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EA82 engine to EJ trans adapter


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Umm....yeah...the reverse of what everyone else wants.

 

Im planning on having an EA82T sitting infront of an EJxx trans...5 or 6spd STi trans.

 

Now...what I need...is the adapter plate...or some ideas. And....will the EA82 turbo clutch work on an EJxx trans? Since i dont have an EJ trans here, i cannot asnwer my Qs....I DO have an EJ22 engine...and EA trans....but...not the opposite. :-\

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why? I don't think you'll ever have the power(like over 300 I'd say) to destroy the EA case. but I do think that the spline count it the same on the EJ trans as it is on the EA clutch disk, but I'm not sure about that

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for better gearing and the viscous coupling center diff. If i get the 2005 STi trans, it will be truly indestructable, and the front diff is better than the 04....its an LSD as well.

 

3 non open diffs and excellent gearing.

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what i mean by that is

if you have a turbo, you obviously want power, so the only thing extra that you would have to do is wire up the ej22, wich i hear is pretty easy. and then you got more power, and more reliability. too much trouble, just to keep the ea82t, and extra stuff you already have.

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but would it really be better gearing for the EA-82? (I've never really seen a spec sheet that had the ratios on it for the 6 speed) I'd hate to spend all that money for the tranny and its no better than what you had before. but H*** why not? go ahead and try it

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yep I just looked it up it has 3.900:1 for the final drive and the rest as follows

1st 3.636:1

2nd 2.375:1

3rd 1.761:1

4th 1.346:1

5th 0.971:1

6th 0.756:1

anybody know what the WRX 5speed and the RX box has in its guts? haven't found those yet

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im not sure if the ratios were the same year to year, but in 1986 the gearing for the fwd trannies is as follows

 

1st=3.636

2nd=1.950

3rd=1.344

4th=0.971

5th=0.783

rev= 3.583

 

the gearing for the turbo nad 4wd trannies is

1st=3.545

2nd=1.947

3rd=1.366

4th=0.972

5th=0.780

rev=3.416

high is 1:1 and low is 1.196 in the turbo models and 1.592 in the rest.

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I've found that the gearing of the RX is surprisingly close to that of my 2.5RS (which has very tight gearing). I base this not on actual ratios, but the fact that they have similar redlines and hit almost identical speeds at redline in the first few gears (rev-limiter on the 2.5RS is 30mph in 1st, 50 in 2nd and 75 in 3rd). The STi also has similar top speeds in the first few gears but has a higher redline so the actual gearing is tighter.

 

So, in other words your gearing should already be on par with a 2.5RS (which has a much closer ratio than a WRX or Legacy and isn't too far behind the USDM STi ratios). Which means to get better gearing you are looking at a $5000 USDM STi gearbox or STi-RA gears in a WRX or 2.5RS tranny (not as much as the STi gearbox, but still several thousand dollars). If you are simply doing this for gearing, I don't see it being worth the cost (or if your current gearing is wider than that of my 86RX, maybe you need a PT4WD D/R tranny (or some other EA82 tranny) instead).

 

Also, don't forget your dual-range tranny (you do, have a D/R tranny, right?) gives you "half-gears" that you won't get with an STi gearbox. Perhaps try something like: Launch in 1st 4WD LO, shift to 2nd (still in 4WD LO as you simply won't have time to change it yet...1st HI goes by fast enough as it is...lol), then shift up to 4WD HI when you run out of revs and that should be enough gearing to get you around most local autocross courses, but with a better launch than using just HI range.

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Now that I do remember...the RX that runs is pretty gutless (you drove it shane, remember? LOL)

 

I have an XT Turbo FT4WD single range trans in the GL-10, IDENTICAL gearing to all other turbo 4wd trans that are 3.70. The XT 2wd turbo has taller gearing, 140 at 6000. Where at the RX's and such is 130 at 6500...outch.

