For us who currently or who had a FD, We all know that we miss shift going from 2nd to 3rd will destroy your 5th gear synchro like how old mustangs were. Im wondering two things at this point:

1.) Did Mazda redesigned the RX8 Tranny to be able to take a little abuse? And redesigned the tranny where speed shifting from 2nd to 3rd the gate won't slide and make you mis-shift.

2.) If you would be able to bolt on the RX8 tranny to the FD?

My 5th gear synchro is completely dead, i have to rev match + doulble clutching to get in 5th without grinding right now. If the Rx8's tranny's 6 spd can bolt on, it would be better than rebuild my existing tranny.

 

Bluesaint,
Back in the day (as in about 2+ years ago) I had heard things about how the then new 6 speed tranny in the Miata was tested and shown to be able to handle WAY higher loads than the Miata would ever be able to place on it. Many speculated that the basic construction of the Miata 6 speed would be found in any new RX cars. This was even before the RX-EVOLV, when there were rumors about a more traditional sports sedan with a rotary.

I'm sure they'll change the gearing to best fit the RX, but it wouldn't surprise me to see that the architecture of the two trannies being very similar. Just seems a little silly to make a 6 speed for the Miata only.

So, I've never heard of any problems about 5th synchros going on any Miata, or on any other Mazda for that matter. But being that the RX will be 6 speed guaranteed would lead me to believe the RX-8 tranny will have NOTHING in common with the FD tranny.

 

The Miata's 6-speed box is the same unit used in the Toyota Altezza RS200 (I think that's the name) which puts out 210hp from a BEAMS 3S-GE. So yes it can handle alot more power than 142hp.

 

well, im sure the gear sets inside the tranny housing might be pretty similar to that of a miata 6spd, but the mounting points that hookups to the rx8 would be probably more similar to that of rx7 then miata, so there is hope still. But can't really tell until they come out.

 

KrisA
How do you know that? My understanding is that the Miata 6 speed is a Mazda tranny, and shares nothing with Toyota's. Or is this some project car that uses a Toyota chassis, with some other engine, and a Mazda tranny?

 

I've heard that numerous times from a number of sources. The tranny is made by a 3rd party company in Japan, neither Toyota or Mazda own the design.

The Altezza is the Japanese version of the Lexus IS. Only difference is that over there they offer it with a hot 4 cylinder (the 3S-GE one of the greatest 4 cylinder engines of all time). If Toyota sold the RS200 in North America I'd forget about the RX-8, trade my Mazda Protege in on one and live happily ever after.

 

yea... Aisin makes the tranny's for mazda