed is, I really liked the added challenge and reward of the rear engine layout.
SPASM: a very good suspension setup with good predictability coming out of corners. I would say a bit soft still but for a daily driver it's a good compromise.
PDK + SC: I'm not sure if it's a pro or a con, part of me misses the third pedal, but one thing for sure is that PDK is very good. There is one or 2 turns where it would stay in higher gear then kick down when I accelerated out of corner where I would've liked it to come down a gear before the turn and be in the right gear at exit. Then again some corners I probably slowed down while coasting.
Brake costs: The GT4, having GT3 brakes, was pricy when getting pads and rotors. The 991.2 S is more reasonable.
Kid seats in the back: I mean come on, how cool is it that I can chase GT4s and GT3s around a track with the kid seats still installed in the back seats!

Cons:
The engine sound: The GT4 sounds awesome at full throttle. As I passed GT4s on the track I couldn't help but envy that sound.
The weight: Car felt heavier in the turns and I had to brake earlier. I rewatched videos of the GT4 and man does it keep speed in the corners!
Balance: GT4 was easier to drive because it felt so balanced all the time. Not keeping as much speed through corners in the 911 was frustrating at first.
Brakes: let's face it, the 991.2 S has great brakes but not quite to the level of the GT4. I had to brake earlier than in the GT4 or else I would overshoot the turns. Probably has something to do with the added weight too. Wider front tires might help too.
Tire wear: I killed the RE-71s in the back in 11x 30 minute sessions. At the end I had trouble putting the power down and the car was getting tail happy on corner exits. Nothing I couldn't handle and it was still fun but no way was I gonna beat my best lap of the previous day. They are almost bald now while the fronts look good. Some trial and error with pressure probably accelerated that wear but still... In the GT4, tires would wear about evenly to the 4 corners. I would do about 24x 30 min sessions with a set, if I flipped them mid-life. The 991.2 gave me 11x sessions in the back. Ouch.
Tire cost: The RE-71Rs are a great budget tire and were my go-to brand when I had the GT4. However I think for the rear engine layout of the 991.2, the 295 size may be a bit skinny and 305 or more may be in order. The only streetable track tire in 305 I could find was the Sport Cup 2 (I refuse to ever buy Dunlops again) and those are pricey. But if they wear slower in the back they may be worth it in the end.
PSM: a bit too intrusive, wish it had the 2 step nanny removal like in the GT4 and GT3. GT4 allowed more play before intervening.

So what's next?

First I need track wheels and figure out a good tire setup for the car with the right pressures. The RE-71R, while cheap, is a bit skinny in the back and I felt that it held me back powering out of corners. I will try a 305 and report back. If they wear slower they will make the RE-71R a non-issue.
Then I need to find a better brake pad than the Ferodo DS11.1. It's great on the track but now my car sounds like a train when coming to a full stop. While it didn't bother me in the GT4, in a daily driver it's a bit more annoying. When they wear out I'll look for something a bit less extreme.
Then looking for easy mods to do that won't sacrifice daily driveability and will be easy to revert to stock next year when I move to a 992.

So... any comments and tips? I found finding information on tracked 991.2 cars is hard on this forum because of the sheer volume of threads whereas it was a lot easier in the GT4 or GT3 forums. I think the 991 forum has enough population that it should have its own track sub-forum, especially since those cars are different in many ways from the GT3s.

erko1905

Not sure about daily drivability or whether it'd be considered easy mods but these are a few items that'd be next, not necessarily in this order:
- More camber from LCAs or camber plates, or both + maybe caster pucks depending on what kind of caster you like/clearance you get. (ride would be a bit harsher due to reduced rubber, but turn in, corner speeds, tire wear really improve)
- Seats+cage+harness (probably not for you since you want real seats operational)
- Cobb tune+headers (seems reversible, comes w its risks)
- DSC Sport PASM controller (easy) OR coilovers (not so easy, or cheap) OR some other suspension coolness (really no end to suspension stuff, I doubt you'd want to go deep into that pool)

Technically everything is reversible but I wouldn't call any of these easy mods, if you're getting a 992 next year anyways it's probably simplest to not mod. These cars put down solid laptimes out of the box.

245/305 Cup2s work, I wouldn't bother w 295 rears.

A good mod would be to teach yourself left foot breaking if car is PDK and you're not doing it already. It really improves your break to throttle and back transitions.

arter

If you switch to 19's you can get 71Rs in 305 for the rear. Plus they would be cheaper than the 20s.
I would expect that 71R will wear longer than cup2's. sorry.

Inrev

Can't do 19in wheels because of rear axle steering unfortunately. I've bought rear replacements for the RE71Rs, once all 4 corners are toast I'll try the Cup2s and will see. If lap times don't improve it'll be quite interesting.

I want to try left foot braking but not sure when to use it!

arter

I have RWS on my 991.2 GTS and I run OZ HLT 19s on it. You just need to get the
et50's or add a shim to the rear tires if you buy the ET 40s ( I did).

You can also try the Trofeo R's ( in 19 cheaper than 20 cups 2).

Inrev

tstafford

Worst part of the 991.2 as a track car (IMHO) is the insane rate at which it eats up tires. I'm sure with suspension mods we could get more neg. camber but I don't want to screw around with it as it's mostly my "showing people the track" car and weekend driver.

I'm with you on most of the other comments esp. the belief in the turbo.

Mark993TT

Inrev

Thanks I'll check. Seems to be just 1 step on mine, on or off.

Mark993TT

arter

Go to tirerack, put in your car model, lie about having RWS, and it will suggest 19 inch OZ wheels as one of the options. 11x19 ET50s will work. Does have a close gap so you have to watch where they put wheel weights.
Alignment doesnt effect rim/suspension gaps, just offset.

Inrev

Thanks I'll check. Seems to be just 1 step on mine, on or off.

arter

just push it quickly and you should get sport psm

Inrev

Site only gives me ET65 offset so I don't think it will work. Do you have a closeup of your wheels?

I tested PSM and indeed it has a sport option so I'll try that at the track next time!

Inrev

Ok so I checked and the GTS can get the ET50mm offset in the back, probably a wide body thing. Guess I'll have to stick to 20s