Makes sense that it is, but I figured I'd ask to make sure. Reason is I'll be using an adapter plate to mate a Miata 5-speed to a Ford Crossflow. The plate is ostensibly for an RX-8, but that transmission is a bit heavy duty for what I need. I'd rather run the Miata item, as they're more plentiful (at least around here).
Rotary engine and Miata engine have different bolt patterns plus the input shafts are of slightly different length.
Nope. Not the same.
Earlier RX-7s used the basic 5 speed found in the Miata. That trans should bolt right up.
Mazda rotary engines in the RX7 and RX8 have a different bellhousing pattern than Mazda B-engines in the NA and NB Miatae, both of which have a different bellhousing pattern than Mazda MZR-engines in the NC Miata. Even if the otherwise "same" transmission is used between some of them, different bellhousing patterns are different.
Hang on... some of us are getting this mixed up (I think).
As I am understanding it, the important factor is the Ford crossflow engine, and you have an adaptor plate which would bolt it to an RX8 trans.
That adapter plate will not bolt to a Miata trans.
AND, a Miata trans will not bolt to the crossflow.
It will bolt to an RX8 trans, OR it will bolt to an RX7 trans (FC).
The RX8 uses a PPF (which is different than the Miata's). The FC does not- it uses a transmission cross member.
That clears things up considerably. Thanks guys, I
knew you wouldn't let me screw up. SVrex, you have crystallized my thoughts!
There are also something like five different rotary bellhousing patterns, all of which are slightly different although after '74 you can generally get enough bolts to go in to work.
There are also two different input shaft diameters. RX-8 uses the same as Turbo II and FD.
Not a rotary expert here. When I said FC, I meant Turbo II.
I have a Miata, an RX8, and an FC Turbo II transmission all laying side by side in my garage.
(Yes, as noted the bell housings on the FC and the RX8 are different, but would bolt up adequately).
Interesting side note (which won't help you at all)...
The tailpiece from the FC and the RX8 are interchangeable, which means an RX8 6 spd could be installed in an application that would not permit the PPF. With an FC tailpiece, it could be supported by a crossmember.
Opens some interesting possiblilities...
Yes, it does. The Ford box I'm using now in the Pinto is the one that came with the car - the English single-rail 4-speed unit found in Cortinas, 1600 Capris. Ford's Type 9 5-speed is a popular option, but the ratios are identical (except for 5th). The Mazda RX-8 box is being used over in the UK with great results; much better ratios, cheaper, and able to handle decent levels of power. I plan to eventually upgrade to a 2.0 Zetec Black Top, and the plate will work with that as well.
The response to this thread is why I love the GRM forums; it's so supportive here. 
BTW SVrex, whats a PPF?
In reply to Pushrod:
Power plant frame.
It is a brace that ties the transmission to the differential through the transmission tunnel. The Miata and the RX8 do not have a rear cross member to support the transmission. Instead, it is tied to the differential. It's a spine.
The Miata's PPF is reasonably minimalistic. The RX8's is fairly massive.
SVreX wrote: Interesting side note (which won't help you at all)... The tailpiece from the FC and the RX8 are interchangeable, which means an RX8 6 spd could be installed in an application that would not permit the PPF. With an FC tailpiece, it could be supported by a crossmember.
Are you sure about that?
It's my understanding that the 6 speed is an Aisin-Warner unit completely unrelated to the good ol' Ribcase dating back to the mid-70s.
However, in the home market, they sold RX-8s with 4 port engines and 5 speed transmissions. I suspect that THESE are the RX-8 transmissions that can share a tailhousing with a Turbo II.
In reply to Knurled:
I'm sure I took the tailpiece off a 6 spd RX8 transmission and swapped it with the tailpiece of an FC.
Pushrod wrote: Yes, it does. The Ford box I'm using now in the Pinto is the one that came with the car - the English single-rail 4-speed unit found in Cortinas, 1600 Capris. Ford's Type 9 5-speed is a popular option, but the ratios are identical (except for 5th). The Mazda RX-8 box is being used over in the UK with great results; much better ratios, cheaper, and able to handle decent levels of power. I plan to eventually upgrade to a 2.0 Zetec Black Top, and the plate will work with that as well.
Hey, I just sold my Type E four speed. If you're just looking for new gears Talor Race Engineering have lots of parts, but cost like race car parts. The call it a Quaife Rocket and the Type 9 Quaife Sierra.
I would consider a 2.3 liters T-5 with the 2 upper bolt holes rewelded to match the bellhousing. Otherwise they are the same. Flywheels match can swap over too.
SVreX wrote: In reply to Knurled: I'm sure I took the tailpiece off a 6 spd RX8 transmission and swapped it with the tailpiece of an FC.
I don't think you have an FC trans if you did that. The FC trans is either a bottom load trans based on the old RX2/3/4 trans or M15M-D trans-both are 5 speeds. The RX-8 trans is either an Aisin trans similar to the 6 speed found in NB Miatas, or the Mazda 6 speed found also found in the NC Miata. Neither FC trans "tailpiece" will swap onto a 6 speed.
In reply to Knurled:
Actually the five speed/four port RX8 was sold in the U.K. as well.
you were able to swap the shift shafts too? I hate to bump an old thread but if this is the case I will order up my clutch kit and begin my trans swap today.
did you use the Turbo tranmsission I assume? did that move the shifter more rearward in car?
You'll need to log in to post.
