Fitting a 5MT from 97 impreza to a 98 Legacy wagon AT

[ashino]

Hi
I was thinking what electronic problems i might run into when i change my AT in my legacy for a 5 MT from a impreza i have in my garage.

Will i need just to change the cars ECU or will i have some more problems with hanging wires from the AT?

and will i have to change the rear diff?

all comments are appreciated.

regards: bragi

[jey]

You will need to change the rear diff if the final drive of the transmission is changing - front and back need to match.

[ashino]

You will need to change the rear diff if the final drive of the transmission is changing - front and back need to match.

so i need a rear diff from a legacy/impreza/forester with the same sort of transmission?
What about electrical problems, in the engine and throttle, from the setup of having a AT, and the electrical system that turns the car from FWD to 4WD?

[hallowpoint]

^^our cars are AWD not 4wd. there isnt an electrical system for the center diff(only in new cars) but yes you will have to match the gear ratio of your tranny to the rear diff. what is the ratio of it? what car did you get it out of?

[ashino]

^^our cars are AWD not 4wd. there isnt an electrical system for the center diff(only in new cars) but yes you will have to match the gear ratio of your tranny to the rear diff. what is the ratio of it? what car did you get it out of?

The legacy has some sort of electronic system which allows the car to be 90% Front and 10% Rear drive, at least in 3d and 4th gear, there is some button or something in the engine bay, which allows the car to be only FWD for towing or something. i also notice that the front wheels spin first on take of exept when i am in the "locked" 1st or 2nd gear.

The transmission is from a 1997 2.0 subaru impreza. I am planing on taking the front axles out and make the car RWD for the summer and then change it back to AWD in the winter, because i live in iceland. So the only thing i will need is a new clutch and rear diff? ( i have the whole clutch pedal and stuff from my impreza) I am mostly worried about the compuiter and electronics, that is something i cannot work out for myself.

Might it be possible to put in a rear diff with LSD? perhaps from the legacy 2.2 gx around 1991?

[jey]

On a manual transmission you can't just take out the front axles and the differential will suddenly divert power to the rear. That is not the way to do a RWD conversion.

[ashino]

How do I convert the car to rear wheel drive?

And is it possible to revert that?

otherwise i will just stick to the auto to manual swap.

i do not have my answer for the electronic part of the swap, if there will be electronic management problems or something.

[mike-tracy]

Your electrical q's:
http://www.rs25.com/forums/f128/t93945- ... ssues.html (http://www.rs25.com/forums/f128/t93945-automatic-trans-manual-swap-wiring-issues.html)

Not too many people swap their subies to rwd. Not sure why.

[jey]

How do I convert the car to rear wheel drive?

And is it possible to revert that?

Weld the center diff. Similar to what people do with their rear diffs to make it fully locked. Very difficult to reverse obviously...

[ouch1011]

You would have to plug the outputs from the tranny for the front axles as well.

Why would you convert to RWD? That would be pointless.

[prodriver1]

if i didnt live in the icy depths of the tundra i would totally convert to rwd.

[Huffer]

You would have to plug the outputs from the tranny for the front axles as well.

Why would you convert to RWD? That would be pointless.

Because it's different, why else do people do things to their cars? Because sometimes it's fun to do...

Has everyone forgotten mranlet's drift outback? Or Sybir's long gone DRFTSUB?

Shoot what about the CUSCO D1GP drift STi??

Cusco MAKE a center diff that directs up to 70% to the rear...

[ouch1011]

I knew someone would say that. :)

Sorry, I just think that converting an AWD car to RWD is ridiculous. Its a considerable downgrade in almost any respect unless your goal is to lose traction and drive slower (i.e. drifting). I can appriciate being different, that's why I bought this car (well, part of it) but come on...

[ashino]

^^our cars are AWD not 4wd. there isnt an electrical system for the center diff(only in new cars) but yes you will have to match the gear ratio of your tranny to the rear diff. what is the ratio of it? what car did you get it out of?

If I would weld up the center diff. to make the car RWD, could i not weld up the rear diff from the auto car and use that since i would have no drive in the front wheels?

What would happen if i were to use the automatic higher ratio rear differential with the lower ratio transmission, with or without a welded up center differential?

i would really like to make this car RWD preferably with a lsd, but otherwise have one diff welded, and have an open diff for replacement.

Can anyone find a list of gear ratios for me? and btw i live in the arctic tundra that is iceland, but i still want to have my car RWD. We have real trucks here to deal with the snow.

*EDIT
my gear ratios on the AT are: 1st 2.785 2nd 1.545 3rd 1.000 4th 0.697 Rev 2.272
and on my MT the ratios are: 1st 3.785 2nd 1.945 3rd 1.500 4th 0.994 5th 0.780 - Final 4.11

[DarkPhoenix]

Okay, what you need to find is the final drive ratio of the rear gear and see if it matches what you have in the impreza transmission.

Oh, and turn your volcano off. It is screwing up my international shipping.

:-)

[jey]

If I would weld up the center diff. to make the car RWD, could i not weld up the rear diff from the auto car and use that since i would have no drive in the front wheels?

What would happen if i were to use the automatic higher ratio rear differential with the lower ratio transmission, with or without a welded up center differential?

What? Now you want to weld the rear diff too? It's going to handle like crap and get a lot of scrubbing when you turn.
If your transmission's final drive does not match the rear diff, the car will barely move.

[ashino]

Okay, what you need to find is the final drive ratio of the rear gear and see if it matches what you have in the impreza transmission.

Oh, and turn your volcano off. It is screwing up my international shipping.

:-)

so the final ratio of the rear drive in the AT is 2.272? then my rear differential has the ratio 2.272 on the AT wagon?

and the rear diff i need for my 4.111 transmission would have to be a 4.111 ratio

i want to drift my car, either with a good lsd or have the rear diff welded locked. (then i would have a backup diff which would be open)

*EDIT
and im sorry about the volcano, but it´s kind of cool though :P
i´ve red that a nissan rear diff might be good for this but i think that requires some fabrications right?

[DarkPhoenix]

If you get the rear diff out of a S30 Fairlady Z, or maybe out of an S13 Silvia, as they are R160s or R180s.

[jey]

so the final ratio of the rear drive in the AT is 2.272? then my rear differential has the ratio 2.272 on the AT wagon?

No, that's the ratio for REVERSE. No Subaru has such a low final drive. If it's a USDM car then it's 4.111 for 2.2L and 4.444 for 2.5L on the 98 Legacy.

[ashino]

so the final ratio of the rear drive in the AT is 2.272? then my rear differential has the ratio 2.272 on the AT wagon?

No, that's the ratio for REVERSE. No Subaru has such a low final drive. If it's a USDM car then it's 4.111 for 2.2L and 4.444 for 2.5L on the 98 Legacy.

i have both a European legacy and a European impreza. the impreza has the final drive of 4.111, i would think the AT station has the 3.7 something i think.

so if i would put the 4.11 transmission to the lower ratio rear diff it would be like starting in 3rd gear or something...?

is there a 4.111 lsd diff that fits to the 5MT gearbox, drive-shaft and the axles?

[jey]

so if i would put the 4.11 transmission to the lower ratio rear diff it would be like starting in 3rd gear or something...?


No, much worse.

[ashino]

Anyways, which does the subaru impreza 5MT Euro have, the 4.11 final drive or the 3.9 ?

i have found both diffs, now i just need the ratio