well i sold my rx7 a while back and now i miss the rotary, i have a 1989 mazda pickup b2200 and i blew the motor 2 months ago. anyways my friend has a 12a carburated motor sitting in his shop wich he said i could have he doesnt have the tranny though. i was wondering if my trucks tranny would bolt right on and if so wich kinda clutch would i have to get to make it work. if it doesnt bolt on i could get a rx7 tranny for cheap, how would i make the driveshaft work. one more thing is the there any wiring i have to do or computer changes? anyways thanks any extra info would also help

 

go to WWW.MAZDATRUCKIN.COM and look in the Rotary powered section there will be most of your answers.. if you dont see what you are looking for please post up as I am on there @ least 2-3 times a day...

Later
Dan Atkins

 

I don't know how much your B2200 weighs, or which gearset the rear end comes with, but you might want to consider a ported 4-port 13B instead. The REPUs weigh around 2730, came with a 13B 4-port and the manuals had something like 4.67 gears in the rear end, autos had around a 4.30 gearset.

With a stock port 12A and rear gears meant to work with a pistons torque curve and rpm range, you may find the 12A a bit weak performance wise. The 12A has 101 base hp and 105 lb/ft of torque. With the usual exhaust and carb mods, you can pull 140-150 hp, not sure on the torque numbers. How does that compare to the engine that came in your truck?

 

well is about 87hp from what iv read lol foreal, and the 12a is street ported and carb work and is gonna have an exhaust

 

I say do it. What do you have to lose other than a vast lump of cash? If you have the money, go for it.

 

87 hp, wow, I bet those hamsters are cheap to feed and operating costs are nil. If you are running 2wd, then use the 1st gen tranny and have a custom driveshaft made. Wiring should be relatively simple, not much needed for the carbed version, definitely no need for the Mazda ecu, other than operating the automatic choke, which can be worked around. Ecus in the 12As is mostly for emissions, not engine management.

Downlowd the FSMs and the factory wiring diagrams, that should get you up and running. If you don't know where to find them, the link is in my sig. Have fun with your project.

 

The 1st Gen RX7 gearing in the tranny is the same as the B2200/B2000 except 5th gear which is .858 in the truck and .825 in the 7 I think. If you take the bell housing for the 12A and put it on the truck transmission, then take the 7 5th gear and swap it also that will give you a 5th gear ratio of .835 and you won't have to spend the money on the driveshaft unless you want to swap the rear end.

The truck differential is 3.909, might be 3.7xx for the automatic if I remember right.

If you look in the B2200 tech section I have info on modifying the transmission. The tranny selection page disappeared somewhere though. I'll have to write another one.