so im gettting ready to do the 4wd/mt swap into my fwd/at car. I do not plan on this car being an offroad machine, just a street/autocross car. That being said, which tranny would be my best bet for this type of setup?

The Fulltime 4WD trans out of an RX or EA82T.

any MPG differences between running in FWD vs. running in AWD?

Yes, I just switched from a PT D/R to a FT 4WD (both 3.9 ratios). You loose a little in mpg but the gain in traction is well worth it IMHO.

you did notice an increase in traction? wow im suprised.

The Fulltime 4WD trans out of an RX or EA82T.

 

No. The FT4WD center diff is terrible on the street (open=spinning front tire). and EA82t gearing sucks (tall first gear and short 5th....who came up with that idea!?). You'll be VERY disappointed if you go this route......ask me how I know

 

 

only way to go, is an EJ box. Get a 4.111 5MT (most common in first-gen, '90-94 legacies), the VLSD center diff will give you the best handling and traction, 4.111 axle ratios will give you some nice torque at low speed, and the 1-5 gears are perfectly matched to the EJ22.

Edited January 10, 201115 yr by Numbchux

Absolute best is a USDM STi with custom tuned DCCD controller.

 

But, what is your budget?

for the amount of fabrication that would be required to stuff a 6-speed into an EA81 trans tunnel. And we already know he's just using an EJ22. No, 6-speed would just be a giant waste of money.

Sorry, I didn't see here where it stated what his budget, fabrication skills or engine was, just what the best transmission was, so I provided my opinion.

Well then you should have recommended putting an Allison in, It would be just as ridiculous of a suggestion.

 

Going with an EJ AWD 5mt eliminates the need for an adapter plate and redrilled flywheel, so those savings make up for the additional work setting up axles, shifter, crossmembers, and driveshaft. You would need to do that work anyway swapping any transmission into an EA81 body.

 

The full-time 4wd trannys are kind of limited, the traction sucks for hard acceleration while cornering, so you have to lock the center diff, at which point you might as well have used the 2wd/4wd tranny. The VLSD in the center diff of the EJ tranny makes a nice compromise.

You can get the best best of both worlds by taking an EJ 5speed awd and either a 3.7 or 3.9 single range 4wd ea82 trans then put the insides of the ea trans into the case of the EJ trans and use the ea tail shaft and internals the case is the same as the ea82 at this point you can use the stock push button for the 4wd or modify a D/R lever.

 

If you choose to use the 3.9 gear S/R trans you wont need to mod your axles but if you use a 3.7 gear s/r you will need to switch the front axles to fit 23 spline IIRC that is what the turbo trans has.

 

IMHO i think this is a good way to go because if you lose an axle you can still make it to help or home, no vis coupler, selective 4wd, and you can use an upgraded clutch and pressure plate because of the EJ bellhousing.

 

Ask me how i know

 

Just my .02 Rob.

what is required as far as custom axles for the ej trans?

Ok so here is what I have decided. I will run just the factory EA81 4 speed d/r until I do an EJ swap, and the use the EJ tranny.

You can get the best best of both worlds

 

not really. you'd still have the goofy EA82t gearing, and an open center diff! You'd have the better clutch, but with an EJ22, an XT6 clutch would be just fine.

Ok so here is what I have decided. I will run just the factory EA81 4 speed d/r until I do an EJ swap, and the use the EJ tranny.

That's the most logical choice. The EJ drivetrain in an EA81 body makes for a much better power/weight ratio and the AWD works well. You can run a limited slip rear differential if you switch to EA82 axles in the rear, and by mixing and matching cv's and inner stub axles you can run newer VLSD's from 2000+ winter package legacys and WRX"s.

