So i recently did a n/a to turbo II swap on my 1991 rx7. thats both the engine and transmission(auto to 5 speed). i had a few questions.

1) is an ECU swap necessary?
2)is the open to lsd rear really necessary?

how hard are these swaps and any other recommendations?

This is my daily driver/show car.its not a drift car so i personally see no need for lsd but idk.

 

you need to use the rear end from the Tii if you're using the Tii tranny as the Tii tranny is a couple inches longer, making the driveshaft a couple inches shorter. the NA driveshaft will be too long and wont fit. so you might as well do the whole thing, unless you'd rather go get a custom driveshaft made.

 

1. Yes, the ECU swap is necessary because the NA ECU doesnt know how to deal with boost and all that goes with it. It will run with the NA ECU, but once you give it some boost it will end; badly and quickly. Note that the N374 JDM ecu probably won't work so you'll need the N370 one.
   
2. No, the LSD is not needed but you'll need to modify the driveshaft or get one of the special Mazdatrix ones. When we did our conversion we bought a modified driveshaft from - ironically - a drifter. It's worked well. It appears he had the bolt holes on the Tii driveshaft elongated to fit the pattern on the non-LSD diff. We have an S4 LSD and axles ready to go in but just not the time to put it in. Car works great.

There are good articles in the FC archives above and you'll find good swap info at www.rotaryresurrection.com

 

the lsd is not nessesarry i still have my open diff and daily drive it and i drove it hard with no problems at all just get the mazda trix drive shaft so you can use the turbo tranny and the na rear end just dont do hard launches, all you need is the n370 pressure sensor, n370 mass air flow meter, n370 ecu, if you use the n374 it will not work with out modiftication to the inside of the ecu and get a turbo throttle cable, its an easy swap, and you can use the na wiring

 

There's someone here selling a T2 to n/a rear end driveshaft, i got mine for only 150

 

oh the engine is in the car, it has a brand new driveshaft in it. it is my daily driver and i have the n370 in it. the ecu,engine and tranny were all bought together and the driveshaft is a custom aluminum driveshaft. will she be ok?

 

the drive shft will be fine as long as it is ment for the turbo tranny and na rear end, you will also need an n370 pressure sensor and n370 mass air flo meter and the turbo thrttle cable uless you alredy ave them

 

oh and i herd the aluminm drive shafts are alot stronger

 

If this who I think it is(guy I met saturday in H.creek) if you have the N370 ECU in the car that is fine. since it already has a N370 map as well. If you arnt really beating on it that 7" rear is ok, my only question is if it is a 3.9 ratio rear.

 

Yeah it is after u noticed that rear end i started digging it to everything else, i did find the ECU and it is an N370 and the car no longer has the stock wiring harness either, it has been changed to the turbo II the only thing not TII is the rear end. Will the turbo II to N/A driveshaft still work if i ever change the rear end to a TII or will i have to get another driveshaft? thanks

 

If you change the rear end to the 8" TII LSD, you will need a TII driveshaft. The bolt pattern on the differential flange & the yoke that connects to the transmission output shaft are different between NA and TII.

TII to NA custom driveshafts will have the TII yoke, but have the NA flange instead. Someone mentioned length being different, but they're the exact same length. It's just the bolt pattern and yoke that differ.

 

i think it is only on the s4 that the DS lengths are different