s'ko Posted February 8, 2008 Share Posted February 8, 2008 I have a 2k OBS with a 5 spd tranny 4.11 final ratio that is on it's last legs. I have a spare EA82 full time 4wd 5 speed tranny w/center diff lock. (NOT D/R:mad: ) w/matching rear LSD. 3.7 final ratio. Would it be worth it to do the swap? Would the locking center diff lock and the rear LSD justify the cost and labor associated with this swap? cost would mostly be an adapter plate and labor would be re-drilling an EA82 flywheel to bolt onto the EJ motor. I probably need to do my clutch at the end of the year so I will have to drop the tranny anyways to get that done. I also have an RX that I could take the D/R out of. Would putting the D/R 5 spd into the OBS make it worth it? Choices are: 1) OBS w/stock tranny replacement and EJ22T RX w/D/R FT 4WD 2) OBS w/S/R FT 4wd and EJ22T RX w/D/R FT 4WD 3) OBS w/D/R FT 4wd and a EJ22T RX w/S/R FT 4WD Ok ready..... set..... debate...... BW Quote Link to comment Share on other sites More sharing options...
Scott in Bellingham Posted February 8, 2008 Share Posted February 8, 2008 :-p :lol: :banana: :-p :headbang: :rolleyes: :burnout: :-p :-p :-p :confused: Quote Link to comment Share on other sites More sharing options...
s'ko Posted February 9, 2008 Author Share Posted February 9, 2008 :cool: :confused: :dead: :cool: :banghead: :eek: :Flame: :cool: :cool: :cool: :lol: Quote Link to comment Share on other sites More sharing options...
Numbchux Posted February 9, 2008 Share Posted February 9, 2008 depends which one you want to have low range (as minimal that low range is). personally, I'd rather have that extra reduction on the turbo car to make it easier to stay in the power band. but then again....you'll be shifting more often, so you may not stay in gear long enough to build boost......hard to say, and depends what exactly you're shooting for out of the 22t (stock? GT40R? ) also, that turbo EA82 tranny will have very short freeway gears. if you spend any time above 60mph, I'd look into getting a replacement EJ tranny (you can always swap the LSD internals into the matching rear diff). Quote Link to comment Share on other sites More sharing options...
Gloyale Posted February 9, 2008 Share Posted February 9, 2008 also, that turbo EA82 tranny will have very short freeway gears. if you spend any time above 60mph, I'd look into getting a replacement EJ tranny (you can always swap the LSD internals into the matching rear diff). Hmmm.. call me crazy, but I would think that 3.7 ratio would make for BETTER highway gearing?? I remeber that my P/T EA82 turbo 5 speed ran lower RPMs on the highway than my carbed ea82 5 speed. Does the EJ box have drastically taller 3rd, 4th, and 5th gear ratios?????? Quote Link to comment Share on other sites More sharing options...
Numbchux Posted February 9, 2008 Share Posted February 9, 2008 Hmmm.. call me crazy, but I would think that 3.7 ratio would make for BETTER highway gearing?? I remeber that my P/T EA82 turbo 5 speed ran lower RPMs on the highway than my carbed ea82 5 speed. Does the EJ box have drastically taller 3rd, 4th, and 5th gear ratios?????? check your manuals. the turbo 5-speeds have drastically shorter 3rd, 4th and 5th gears. the N/A EA82 5-speeds have similar gears to most EJ 5-speeds. Quote Link to comment Share on other sites More sharing options...
Gloyale Posted February 9, 2008 Share Posted February 9, 2008 check your manuals. the turbo 5-speeds have drastically shorter 3rd, 4th and 5th gears. the N/A EA82 5-speeds have similar gears to most EJ 5-speeds. 3.7 is taller final drive so I think you end up ahead. I swear my old 86 Turbo ran lower rpms on the freeway. please, somebody check my math, but by Chux own chart in the USRM, the overall RPMS at highway speed would be lower on the 3.7, EA82t 5 speed. 1k rpms (for easy math) in 5th gear : EA82T 5speed 0.81 5th and 3.7 final= 332 rotations of the wheels EA82 N/A 5speed 0.78 5th and 3.9 final= 328 rotations of the wheels Quote Link to comment Share on other sites More sharing options...
Numbchux Posted February 9, 2008 Share Posted February 9, 2008 the turbo 5th is .871 http://www.ultimatesubaru.org/forum/showthread.php?t=68752 I don't know what's up with your situation....maybe the PT4WD trannies had the taller gears? but I know the RX DR PT4WD one had the puny 1.196:1 low range Quote Link to comment Share on other sites More sharing options...
