FAQ: Automatic Transmission Swap( compiling info)

[nonamekid]

Right now this post is for moving all the automatic transmission info from the other FAQ into a different post. If anyone has swapped in a 4-speed auto tranny, feel free to tell us how it is done.

In addition to the lower final drive ratio, Aspire ATXs also had lockup torque convertors. Still 3 speed, though. No computer controls; just one vac line off the tranny, and some electrical plugs.

To those thinking about swapping in a 4 speed automatic from a 323 or other Mazda, I believe the theory is that these transaxles all have computer controls that would have to be coordinated with a new ECU.

In other words, it would be really cool to mod up a 4 speed auto Festiva, but it will probably take a lot of electrical knowledge and a 323 ATX ECU, as well as custom mounts and possibly CV shafts. Just my guess.

Right now, for eigher MTX or ATX B6 swaps, you simply use the 5 speed 323 ECU for best results. For "usable" results, your original B3 ECU will run the B6, with less power and crappier gas mileage (runs too rich).

Karl

Yes, engineers for automotive applications design transmissions as a rule of thumb for double the HP/TQ output of the stock engine for a safety/durability factor.

Yes, engineers for automotive applications design transmissions as a rule of thumb for double the HP/TQ output of the stock engine for a safety/durability factor.

actually, thats done because the torque converter, near total stall, can nearly double the input torque....