fahren

Pretty noobish to the rotary world but i've been building subies for a while.

I have an 05 forester, ej25 block, 5mt.

I've been doing a lot of research on converting it to RWD in stock trim. it involves a bit of modding to the trans, welding the center diff yada yada. and of course building the rear end to hold 100% of the power.

that said. I'd much rather find a RWD transmission that will semi easily bolt up to my ej25, with an adapter plate I hope it would be a pretty easy swap.

So any info on FC, FD, trans. reliability, what to look for, which years would be appreciated.

also if anyone has pictures of any trans out of the car I'd love to see some to get an idea of what i would be working with if i picked up an FC tranny to play with.

Dimensions/bolt patters would also be great.

I've searched a little and haven't found anything. if anyone has links to all this basic info that would be greatly appreciated.

sorry for the winded thread. salutations from the subaru community.

arghx

iTrader: (3)

I don't have any pics, but I will say that there are two families of Rx-7 transmission.

The nonturbo ones are all pretty similar from 79-91 . They are like a Miata's. They can't hold that much power... I would trust them up to low 200's and that's only if you don't do a ton of drag launches.

The Turbo transmissions are the "R" type transmissions. The FC tranny and FD are pretty similar, but there are some variations. There are a few slight differences in the gear ratios (check the specs sheets sticky), with the 87-88 being having the shortest gears of all the 87-95 transmissions. The 93-95 FD trannies have the tallest 5th and the highest top speed (this is with the factory 4.10 final drive that are on all 87-95 manual turbo cars).

The main visual differences between the turbo and nonturbo transmission, to me at least, is the ribbed/flat inspection plate on the bottom of the turbo transmission. The nonturbo doesn't have that. The turbo tranny also has two fill plugs.

The "R" type turbo transmissions are in the same family as Ford Ranger transmissions. I recently got mine rebuilt and they used a bearing and synchro kit for a Ranger, but there were a couple parts they had to get from the dealer. The most common problems on the turbo transmissions are grinding in 5th (5th is very common on FD transmissions), 2nd, and 3rd--probably in that order of how common it is. Some also have a whining sound from the input shaft bearing, and occasionally the return spring for the shifter will break.

As for power, I would say the R type transmissions are good for about 350 lb/ft (at the wheels, so anywhere from 400-450 at the flywheel) of torque reliably. After that you start breaking stuff, at least if you drag race. On a rotary that means the tranny will handle anything you can throw at it up to about 450-500rwhp, and often more than that if you don't beat on it.

fahren

awesome thanks for the info.

with my setup, i'm putting out about 310Awhp, i'm guessing putting all the power to the rear will bump that about 15whp?

so i need to look for a turbo R tranny i'm guessing.
I found a complete drivetrain at pick apart in an FC, i might just pull that and see what i can come up with. run it till it blows up then find something better to work with.

SDrotary-FC

310awd and your having tranny problems? ( i got a 06 forester xt 5mt) or do you just want the 15hp (maybe??)

it seems like a lot of work to me (for not that much of a upgrade) but ya youll need a turboII tranny at least.(and then get it rebuilt)

arghx

iTrader: (3)

don't even bother with the N/A tranny. If you don't see a flat, ribbed inspection plate on the bottom, don't even waste your time.

and that should handle your power level no problem. My car made 386rwhp 297 rwtq. If you are concerned about the durability, PM J-rat. He has a 10 second FC with 497rwhp and I think close to 400wtq. It is my understanding that he is at the point where he breaks trannies, but that's from a lot of drag racing. oh and FWIW, I got my tranny rebuilt for $700 parts and labor at a local place. They told me it's just like building a Ranger tranny and had no problem with it.