Gloyale Posted February 9, 2008 Share Posted February 9, 2008 FYI, the Turbo pushbutton 4WD tranny has the same gearing as the N/A 5spd D/R just with a 3.7 final drive ratio. Same goes for the Turbo pt4wd 5spd D/R, except it has a 3.7 final drive and the 1.2 low range. Meaning the PT4WD Turbo trannies have the highest 5th gear. this statement and the last few posts of that thread suggest the PT Turbo trans from 85/86 are differnet than the 87+ fulltimes. Oh, and good catch on the 0.871 It was late last night. Quote Link to comment Share on other sites More sharing options...
mikeshoup Posted February 10, 2008 Share Posted February 10, 2008 this statement and the last few posts of that thread suggest the PT Turbo trans from 85/86 are differnet than the 87+ fulltimes. Oh, and good catch on the 0.871 It was late last night. The 85/86s ARE different from 87+ turbos. And its not a matter of if its FT or PT, its a matter of what year it is, and if its turbo or not. According to the 86 FSM, Turbos have a 0.78 5th gear w/ 3.7 final drive. According to the 88 FSM, Turbos have a 0.87 5th gear w/ 3.7 final drive, regardless of FT or PT. Any other years is your guess. Though, I would suspect 85-86 being same, with 87+ being the same. Quote Link to comment Share on other sites More sharing options...
Gloyale Posted February 10, 2008 Share Posted February 10, 2008 This is from the 86 FSM. Notice that the ratios of the 2wds, and the turbo/4WD are nearly identical, but not excactly. Different # of teeth on the gears means ever so slightly different ratio. Go figure? Quote Link to comment Share on other sites More sharing options...
mikeshoup Posted February 11, 2008 Share Posted February 11, 2008 Well, if we throw 2WD into the mix, then I give up Quote Link to comment Share on other sites More sharing options...
Gloyale Posted February 11, 2008 Share Posted February 11, 2008 It does appear true based on 85/86 FSMs that the P/T turbo boxes are the same gearing as non-turbo. Except obviously final drive, and LO range. But the actual 1st-5th gears and reverse. However, I figured since this is SKO's thread asking about uising Fulltime Turbo trnasmissions, I might as well stay focused on that. So in that spirit, here is the same page from the 87 FSM Quote Link to comment Share on other sites More sharing options...
Numbchux Posted February 11, 2008 Share Posted February 11, 2008 ^ which means my comment above is completely relevant. the FT4WD RX tranny he has will yield very short freeway gears. Quote Link to comment Share on other sites More sharing options...
s'ko Posted February 11, 2008 Author Share Posted February 11, 2008 So now that the dust has settled... Looks like it will not be a great idea for the OBS, since most of it's mileage is commuting and road tripping. The RX might be ok but given the fact that it's got short legs, it may not be the most efficient for the turbo. Right now the RX build is going to be a weekend cruiser/canyon carver. I might do autoX or RallyX with it as well. Short gears not give me the full potential out of the EJ22T so will need to look into a WRX or EJ 5 spd swap for the future. We'll see how this thing behaves first. Thanks for the input. BW Quote Link to comment Share on other sites More sharing options...
Gloyale Posted February 12, 2008 Share Posted February 12, 2008 ^ which means my comment above is completely relevant. the FT4WD RX tranny he has will yield very short freeway gears. Very true, in this case. Didn't mean to stir any dust. We all sorted something out here, and we were both correct in someway. 85,86 Turbo has same gearing as non-turbo 87+ Turbo has lower overall gears, even after the taller final drive. Quote Link to comment Share on other sites More sharing options...
Phizinza Posted February 12, 2008 Share Posted February 12, 2008 Would the locking center diff lock and the rear LSD justify the cost and labor associated with this swap? IMO it is not worth it. Maybe getting a harder packed center diff out of an STi box or something would for offroad. Put an LSD center in the rear. Maybe get a D/R EJ case from Aus, NZ, Europe? Those sorts of things would be worth it. And if anyone here is going to put a EA gearbox in a EJ, why not just use the EJ front casing halves so you don't need adapters..? Quote Link to comment Share on other sites More sharing options...
Numbchux Posted February 12, 2008 Share Posted February 12, 2008 Short gears not give me the full potential out of the EJ22T actually, the short gears will make it easier to stay in the boost (which is why the EA82ts got them..). and for autoX and rallyX where you're not spending any time at speed, it might work perfect! Quote Link to comment Share on other sites More sharing options...
s'ko Posted February 12, 2008 Author Share Posted February 12, 2008 Short gears not give me the full potential out of the EJ22T wow... that's caveman talk right there... Thanks again for the input. BW Quote Link to comment Share on other sites More sharing options...
Numbchux Posted February 12, 2008 Share Posted February 12, 2008 wow... that's caveman talk right there... Thanks again for the input. BW sure thing. it happens to even the best of us BUT, keep in mind, if you use an EJ tranny....you can use an EJ clutch. maybe get your hands on a 4.111 legacy tranny or something so you still have decent gears. Quote Link to comment Share on other sites More sharing options...
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