No. The FT4WD center diff is terrible on the street (open=spinning front tire). and EA82t gearing sucks (tall first gear and short 5th....who came up with that idea!?). You'll be VERY disappointed if you go this route......ask me how I know

 

 

only way to go, is an EJ box. Get a 4.111 5MT (most common in first-gen, '90-94 legacies), the VLSD center diff will give you the best handling and traction, 4.111 axle ratios will give you some nice torque at low speed, and the 1-5 gears are perfectly matched to the EJ22.

 

Agreed.

 

But the EJ gearbox is wider than the EA 5sp 4WD box. And if the EA81 is a manual FWD you will find you have to chop and stretch, or cut the trans tunnel out completely and replace it. There isn't enough room in there to fit a 4WD box without serious work. As you've seen from my website I am sure. With that said, I'd still go a 4.11 EJ AWD box.

 

But if your budget is screw all, and you don't end up going an EJ engine, then you can run a 4WD 4sp which is a smaller box and would be easier to fit. Just run it in 4WD on the black top when you need it. I had a 4sp 4WD box in my Brumby and I done over 2000km on the road with it. Then went racing offroad 3 weekends as seen on my YouTube profile... They are strong boxes. But it did eventually blow second gear.

Edited January 10, 201115 yr by Phizinza

personaly i like the 3.7 turbo gears as most of my driving is on the freeway not much racing and i like the longer gears.

 

As for the xt6 clutch stuff its not easy for everyone to find. I compleatly spaced that you have a Fwd car and the 5 speed legacy trans is alot wider.

If you could have started with a 4wd ea81 car the ej trans will fit in easy becasue the early ej trans has almost the same specs as the EA82 4wd trans with exeption of the shorter tail if you go with a 5 speed swap you will need to have a custom driveline made you will also need to swap the inside DOJ cups to mach the trans you choose the only ea82 trans that matches the ea81 is the 3.9 the 3.7 shares the spline count with the legacy 4.111.

 

Cheers Rob.

Edited January 11, 201115 yr by subaruguru

personaly i like the 3.7 turbo gears as most of my driving is on the freeway not much racing and i like the longer gears.

 

also false. The EA82t has a .871 5th gear, compared to the EA82/EJ .780 5th.

 

So final drives in 5th are as follows. EA82t: 3.227, EA82: 3.042, 4.111 EJ: 3.206. Despite having the tallest axle ratio of any of those options, the EA82t 5th gear makes it the worst option (shortest gear=highest rpm) for freeway use.

 

And, since they all use a 3.545 first gear, that means with the 3.7 axle ratio, the EA82t also has the worst option at low speed.

 

 

 

Words can't describe how horrendously disappointed I was when I first drove the FrankenWagon with the EJ22 and RX trans combo. Crappy gearing, and lots of front tire spin on the AutoX course from the open center diff.

 

 

 

 

 

 

 

 

 

I was not aware, however, of the difference between a FWD and 4WD EA81 trans tunnels. That sucks....

im dealing with a car that is currently an Auto trans...i hear that it has a bigger tunnell (according to Phizinza's site)

"Words can't describe how horrendously disappointed I was when I first drove the FrankenWagon with the EJ22 and RX trans combo"

 

I was told the RX trans and the ea82 turbo trans are different both 3.7 finale but different gears.

 

Im not bagging on your facts but i just prefer the 3.7 turbo 5 speed i like the gears and my rpms are lower than with a 3.9 trans and i have had 2 cender diffs fail on me in 4.111 and i like the safty net of if i lose an axle i can still make it to my destination.

 

thanks Rob.

not according to every listing I've seen. the '88XT FSM definitely shows the shorter gears.

 

 

larger tires will bring the rpms down, that's how I combated the issue in my wagon. The 4.111 gearset that I had in my XT6 was muuuuuch better. had zero desire to have low range back.

 

axles don't really break at stock height without a lot of extra power. If you don't do any maintenance and drive it for tens of thousands of miles with a destroyed boot and completely dry joint, it'll click and bind. But I've never seen one actually leave someone stranded.

well you learn something everyday thanks for the tips.

 

Rob.