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

Mike@GTM

In the grand scheme of things, it would be ideal to do both the Twin Turbo and Transmission at the same time. Ultimately, it would save on transport costs and doing it all in one shot would allow you to truly enjoy the car from the get go.

In regards to the second half of your question, I personally feel like it's a really tough pill to swallow doing the transmission first and then doing the TT later as the performance gains from just a transmission build aren't exciting enough on their own to justify the cost. If it were me, I'd do the Twin Turbo, transmission cooler and tune to increase line pressure first, drive the car and enjoy it (within reason) while saving up for the transmission build.

Again, it's not truly necessary to build the transmission to have fun and enjoy the car. For example, I know that the transmission in my Subaru is made of glass and is ultimately a ticking time bomb...that didn't stop me from upgrading my turbo within reason and enjoying my car for what it is. I just take care of it and don't beat it like a drum...simple as that. I still track it occasionally and stomp on the go pedal when I feel like it, I just don't abuse it and change the fluid regularly. One other tidbit is that I do not take it to the drag strip because I know that all it takes is one bad launch to grenade that box into a trail of shrapnel. Know the limitations of your hardware and drive accordingly.

The bottom line is that if you are adamant about doubling your power and want to thrash the ever living $#!^ out of your car, then yeah, you ought to build the transmission to take the abuse.