GTM Performance Engineering: GTM TD05 16G Test Results 91 Octane 7AT

Mike@GTM

It's not a question of boost pressure, it's a question of cylinder pressure. Average cylinder pressure is measured by torque at the wheels. The other factor is load. You can make a serious amount of torque and be perfectly fine. When you do a 6th gear pull with tons of torque, however, you are putting way more load on the connecting rods than a 3rd gear pull with the same amount of torque. Therefore, it's really important to be clear about what you are doing with the car when trying to determine what level is "safe" for you.

Yes, the car has a boost controller on it.

Generally, we don't recommend high flow cats on forced induction applications because they really just don't last long enough. It's either OEM cats or test pipes. The only time you see us do any kind of testing with HFC's is if the customer already has them and insists on running them.

We use a bell mouth design on our downpipes and O2 sensor housings. In our experience, the bell mouth design works exceptionally well.

On the twin cooler setup, the charge air flows from the bottom to the top. As a result, the crash bar doesn't really affect the coolingh. The big single cooler on our Garrett kit flows side to side, however, and the crash bar would block airflow to the upper circuit.

No issues so far with boost control. Keep in mind, however, that the 16G setup is geared towards people with factory or mildly upgraded exhaust. Think of it as a OE style twin turbo conversion.

That all said, these turbos have a really nice, smooth, rounded transition from the turbine scroll to the wastegate flapper. This allows exhaust gasses to make the tight turn towards the wastegate more easily and ultimately improves boost control.