Here's the type of exhaust you'll need to get very high performance. This 3.8-liter 993TT by Protomotive does 60 to 130 in under 6 seconds using 91 octane @ 1.1 bar.

 

WOW, can you post other stats/pics of the car?

 

Not easily. Given the amount of engineering invested by Protomotive, it's best to contact Protomotive directly for stats and pricing. They make very fast cars.

 

protomotive i believe endorses japanese styling tuning please correct me if i am wrong that is one bad *** open to atmosphere external wastegate setup..

 

Too bad this was moved to the 993 TT forum. The exact same setup applies to the 996 TT.

 

That is a bomb *** external wastegate setup!!

That's really interesting, I never knew that... Thanks for the info Bill S.

 

Wow! nice setup!

Todd Knighton was building sick fast cars well before the Japanese started building HKS wastegates. While his engineering and component matching skills are amazing, his even bigger stength comes in Motronic tuning. Try finding a tuner who can make a twin plug, pressure sensing (no MAF!!) Porsche engine be controlled with Motronic.
Intensive testing on an engine dyno is how to achieve real performance, and the ONLY way to do it.

 

now thats a good serious motor.
I'm used to RX-7s and that sorta stuff is typical. Seems that you porsche guys just seem to make such great power from stock equipment w/ exhaust and hybrid turbos that you dont really delve into the darkside too often.
Very **** looking motor.

One thing I don't see, is why no straight pipes right from the turbo to exhaust tip, like a 1' passage, and no big exhausts? you have that in a 3" and you have NO backpressure with dual turbos.
turbos create all the backpressure you need and by then youll already be in boost.
I think fabspeeds 996 muffler deletes or ive seen em called "gt2 pipes" are what im thinking of. Maybe it was something else
But it had a hiflow cat bolted directly to turbo, and then just a short straight pipe out the back. straight shot.
I wonder how the cat would effect the spooling of the turbo and the cat also add more than neccesary heat to the turbo? Guess thats a good reason to keep the stock cat position.

Maybe just bolt a straight through muffler to the turbo instead and weld a tip on the end

Ooooh, just thought of one other problem with that, no heater. damn aircooled motors!

OK, I'm done blabbering.
-Ben Martin

 

That's the kinda plumbing I have on my twin turbo Viper. It's explosive to say the least. This Promotive style is very interesting and unconventional yet innovative for the Porsche world.

 

The car has one single muffler in the center rear section that has been modified (you can see little holes inside of it in the picture). I don't have cats because I don't need them in this country (as well as heater). The reason it does not have straight pipes is only for sound reasons, but the backpressure is minimal with this setup, other than the slightly smaller turbines that were used in the Garretts since it is a street car. The exhaust pipes are 3 1/2" , I have welded (closed) one of the sides to reduce the sound levels.