slvr993

You are dead right - there are a lot of us. For some it's less flash and for others its not having a car thats really streetable ( not just tolerable) and capable at the track with all GT3's and GT4s that are there.
This is the future no doubt. This 991.2 is my 14th P-car - dedicated race cars, dual purpose cars and street cars. As much as I love a good NA motor like the next guy, after only two weeks of owning this car its easy to see this is the future. The torque makes these motors a lot of fun on the street and the tune-ability and Rear Wheel Steering allows base / S / GTS models to run with the biggest NA cars with relatively cheap mods. On the street my base 991.2 is more fun than my 2016 or 2018 GT3s were and it makes me much less self conscious. I haven't tracked it yet, and those will be big shoes to fill. A PDK GT3 will make you feel like a god on the track - even going 8/10ths. But, with a few add ons, I think the 991.2's will be the best car as an all around toy car. Great street and really potent on the track.

This will be a fun journey. I am subscribed! Third radiator going in.

mdrums

LavaGTS

Sounds like Porsche owes us southern state owners a free kit

BGB Motorsports

Given where we are in the U.S. I recommend that upgrade to anyone in the bottom half of the country that goes on track. In my opinion it's an investment in protecting the car for all environments. Everything is controlled via vacuum operated flappers so if it's 45F out, the ECU closes coolant passages to heat the car faster. When on track it's fully open. The turbos are cooled via engine oil and the engine oil is cooled via the coolant so I'm going to make sure I've exhausted all cooling efforts for track duty. We sell the C&R radiators (formerly PWR) and they're best units in the world; they're on F1 cars, Indy cars, NASCAR cars, etc and if we deem the car needs them, they will get upgraded. I helped them make direct replacement side and center radiators for the 997/987 cars and then the 991/981 cars. They're 100% plug and play and they're crashed tested too! ?

groundhog

Hi BGB - can you outline the stock specification of the test car e.g. does it have RAS and PDCC for example

Cooling - I'm 100% sure you will need as much cooling as you can get if you run hard with the tune. In short events e.g. Targa type stages and sprints (10 to 40kms run at full belt with about half an hour on liason before the next stage) I get up to 248F where the ambient temp is ~ 35 degrees C/ 95F. I have never run out of brakes in these scenarios.

General comments -

(1) with the tune I'm 100% certain you will need a lot more cooling - the turbos will be working hard and theres little point in the tune if timing gets pulled due to temp related events.
(2) with wheel to wheel and longer sprints +25km I think you'll need to upgrade the brakes - no question also no big deal
(3) aero - this is really important - I have found at one track in particular the lack of aero is very obvious specifically - a very high speed left right that has a bump at the point where you transistion and at a high speed straight where you are close to 240kmh and you go over a crest - the car gets light, frighteningly so.
(4) Getting decent tires and wheels that clear the rear steering rams is a problem (although I'm pulling up to 1.6g with MPSC2N1 but still not r spec highs).

The powers great but you'll need rear steering and aero to really deal with the well driven GT3/GT3RS. Out of corners and in straights I can stick with the latest GT3s (if well driven), however they have the edge through corners tho and just get away little by little (if on MPSC2N1).

Following this thread with a great deal of interest.

BGB Motorsports

Hello - It's a 2017 with PDK, no sunroof, 5 lugs and steel brakes. I don't think it has the rear axle steering and to be honest, I am glad it doesn't. That's a nice feature but I've spent many years setting up 911s and Caymans for the track and I know how to find front and rear grip and would just assume do it without active rear control arms. I will look under the car tomorrow and get back to you. As for replies to any comments, before I address them specifically, I am going to absolutely do the intercooler upgrade as well as the center 3rd radiator and then if we need better coolant temps, I might consider going to the upgraded aluminum motorsport oriented radiators. As for the rest...

1.) we are on the same page. the turbos are working harder and the intercoolers will help. I want this thing to be bulletproof on the track as well as the street and Florida race tracks in the spring/summer/fall provide the perfect testing ground for this.
2.) i'm upgrading brake pads, brake lines and going to a more traditional motorsport oriented disc. I will keep the stock discs on til I destroy them, then they will get retired. We sell a lot of Pro Systems brakes and this is the company that provides mated pads/discs for pretty much all of NASCAR. I will start with these and probably go with a compound that does not have a lot of initial bite because it keeps the ABS happy when running sticky tires. I don't like aggressive brake pads on the track because I know that the ABS freaks out when trying to decelerate at anything over 1.1g. I haven't been on track with this car yet but if the ABS programming is anything like any of the cars from the last 10 years, it's still succeptible to the dreaded ice mode/hard pedal. Furthermore, none of the brake master cylinders for the 981/991 have that nice tall pedal feel that we had on the 987/997 cars that ran the upgraded GT3RS brake master cylinder and I plan to finally resolve that as well.
3.) I am a little disappointed this car doesn't have a true aero kit like the 991.1 GTS. We sell a lot of aftermarket stuff but I want to keep this thing looking as OE as possible. If I could, I might try and retrofit the .1 kit but I have begun my internet research because it needs a rear wing for stability for high speed tracks. We go to Daytona, Sebring, Road Atlanta, VIR, etc. and you want the added rear stability.
4.) I will see what we can put on but I know that when we tried to homologate the 991.1 for racing we couldn't clear the toe link with an 18". I will try and put a 19" on the car tomorrow and report back with that as well as to whether or not it has the rear axle steering.

