sideways_swe1

I own a 997 GT2. I bought the car this spring and previous owner had used it very carefully. My guess is the clutch is as good as new and it feels that way. Anyway,

I am getting exhaust with 100cell cats and a protomotive tune. Can a stock clutch handle the power upgrade? I mostly use my car on the road but i do some track from time to time. Never launches the car.

I also have another question regarding exhaust. The stock exhaust is as you all now titanium and made by Akrapovic. I am thinking about just to swap the stock cats out for 100cells. Is that to recommend? Will i "lose" power compared to a more freeflowing louder exhaust? All answers is much appretiated! Thank you

mepps

doubt it will be any louder just doing the cats.

sideways_swe1

Im not doing it for the sound. I kind of like my gt2 being a little quite compared to the gt3 with cargraphic race kit. Im wondering if i will "loose" power with stock exhaust with 100cell cats compared to a complete crosspipe exhaust for example. I know a more freeflowing exhaust is better when tuning more heavily. But with a tune only?

Protocav

The best exhaust for a turbo is no exhaust. If this was an NA car, it would be different, but the turbo should love the reduced back pressure.

M3EvoBR

You will most likely need to replace the clutch.
The 100 cell cat will make the car a little louder and yes you also could benefit from a larger diameter for increased power and torque.
Most important thing is the air intake temps on those cars that are pretty high, so invest in some good intercoolers if you want to have constant power, as anything over 50C the DME will start retarding timing therefore loosing power. Also pretty easy to hit those temps with stock intercooler and tune with increased boost.
No reason to use a crossflow exhaust, just to create turbulence ?
Like Protocav said in turbo bigger the better, but in our cases we are restricted by the small hot side turbo which already generates decent amount of back pressure. Any 3'' or 3.5'' should do the trick.

bhgt2

I can say with some confidence that your clutch will go very very quickly. My car was lightly driven, never tracked, low miles, and the clutch went immediately after the tune.

I know guys who have installed cat-bypass on stock exhaust and are very happy with the result.

TB993tt

My stock clutch slipped when car was in stock tune when the temperature went below about 15C as the engine makes a nice fat 700+NM, pal's 997GT2RS did exactly the same so a tune which increases torque will definitely fry your stock clutch.

The 100 cell cats with stock exhaust makes more noise but it is a nice noise. I have a set of 200 cell bolt on Cargraphic cats (done ~3000 miles) if you wanted a deal.

sideways_swe1

Thank you so much guya for all the info! It looks like i am replacing the clutch to. Its better to have a spare stock clutch if next owner wants the car stock. Do you guys have any suggestions on what clutch to use with "stage 1"? I dont think i will go any further rhan tune and exhaust. I want the clutch to work as a stock clutch because i drive the car in traffic. TB993, i'll send you a PM soon about the cats, thanks!

M3EvoBR

If not going any further, the stock GT2RS clutch will do the job.

bhgt2

I'd recommend a Sachs 2.5

TB993tt

Is the GT2RS clutch not the same as GT2, it has the LWFW but I thought the clutch was the same, as I said my pals RS slipped when it was standard and brand new and the RS has virtually same torque as GT2, 700NM vs 690NM - it is the torque which slips the clutch.....

My car and the GT2RS referred to above both have the 890NM Sachs set up which (on my car at least) is indisiguishable from stock..

M3EvoBR

The RS has a different clutch, the GT2 has the same clutch as a TT car. THE RS has the LWFW correct.
Always the torque that causes the problem. My car slips the clutch if I'm not very gentle with the throttle and I'm still on stock exhaust and very mild tune.

sideways_swe1

Does the gt2 really has the same clutch as the turbo? Ive owned a turbo before and that clutch felt way different. Gt2 clutch is much heavier. (Not sure how otherwise to describe it in english )

Maybe previous owner already changed my clutch? It is heavy and rattles. Does a stock gt2 do that?

TB993tt

I thought the GT2 has a different disc - is this not what the PET shows below (I101 being GT2) ?



Which clutch bits are different (from the GT2) on the RS - I was pretty convinced they were the same particularly after my mates stock one slipped, I told him "they all do that"

M3EvoBR

The master cylinder and actuator system is completely different between turbo and GT2, that's why they feel different, the parts actual disc pressure plate are the same.