Beyond the 944 work I do around the shop, my favorite cars to work on and upgrade are the 996TT and 997TT’s. There is something about being able to take a fairly new, well engineered vehicle and make it even better. Our Stage IV kit for the 996TT and the Stage III kit for the 997TT are some of my favorites. The Stage IV 996TT kit (which will produce right at about 605hp) consists of an ECU Flash, Bigger turbos, Headers, mufflers, and high flow cats, as well as billet diverter valves and an intake. The Stage III 997TT kit (producing roughly 600hp) consists of a ECU flash, headers, mufflers, and high flow cats, and an intake. The key to both kits is that they are downright mean, without compromising any reliability issues, which is the key to any good tuning package.
Some of the components in detail, as well as other items which are added on a regular basis to make the TT’s a better all around machine.
ECU flash: About a half hour with the laptop, and we will remap the air and fuel curves in the ECU for more flow. With 50-75hp gains on the 997 and 996TT’s, this is the easiest way to get hp and tq out of the car.
Intake: The more air you can suck into the engine, the more potential for horsepower. The high flow air intake system is a must when looking for horsepower. The 996TT intake utilizes a venturi system with a large conical airfilter to allow the engine to breath easier. The 997TT intake utilizes a dual cone filter setup that will suck so hard, you will hear it when you mash the throttle.
Exhaust: If you are sucking more air into the engine, you need it to be able to exit just as quickly, so a fully stainless steel Fabspeed generation 3 muffler with high flow catalytic converters is the answer. Fabspeed has designed a new dual can system which eliminates any resonance from the exhaust, and is deep and throaty, but not overbearing. This is how the car should have come from the factory.
Imagine Auto Headers: The collectors and ports on the stock headers leave much to be desired from Porsche. Our solution was to re-engineer the bores and create triangular merge collectors with a new set of headers, to provide smoother and a higher quantity of flow from the engine to the turbos. Lower Exhaust Gas Temperatures (EGT’s) mean more hp.
Modified Turbos: The heart of the 996TT Stage IV. I’ll put this is layman’s terms: The K24’s are built to rip. Period. At 1.1-1.2 bar, they hit hard and fast, and the vertigo will start to set in. It is a feeling that is hard to explain without being able to experience it. When you mash the throttle in 3rd or 4th gear, all you can think about is keeping it between the ditches.
Billet Diverter Valves: The stock diverter valves are based off a plastic housing with a thin rubber diaphragm. This is a good design….for a turbo beetle. Once you start increasing the boost, the rubber will tear, creating a boost leak. Our solution was something that couldn’t leak. With a fully aluminum housing, and a machined aluminum diaphragm, they can not fail like the stock units, and will take all the boost you can throw at them.
Short Shifter: I know what you are thinking. You bought a $100k+ SPORTS CAR and the shifter has a longer throw than an 18 speed Peterbuilt. Shorten that throw up with a short shifter, and make the car feel like a sports car should. One of the first modifications I recommend. Don’t believe me?…..try it and you will see what I mean.
Clubsport Intercoolers: The stock intercoolers leave ALOT to be desired. With a very poorly designed plastic endcap system and a flimsy core system, it isn’t any surprise that they are restrictive. What this means, is that as the temperatures heat up, your hp decreases, because the intercoolers are not able to cool the air going to the turbos. This is why your car feels great on the first run on a 90 degree day, but the subsequent runs feel more sluggish. The solution are larger aluminum intercoolers with a bigger end cap design. The clubsport intercooler cores are 33% larger than the GT2 intercoolers, and will flow up to 50% better. This means more cooling, and being able to maintain that horsepower during the heat of the summer.
Silicone Boost Hose Kits: Another weak design from Porsche was their boost hoses. Not only do they pop off easily with increased boost, but the F hose at the diverter valves is thin and will rip. Just imagine you are going around the track, and all of a sudden you hear a big POP, see some black smoke, and the car doesn’t want to go anywhere. You’re trying to get off the track, cursing the guy that just changed your oil and bled your brakes before the event, but once you get off the track you realize that you’ve blown a hose. The silicone hose kit will keep that from happening with thicker hoses, and a better clamping system at the intercoolers.
Suspension: It is hard to beat a Bilstein PSS9 or JIC Cross suspension. From the factory, the 996 and 997TT’s sit like a 4wd pickup. Drop it about 1-1.5″ and it starts to look like a sports car. More of a street driver than the track? The Bilstein setup is the way to go. While still being 9 way adjustable, you can set it nice and soft around town, and stiffen it up for that occasional DE event. With the quick turn of a knob, your suspension is set and ready to go. If your car is mostly a track car, then the JIC adjustable suspension is better suited, and will allow you to drop the ride height as low as you need for aerodynamics and handling. Moton Club Sport suspension? Now we know you are serious.
Is there more? Oh, I could go on and on with products that we install, but these are some of the more common upgrades that we bolt on every day. Sure there are body kits, wheels, roll bars, seats, etc, but that is information for another day……