Check out rotarynews.com. Yaw is building a SC Renesis motor for Speed World GT. Says the Renesis bell housing bolt pattern is same as previous 7s. So will the Renesis 6spd fit on FD? Will it handle the torque of the FD? I wanna know.

 

I was wondering the same. The gear ratios are fine. It will rev. about 10% higher (I haven't actually done the math, just a quick comparison). This would probably be fine, as many owners would like it to rev. a bit higher. It is the Miata 6 speed (according to the RX-8 Technical Highlights CD) with extra syncros (I think it said triple syncros added on two clusters). It could be dicey as a 3rd gen has almost twice the torque. I'm willing to test it if anyone wants to "lend" me one ;-). The RX-8 engine revs. way higher than ours. It just opens the extra intake port at what is our redline! Amazing work.

 

I don't understand why people question if it will handle the 7's torque and power, moreover when they say the 7 has way more power. That doesn't make any sense since in stock form they are both rated approximately the same in HP.

Definately worth the swap if your trans is thrashed but not for just a bad synchro.

 

I think I looked at this a while back and came to the conclusion that the gear ratios would not be good for the FD... I also strongly believe that this transmission would not reliably stand up to highly modded FDs... The RX-8 might have about the same HP, but the torque that it puts out is about 30% lower than the RX-7.

And let's not even get into the PPF or other issues like shifter location! It may or may not be possible to swap the gearsets into the FD box, but I kinda doubt it would work....

Brian

 

Why would you even want 6 gears?
I barely use the 5 I have.
After 4th your way past breaking the law anyway.

 

Torque is different than HP. HP is calculated from torque and RPM. High RPM doesn't really hurt a tranny, high torque does. Imagine a 300hp Powerstroke diesel that puts out 500+lbft torque. Think the FD tranny would hold up to that motor? NO, it won't. Of course you'll throw up some dyno graphs of a FD that puts out 500lb ft of torque and say see, it does hold up. Well factory reliability is different than just working for a few years in a few cars. I know a guy that has a 300hp turbo'd 1st gen that had a 1st gen trans last 3yrs. Sure it worked for a while, when he tore it apart it was pretty much all junk.

A Miata trans is similar to a 2nd gen trans IIRC.

What might be more interesting is that the RX8's motor might fit to a FD tranny!