i was just wondering how difficult it will be to put an rx8 6 speed manual tranny, differential, and axleshafts in my 91 rx7. will it bolt in fairly simply? can i use the stock hubs? would i need a custom driveshaft? has anyone even done this yet?

the trans bolts to the engine and will work with a turbo 2 clutch. the trans mount needs to be custom, as the rx8 has a power plant frame. rx8 drive shaft is probably longer, cause the car is longer, and its carbon fibre so you cant cut it. the center section of the rx8 rear end may bolt into the turbo 2 aluminum diff carrier thingee, if it doesnt the mounts are totally different, and would have to be made. axles may or may not work, t2 ones would be a better choice.



rx8 diff is basically an the same as the turbo 2 diff with a short pinion, and since the turbo 2 diff bolts in the car, it would be easier to just use that.

Not going to happen the FE is much wider then the FC and longer. You have allot of sensors on the tranny that won't work but with some work you can work around it.



I heard something about the Eshafts but frankly I just do not remember but there are differences.



As well the gearing makes this worthless.

what about 3rd gen 6 speed with t2 diff and axleshafts? id really like a 6 speed, but if that wont work, ill just use a t2 5 speed.

You are still bataling the digital speed sensor and N switch as well dont mount the same. So you can do that with some fabing and posibly adapters for the speed sensor.

but the trans should still bolt up to my engine, right? im willing to do a little fabrication if i need to, since i wasnt really expecting it all to be that simple. and where can i get the adapters for the speed sensor? would it really be worth all the work just to have a 6 speed? if i need it, a friend of mine has a t2 tranny i can use if i cant get the 6 speed to work.

here is a qoute from a another forum





Can I install the RX-8 6 speed transmission into my 2nd Gen RX-7?

5th gear on the FE tranny is the same as the 4th on FC trannys anyway, so there is no real advantage of using the RX-8 tranny, and 6th on the FE tranny is actually taller (.83 vs .71) than the FC, resulting in lower gas mileage at highway speeds.

Using a RX-8 tranny would be like adding a extra gear between 2nd and 3rd to a standard 2nd gen RX-7 M or R type transmission.

alright, i think ill just go with the t2 drivetrain. thanks anyways.

The gearing of the RX-8 (it's SE3P, not FExx - check around to see for yourself) would still be worth having if the rear-end gears were being made taller (lower final drive number). And there is certainly something to be said for having a "new" transmission, all nice and notchy. Even if the rotor-shaped shift-knob is a bit goofy and uncomfortable to hold.

well, shift-knobs can be switched, but changing the final drive may be a problem unless u are willing to fab in mounts for either the 8's diff, or one from a different car. IIRC, all of the "bolt in" rear diffs for the FC are very close in ratio, they have a listing of it on mazdatrix's website