Thank you very much for the feedback and I appreciate the race track related insights; this thread is intended to document what I do to the car but I also want you guys to chime in with feedback because I can advise on solutions for issues you're having.

groundhog

Hi BGB - if you look at the current gen cup cars they run 18s and do not have rear steering - part of the clearance issue is the brakes. The cup cars do not run Brembos but rather PFC supplies brake equipment to Porsche Motorsport for the 991 Cup race car and also the Cayman GT4 race car. Both these cars use the same callipers and the same size discs, but using the V2 mount system on the 991 and the V3 system on the Cayman GT4.

4 Point 0

Hi John,

I am testing Pagid RSL 29. I have fronts getting fitted on Thursday.

I noticed with braided lines, that the C and CS only have a four line setup. Whereas the GT3 & GT4 have a 6 line setup. I understand they change the hard line to add length and make it easier to get caliper on and off.

Does this 6 line setup work with our GTS? Or should we only get the 4 line setup? There doesn't seem to be a specific one for the GTS.

I deliberately never got it as well. If you want pure feedback, you don't need it.
Cheers.

BGB Motorsports

Understood but the issue isn't brake clearance on this car but instead clearance of the lower 2 suspension knuckles. If it were that easy we could just sell the same caliper swap we do for GT4 owners that want to run 18" wheels like we do on our Porsche Club race cars but we have a suspension clearance issue in the back. I have attached a photo below. The GT3 street car and Cup car have different rear uprights and arms than the 991.2 and 991.2 street cars and therefore you cannot run an 18" wheel on track on a 991 street based on-GT machine and even if you found a way to cheat it, it's not safe. The nice thing about us doing this work is that since 2004 we have developed the street car into a professional race car; I've spent over a decade developing parts, finding the right combination of brakes, cooling bits, suspension bits, etc because we were never allowed to start with a GT3 or use GT3 bits because it would have been too fast for our series. I tried to get a 991 homologated for racing 2013 but a 19" racing slick didn't exist for our series and while there were some other factors working against us, ultimately that's what killed it. Similar to the GT4, your only option will be to go to a 19" wheel and even then i need to confirm fitment because it's going to require a decent amount of offset to get the inner barrel far enough away from the lower suspension knuckle to keep me happy; now you're flirting with things sticking out too far beyond the body work so it will require a specific wheel offset. I still need to see a 19" myself on there until i can say 100%. I sold my last set of Forgelines with my GT4 so i don't have any more to test fit.

We started life first as a race team and then moved into the aftermarket world so i have a different approach to things. We have 4 - 5 Clubsports that live here, Cup cars coming and going and tomorrow i'm headed to a private debut of the new GT4 race car. The 718 GT4 test mule is rolling around Florida right now as well. I will give you the straight scoop on the fitment of the wheels the moment i see it and i'm comfortable suggesting it.



991 Lower Rear Suspension Fitment - 18" Wheel with Cayman offset





991 Right Rear Suspension - 18" Wheel


You will like the RSL 29. It has a high ceramic content and is a compound we used for many years because it doesn't shock the ABS and generate the hard brake pedal as much as a pad with a higher initial bite will.

As for brake lines, i would recommend going with the 6 line setup just like what's on the GT3 and GT4 since you have the new style caliper with the bridge and will want as much line length as possible to be able to change pads. My 981 Cayman customers use the 4 line setup but that's because i sell a 997.2 GT3 6-piston caliper setup to them because they want the old style caliper that allows a pad swap without the caliper removal and that runs the 4 brake line setup; they prefer this because it allows them to run 18" wheels on track which is not possible with the GT4 or the 991.

groundhog

Thanks for the info - very useful. That picture is worth 1000 words .

The tires - wheel issue is huge for the current 991.2/GT4/GT3/GT3RS - I constantly see them being flogged by well set up 997 Series II GT3s running 18 inch wheels with high quality soft compound tires. You can get Trofeo Rs but these haven't moved on much in 7 years and can only be described as marginally better the MPSC2 N1 and thats in the dry.

Porsche need to step up to the plate in this regard because it has become a real limiting factor for those of us that are active in various competition where the base car requirement is that the vehicle was road registered on delivery (e.g. GT4CS/Cup Car is a non-starter - literally).

BGB Motorsports

It's IPD Plenum & BMC filter time!

arter

IPD hasnt even dynoed a 991.2 series carrera themselves.

LavaGTS

Please report back on the IPD fitment once you get a chance.

Thank you for sharing.

LavaGTS

Could have swore there was a dyno out there showing a 22hp gain under the curve.. Not to say that's the gain to be had.

From the last pic BGB posted, it looks like the IPD piece flows much better.

PTS-BRG

Oh man, I am so glad John is doing this. Time to put up or shut up to the IPD boys.

If it delivers even 15hp I will buy it. Anything less its just too minimal to bother.
Also, in conjunction with the BMC it should really show improvements in flow over stock filter.

We shall see...