felixwankel88

ok, i have a 85 GSL, 12A, is the 12A tranny combatible with a 13B, if so early 13B or all 13B, second is a j spec 12At same tranny, and thrid how much hp is a stock 12A tranny good to??

sorry, abouth the stupid questions, im new to fbs


thanx in advance

Dustin

gilmore03

I believe the stock 12a tranny is capable of handling close too 300hp.

sa22crotor

Infact can anyone tell us what gearbox is interchangeable with what, i lost 5th last nite- does the box have spiggot bearings on the output shaft and how easy is the box to pull down, i got a factory service manual but pics are no good and txt is blured. Can the 13b box fit a 12a, is the bell housing interchangeable? I got a big clutch and the box has **** it's self in 1 year with no drag time! It's at 140hp now with standard everything, done the service on box to shut it up but nothing. looking for a box to take 400hp and havn't found any mazda items!

steve84GS TII

All rotary bellhousings are the same pattern.(after about 74)
You can swap any trans onto any engine from 1st to 3rd gens...................provided you select/install the correct rear balance weight and aftermarket flywheel...then mix and match the correct clutch and starter to the selected transmission/flywheel.
Its all pretty flexible,but you have to know exactly what you are doing.The consequences will be an out of balance engine,improper starter engaugment and-or clutch/trans input incompatibilty.

And for the record,torque is what kills transmissions.Torque is produced by the engine,but is applied by the clutch..........and guess what controls the clutch...you!!
Most RX-7 trannies are pretty stong,especially the TII boxes which are commonly used on some very powerful turbo 13Bs.They can take quite a bit of torque,but no trans is going to hold up to repeated clutch drops,high RPM launches,sticky tires and general abuse.Even an anemic 12A can produce enough torque to break a trans,if its applied incorrectly or in an abusive manner.