Theirs not point in having one. The 6th gear of the FE tranny is dam near the same as the 5th gear on s5 turbo trannies so you only shift more (6th is NOT an overdrive gear). Torque breaks trannies, rx8 has 164ft.lbs which is less than a stock kouki turbo. Basically they took an fd tranny, made it smaller, shoved an extra gear in there (which means the gears are smaller-made to fit) and gave it crap for torque/horsepower hoping nobody mods their car and break it. I know a guy fron rx7club running 487rwhp to his stock s4TII transmission and it still holds up fine after 50,000miles of mild abuse. But you can use a 6spd T-56 tranny from any chevy which can bolt up with the right Kennedy Engineering bellhousing adaptor.