88TII 5th gear is higher than 89TII 5th gear??? I thought they were the same, with the only exception of the japanese domestic market TII trannies having a very high 5th gear.

 

[quote name='DareBee' date='Jul 27 2005, 07:40 AM']Isn't that what I said? (with exception to the B series part)


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No. There are 2 different series of transmissions in fc's that are not interchangable between them. The M series is in the 1st gens, n/a rx7, miata 5 speed and a few other. The R series, which will NOT drop into an M series case, wsa found in the fc TII and FD and others.





Cheers, the top gear is definately different between S4 and S5 TII trans.

 

interesting to note that the new miata had a new mazda designed 6 speed, not the one thats in the older miata/rx8.



speaking of the older 6 speed, ive never seen one fail, and they actually seem to shift ok once its broken in. granted our customers arent hot rodding anything though

 

[quote name='mazdaspeed7' date='Jul 27 2005, 09:56 AM']The M series is in the 1st gens, n/a rx7, miata 5 speed and a few other.
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That is exactly what I was thinking when I typed my first post; upon re-reading I realize that I accidentally typed FD where I had MEANT to type FB - sorry for the confusion. I also did NOT specify NA ONLY.



Also - someone was telling me the other day that the 79 - 80 FB had a different tranny altogether, I cannot confirm this 1 way or the other. Maybe someone else has input for this.

 

[quote name='DareBee' date='Jul 27 2005, 12:17 PM']That is exactly what I was thinking when I typed my first post; upon re-reading I realize that I accidentally typed FD where I had MEANT to type FB - sorry for the confusion. I also did NOT specify NA ONLY.



Also - someone was telling me the other day that the 79 - 80 FB had a different tranny altogether, I cannot confirm this 1 way or the other. Maybe someone else has input for this.


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Not really true. Its still the M series, but its weaker than the later ones. I believe the M series trans were strengthened for 81 and again with the S5 fc n/a. Not sure, but possibly again for the miata, because Ive heard that the miata 5 speeds are stronger than fc n/a.

 

So there are no alternatives to the TII tranny? 6 gears would be nice

 

[quote name='SidewaysFC' date='Jul 27 2005, 01:44 PM']So there are no alternatives to the TII tranny? 6 gears would be nice


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The TII trans is the strongest trans you can have without major fabrication. The next step would be a T56 or a supra trans.

 

Fitting different gearboxes is very possible - the kit car guys over here use the RWD Ford gearboxes with a host of other engines - all you need to do is find the right combination of flywheel, clutch thrust bearing etc. which is not easy but maybe someone else has done it already and done the hard part for you. You might not need a new bellhousing either, you could make up an adapter plate to sit between the engine/gearbox.



As far as whether the box will take the power, well it's torque that you need to worry about, I don't know what torque the mx-5 engines make compared to the rotary, but I can't imagine they're worlds apart. Our Nissan makes nearly the same power as the bike-engine in my car, but if you somehow could hook it up to the bike's cd sized clutch I'd doubt it'd last too long.



Mark

 

from what i have learned the miata 5-spd transmissions will have the same bell housing and will bolt up, however you still need a custom driveshaft and i'm not quite sure if the shifter location will be wrong.



a modification that people DO perform is to swap in the gears from the 5-spd into an FC transmission, since the miata tranny has shorter ratios.



a little interesting fact: the S5 reverse gear has syncromesh, the S4 does not.

 

[quote name='mazdaspeed7' date='Jul 27 2005, 01:39 PM']The TII trans is the strongest trans you can have without major fabrication. The next step would be a T56 or a supra trans.


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Viper