legacycentral bbs

now i know what everyones response is going to be, search, and my response is i already have and have not found what i want... i am curious has to if a 6 mt sti transmission will fit into a 1990 subaru legacy n/a. if not is there anyway that i can lower my crusing rpms for highway use... by combining a different or the same transmission with a different or the same rear differental... im open to all and any ideas and comments, thanks

You could go to 3.90 ring and pinions, which would lower your cruise rpm by like ~250 rpm.

The STi unit does fit, but it requires quite a bit of work to do so, and is also very expensive.

First off...someone help me understand. Doesn't the 6mt have the same 4.11 gear ratio (I think there was an option 4.44 final). Even if the tanny had more gears wouldn't it still cruze at the same RPM with the same GR? You would just be shifting more right?


I assume your ultimate goal is to get better fuel economy or to be "easier" on your engine?

I saw a post on here somewhere that had a guy talking about using some VW tranny or something. He claimed his mileage was much better. But I think that would be a lot of modding to get a little better mileage.

On the other hand if you are AWD which I am guessing you are...you could always drop the AWD and put a FWD tranny in. Its kinda backwards from what everyone else here is trying to do..

The FWD tranny has a final GR of (IIRC) 3.70 (don't quote me, I know its lower than the AWD's). I get around 34-36 MPG (highway/backroad) in the warm weather and around 31-33 MPG (highway/backroad driving) in the winter (There is NO city driving out here so I couldn't even begin to tell you). Might be cheaper to just find a FWD legacy rather than to try swaping your AWD out (unless you sell the old AWD stuff). Living here in NY I can tell you the snow has to get pretty deep to stop my FWD. A good set of snow tires helps out too.

turboleg: in the 6 speed sti transmissions, the ones im looking at, the fd ratio is 3.9 and the final gear is lower therefore lower rpms at cruising speed. also i live in north idaho and in the winter time 2wd is not really an option, thanks though...

some of my reasoning behind this idea is yes better gas millege on the highway at 75 but then lower rpms if i wish to go faster... given i have enough power, which i will soon. another reason is that these transmissions can haldle more power then the stock n/a trannys, and since i plan on building the motor up i am going to need a transmission that can handle the power, might as well do it right.

i am looking into an 04 sti 6 speed, does anyone know any information on these? such has 75 mph cruising rpms, and compatabilitiy with motors and my car...

One of the members of this board (93ForestPearl) has an STi 6 speed behind an EJ22T in his Legacy...I am sure he can answer all of your logistical questions