We received this Porsche 996TT from one of our Used Car customers who wanted to step up the power for the new owner. The goal for this vehicle was to maximize the stock turbos and gain as much reliable horsepower we could out of them. First, we dynoed the car stock on our Mustang AWD Dyno. This gives us a baseline to work from so we know where are mods are improving on the car. What we look for is the delta to ensure the customer is getting what they want out of the mods. Our baseline dyno test was at 364awhp and 375ft/lbs of torque. Because of the change in our dyno settings, this is a baseline of about 30hp more then normal.
Our first step was to flash the car with the VRTuned software. The ECU flash was done via the OBDII port and took about 1 hour to complete from start to finish. Upon completion, we reran the car which it picked up good power, but the stock plugs could not handle the change. With 30,000 miles on the stock plugs, it was time to change them out. We added the Denso IK22 1 step colder plug to smooth out the power. This plugs spark will prevent the car from breaking up with the increased boost. This change required the exhaust to be removed. So at this point we added the Agency Power Exhaust System. The total install on this was about 5 hours.
Since the flash will alter the fuel and timing as well as raise the boost from about .7bar to 1.0bar, it is necessary to upgrade the stock Bosch diverter valves to a strong spring and piston design like the Agency Power units. These valves do not leak boost at the higher rpms like the stock units. To change these out takes about 1 hour. Now with the basics in place, to allow the turbos to breathe better, we added the Agency Power Carbon Fiber Dual Flow Intake kit. This kit replaces the stock air filter with a K&N unit as well as adds the addition of a second snorkel for increased air flow. The more air that is present, the better the turbos will perform. To swap intakes is about 1 hour.
Finally, because this car will be used for both street and track, we added the Greddy Profec B boost controller. The boost controller allows you to set both a high and low boost. This way if the customer wants to run 1.0bar on pump gas and 1.3bar on race gas, we can easily make the switch. Since VRTuned tunes off the factory knock and O2 sensors, there is no need for a race map as the ECU will adjust to the octane. The boost controller also has a warning feature that if boost hits a preset limit, it will cut back by a % to save your engine… how nice 🙂 Since you have to run lines through the interior into the engine compartment, a good installation is about 4 hours.
In the end, the car achieved a 100 horsepower gain which is on par with these modifications. This is a good basic review of how to start off a bone stock Porsche 996TT and achieve good performance results. Total installation time is about 12 hours. With these mods, a base has been set for a modular upgrade to say the K24/18G turbos.
Enjoy!