 

i belive the XT6 has the taller gearing for 140~145 at either 6000 or 6500....

 

Back to the RX, the 1st RX i had...well, still ahve, when it ran, i did the hi-lo hi lo thing all the time. i loved it. It DOES make a real difference. With the Gutless RX, it dont matter....still slow...gutless...forward motion....eh...I tihnk its engine it ready to expire.

 

with the 5 lug parts and ej trans, i am simply exploreing possibilities....as...I plan to have 300 CRANK HP from a DAILY DRIVEN EA82T...does teh RX box handle it? Maybe...i dont know. I AM confidant....but incase it does not, i DO want to have a box that does. We know that the WRX trans supposibly craps out under extream use around those numbers, and I simply dont know about the RS box, although, SHane, you abuse yours alot, right? ;)

 

The USDM STi and over seas STis are MADE for that power treatment. So...when I get to that point, I want to be ready if the RX boxes dont work.

 

I ahve considered re gearing the boxes and installing an VC center diff and doing soemthing with the front, either VLSD or clutch type LSD....

 

Time will tell...

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the problem might be that the turbo ej series trannys use pull style clutches, and apparently they're only compatible with pull style trannys, and vice versa. This means you need tranny, clutch, pressureplate, and flywheel matching in order to work. Are there pull style ea clutches? Do you think an ej series pull flywheel would mount? How many holes hold the ea series flywheel to the crank? and whats the offset between them?

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Seems kinda pointless to me. Whatever slight gain you get from the EJ tranny is going to be negated by the extra weight of the EJ tranny. Also the heavier parts inside. I bet the EJ trans takes more HP to operate than the EA trans.

 

Besides gearing what other advantages are there?

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weight issue....probably....I do get the advantage of a constant center diff, and the aftermarket support for gear sets and front LSD, and the rear as well, as I would ofcourse use the diff thats supposed to come with that trans.

 

In the end....I bet i will never have and EJ trans in the wagon unless there is an EJ257 infront of it.

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and I simply dont know about the RS box, although, SHane, you abuse yours alot, right? ;)

 

I try not to...really...LOL ;)

 

Regardless, though, conservative flywheel estimates (based on the AWD dyno runs we did in Mooresville) puts my 2.5RS at 192hp and 204lb-ft which is a bit below what you seem to be planning for the RX.

 

FYI: From what I've heard the actual case and many of the inner parts are actually identical between the 2.5RS and WRX trannies with the primary differences being different gears (as the WRX has completely different gear ratios) and a pull-type clutch setup.

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I should mention that guys down here swap ea and ej gearsets between the cases and mix and match gearing etc etc..the sets are completly compatible subaru only seemed to alter the gearing the cases and the gear material..between ea and ej..oh and the front diff and center diff where applicable also seem to differ but as I said input and output shafts seem to have identical arrangements...

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that is what we have, a std EA box, with wrx ra gear kit + diffs , 12kg viscous centre diff (4.11) and a rear LSD from an impreza it is worth the effort (not that I built it). the car has only a 175-180 top speed, but it gets there very quickly. 4th tops out at about 115-120...and 5th pulls strongly to 175-180

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that is what we have, a std EA box, with wrx ra gear kit + diffs , 12kg viscous centre diff (4.11) and a rear LSD from an impreza it is worth the effort (not that I built it). the car has only a 175-180 top speed, but it gets there very quickly. 4th tops out at about 115-120...and 5th pulls strongly to 175-180

 

thats in KPH ofcourse....right?

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I should mention that guys down here swap ea and ej gearsets between the cases and mix and match gearing etc etc..the sets are completly compatible subaru only seemed to alter the gearing the cases and the gear material..between ea and ej..oh and the front diff and center diff where applicable also seem to differ but as I said input and output shafts seem to have identical arrangements...

 

I had heard that the design that the Impreza tranny used was "old" but didn't realize it was to the point that it was interchangeable with older trannies! Sweet. :)

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