not sure of your question, but are you asking if you can run an atc pipe on a trx? yes you can, but you need to build another mount
i have never compared the atc pipe and trx pipe, yet i have had both. I dont think you are going to notice much difference in power between the 2. You are correct about the ATC pipe, it comes out and immediatly makes a 90 deg downward turn, and then out to the left. By rights, the trx should make more power because of the less bends and longer and straighter cones, but who really knows! Next time i have another ATC pipe ill test them on the dyno!