I am going to be selling my 981BS this month (picture for a quick plug) and currently looking at a 2017 C4S. This one has the “3.0 S Powerkit” (and Sport Package). Being newer to shopping 991.2’s I wasn’t familiar with this package and the Dealer (not Porsche) selling it wasn’t either, “different software for a little bump in power, like an aftermarket ECU flash” was the most I got. So I did the normal searching, found a lot more details about the 991.1 X51 kit, but now understand it’s so much more for the 991.2 than an ECU flash that was explained, and it wasn’t offered as a factory option for very long.



My primary question is around limitations or conflicts with doing an ECU flash if I decided to go with this particular 991.2 C4S equipped with the Powerkit. I might be newbie overthinking this, however, with it already have an OE flash to be more GTS like, is that going to limit or cause issues with doing an APR, COBB, Softronic, etc tune? Will the ECU still identify as an S and that will be program file/tune returned to be flashed, losing the benefits of the bigger turbos, etc of the Powerkit? Or will it identify as a GTS and is the program file/tune that will be returned to be flashed…taking full advantage of the Powerkit components and getting the higher results that a GTS Vs S normally would?



Since I know I will be modifying it, the last thing I want to do is invest in a spec like this and not be able to take advantage of it. If the results will just be the same as any other 991.2 C4S without the Powerkit there is no sense in having the GTS like components without GTS like results. If that's the case it would better to just move on from this one, no? Would appreciate any additional insight on this one, especially if you have/had the 991.2 Powerkit and already gone through this process. Thanks, guys!

 

991.2 with PowerKit is more than just an ECU flash. It includes the larger GTS turbos and increased brake cooling - both standard on the GTS. There's no such thing as a simple "OE flash".

If your question is whether or not you can tune a 991.2 with Powerkit, it would appear the answer is yes. Look for a thread asking if any GTS owners have modded their cars and you'll reach a larger potential pool of respondents.

DaveGee

 

I have 4s with power kit. Meaning it's like a GTS.
When I went down the Cobb path I used the GTS stage 1 and 2. And then when had a custom tune, they also started with the Cobb stage 2 for GTS.

No problems.

 

If you can find a tune for this particular application, you're not going to have the performance of a tuned S... The 991.2 powerkit has the GTS turbos. So the upgraded hardware will make the end result that of a tuned GTS. But I wonder if your problem will be the car's ECU is that of an S? Basically, you can't just slap a GTS file on an S/base ECU. Specific calibrations are necessary. For example, APR has a tune specific for a base car with a GTS turbo upgrade which is different (and double the cost) from the GTS software alone. So it seems possible that you could get a GTS tune on an S ECU, but I'm not aware of any companies currently offering that. You might reach out to @Tyler@APR to see if he can come up with a solution for you.

Edit: great to see @Ksdaoski has the Cobb solution ironed out.

 

My advise-its a great option to have! With GTS turbos and supporting mods on e85, you can pull over 600whp!

 

The X51 Power Kit is a very rare option from the factory. It was expensive, and gives you GTS turbos, additional oil cooler, additional brake cooling (unless you already have Rear Axle Steering and/or PCCB, if so, then the additional brake cooling is already installed), and finally, an ECU software calibration for the larger GTS turbos that come with the X51 Power Kit. For all intents and purposes, the engine is the GTS engine. The correct APR tune for that car would be the Stage 3 GTS tune, but you’d want to consider also add bigger intercoolers to mitigate performance robbing heat soak from the hotter, larger GTS turbos.

 

Hi Dave, thanks! I think you might have missed the center section details. The just a flash part was what the Dealership (non-Porsche) advised when I asked. After digging into I quickly found there are several components to it.

 

Nailed it! That is my core concern. Even with the Powerkit components, the ECU program/identifying file is still the key. I was not able to find an "S/4S with Powerkit" option listed or mentioned on any of the tuner sites.

 

I have the Carrera S w/X51 kit and the APR GTS tune. Your car will identify as a GTS when they read the ECU, and the tune APR will apply is GTS stage 1.

 

Is your CS a 991.1 or 991.2 ?

 

.2

 

So we have 3 different thoughts now.

1. The 991.2 C4S with factory Powerkit will still identify and be tuned as a 991.2 S/4S with APR Stage 1 (Sport/Sport+) program.

2. The 991.2 C4S with factory Powerkit will still identify as an S/4S but be tuned as a 991.2 S/4S with APR Stage 3 GTS (Sport/Sport+) program.

3. The 991.2 C4S with factory Powerkit will identify as and be tuned as a 991.2 GTS with APR Stage 1 (Sport/Sport+) program.

@Tyler@APR @Arin@APR can you please review this thread so far and advise? Thank you!

 

FWIW with APR, the ECU will be identified by the file that was assigned to the ECU by Porsche when they updated the programming from the OEM CS or OEM C4S. Because this is a special, very specific issue, APR has most likely never seen a OEM ECU/DME file version (box code) for the X51 power kit upgraded cars.

APR DOES NOT force boxcodes onto ECUs that do not belong, they will develop a file that has the ECU identification and software version.

APR also has the capability of making a OEM stock power output file for the 991.2 X51power kit if that is what you desire. It will most likely need to be a special request as not many customers typically ask for stock power output. They will need to know your particular ECU/DME software version (box code). The request would be placed with your preferred APR dealer, who will be notified when the file is complete and uploaded to the server for them to flash.

 

Kevin, not really a thought. I went to the APR dealer with your concerns about the X51 kit. He scanned my computer, and the "boxcode" came back as a GTS. He then flashed the GTS stg1 91 octane tune and it's been running fine for a month. There is only a stage 1 tune with your choice of octane for the GTS. I was charged $1499 plus tax.

 

A 991.2 Carrera S or 4S engine with either factory or authorized Porsche dealer installed X51 PowerKit, is then coded for that VIN and ECU forever in the Porsche system across the world AS having/being a GTS power plant. And it drives like a GTS.
Ask me how I know...