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froej25

EA82T / EA82 buildup for BRAT

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Hey, look at that, for once a title that's all caps and actually should be... Weird. Anyway, here's the question:

 

My little bro just got his first Sube, an '84 BRAT (*sniffle* they grow up so fast...). It has the EA81 carbed engine- now, its not in optimal running condition, but wow, its gutless. A quick trip to the local junkyard revealed 5 older Subes (3 Loyales with EA82s, 1 older wagon with an EA82, and (yay!) a GL-10 wagon with an EA82T). They may have more hiding in there somewhere; they used to have a turbo XT, but it may have been crushed years ago. Unfortunately, the one EA82T is in pieces (the turbo is in the back of the wagon, engine and heads are still assembled but the intake tract is not complete); I probably can assemble the pieces, but it will definitely require a rebuild; I look on the positive side of this though; it may give me the oppurtunity to make a better engine out of the deal. We have a good relationship with the guys at the junkyard, so they will probably give us good access to the cars. The goal here is to have a reliable, decent performing car on a budget (I don't think he expects to be able to keep up with my '05 Outback XT, just not get run over by a CRX HF). I should mention that our older brother is a motorcycle mechanic for a Honda dealership, and is certified to teach high school auto shop classes, so we have the technical know-how to put things together. Here's my thought:

 

Pressure test the EA82s, select the best one (unless they are dramatically weaker than the EA82Ts? Anyone know this for a fact?)

Take intake/exhaust components from EA82T (seen several references to heads cracking with some frequency, so will use EA82 heads)

Plumb in intercooler (huh, look at that, a Probe GT turbo is sitting right next to the GL-10! What are the odds? :) ).

Get larger fuel injectors- does anyone know if the external dimensions from the XT's flat-6 or EJ series engines are the same as the EA82, and can they be used?

Is there a larger throttle body that will work on the EA82 without extensive fabricating? Like from a later Sube?

Fuel management- hmmm, this is where it gets tricky. I was thinking one option was a rising-rate fuel pressure regulator; coupled with the larger injectors, the intercooling, and premium fuel, it may be enough to keep the engine in one piece (even with the higher compression of the EA82 versus the EA82T). Otherwise, could go with a Megasquirt; but I've never built one, so not sure if that's the way to go. Also, could add water injection coupled to boost (neat blurb on the Megasquirt page on how to do that, basically you use the boost to pressurize a water tank, so only when the system is generating boost does it spray water into the intake stream. Neat huh?).

 

So, that's my thoughts for now. If anyone has solid experience with any of this, I'd love to hear from you. Its a great little car- err, truck. Err, Bi-drive Recreational All-terrain Transporter (B-R-A-T :) ). Thank you.

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Hey, have this conversation going on NASIOC too, so am just going to post my observations here as well, even if it means I am talking to myself...

 

Well, went back to the junkyard to look around, check out the cars with a little better light (was dusk when I went there before). This junkyard used to have an XT turbo, but I asked them and they said it had been crushed; saw a legacy (with an EJ22), went to look at it, and buried back in the woods further was the XT! Its a rare bird I guess, XT GL-10 auto, 112,000 miles on the odometer. Went and asked the guys at the yard about it; they said since they had forgotten about it, we could just have the car (did I mention we have a pretty good relationship with them :) ?) So, they're going to haul it out of the trees on Friday, and we'll pull off everything we need. I think we should be able to use the rear discs; not sure yet, need to do some research; not sure yet if the front brakes are different either, might pull those too. Also get the computer, wiring harness, radiator, etc. I've seen elsewhere that the rear suspension will bolt right in (not sure if that is accurate), and that the front can be adapted to work. Thanks for the input Calebz; this one apparently has the spider intake (didn't loook because I didn't know such a thing existed until this afternoon, but I can check Friday) so may be able to adapt the XT6 throttle body if need be; sux about not having larger injectors available; and I now have access to two sets of turbo heads, should be able to come up with a usable set. Can't beat the price...

As to why we aren't going to go with an EJ series... First of all, its not my BRAT, its my brothers. What he wants is what we'll do with it. Second, this is a budget project; although the engine cost may not be that much higher (could probably get it for $200 from the yard) we'd then have to get either an adapter plate to mate up to this transmission / t-case, or get a EJ-series trans; also the time needed to fabricate the engine mounts (if that's neccessary; can't seem to find any good info on how to swap drivetrains). And the headache of hooking up the shift linkage, throttle and clutch- ugh. I think staying in the EA family has a lot to recommend itself. Granted, wiring is going to be a pain, but it would be for an EJ also. The EA82T also has the advantage of having a distributor; the EJs don't, so using the Megasquirt (no ignition control (yet)) becomes complicated. As far as reliability is concerned, my brother doesn't drive that far from home, and if it breaks down its easy enough for us to recover it; also I don't think its going to be THAT unreliable, not with intercooler, oil cooler, good maintance, and premium fuel. Yes, its an older engine design; but, hey, its a SUBARU! :) If they're good enough for light planes, they're good enough for me. As far as power goes; yes, it is down 15 hp and 3 lb-ft of torque in stock trim. But, it develops that power lower (1990 EJ22 has 130 hp@5600 rpm, 137 lb-ft@4400 rpm, 1987 EA82T has 115hp@5200 rpm and 134 lb-ft@2800 rpm), this with 7.7 compression and 7 lbs (I think) of non-intercooled boost. I think matching the EJ22s peak numbers should not be difficult, and should be plenty to move the BRAT (considering its stock engine has 73 hp and 94 lb-ft and it only weighs ~2300 lbs). Not looking for WRX-level performance after all; judging by how scary the BRAT is at 60 mph (granted, all original rubber bushings and shocks), I don't think my bro is going to be pushing the performance envelope anyway. Thanks for the comments...

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