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Ea81 power


XTREME RACING
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I have been reading the forum for the last couple of months since I got my 86 Brat and having been learning from the site. It is great!!!!

 

I guess my question is what can I do for more power out my EA81? Like I said I have an 86 Brat it and it only has alittle of 40K miles and NO rust :banana: so I am wanting to give it a little more power using the stock power plant at this time. It is going to be a shop truck for my company so I dont want to go crazy with it yet until I figure out what is possible and who might all drive it.

 

Thanks for any info.

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you can swap on an ea82 hitachi or even the whole intake. typical route is to do a weber swap. you could even swap in an ea82 with monor mod.

 

otherwise if you open up the exhaust a little(custom fab from cat back, your typical off the shelf exhaust pipes bent to fit, and a cherry bomb!) and bump up the timing a few degrees will make it a little more peppy.

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Thanks this is a starting point on the car. I was thinking of the Weber carbs but I like the idea of fuel injection better so I might see what I can find.

 

Here are some ideas I have come up with at this time,

Weber carbs or FI

port and polish the heads

new exhaust system

mill the heads for more compression

new (modified) cam

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I thought about an EJ motor swap but not wanting an EJ motor at this time. If I did anything I would do an EA82T motor swap, I just have to be different:grin:

5 years ago that was all the rage. But now people have seen that its pretty much the same amount of work to put an EJ22 in which has more power without a turbo. And its more reliable. Just stick with the simple stuff. Open up the exhaust flow, stick a weber on it, play with the timing and do the other service stuff. New good oil can actually make a difference on a dyno you know, so all the little stuff adds up.

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And if you get extremely lucky like a certain board member coughPsycocough you might be able to find yourself a JDM EA81. Ive been looking a bit myself but so far have come up dry. As far as i can tell in my research the JDM EA81 had reversed valves from normal EA81s, as in the intake valve is where the exhaust valve is and visa versa. This necessitates a different cam. The exhaust ports are different and it had a dual carb intake. All this added up to 103-108hp depending on what u read.

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And if you get extremely lucky like a certain board member coughPsycocough you might be able to find yourself a JDM EA81. Ive been looking a bit myself but so far have come up dry. As far as i can tell in my research the JDM EA81 had reversed valves from normal EA81s, as in the intake valve is where the exhaust valve is and visa versa. This necessitates a different cam. The exhaust ports are different and it had a dual carb intake. All this added up to 103-108hp depending on what u read.

 

It's not all JDM EA81's like this. Only a select few performance models. I have one too.. I read 101hp on a Ultralite website (their the dudes who picked most of them up years ago and thus hard to fine now.)

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Try living in Washington! We don't have any Suba... oh wait, nevermind! :banana:

No, really, Washington is a difficult place. It's sad how many Subarus you have to pass on simply because of money and space. You can't have them all. :( :-p

 

Btw, Hatchsub, you spelled my name wrong. Psyko. ;)

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According to the Subaru literature the factory dual carb engines were 108 HP. These still were not the dual-port heads though - just better flowing. And it takes more than the heads because as mentioned the valves are reversed so you need the cam or a custom one to match.

 

Subaru also made a variation which I have not seen outside of race/rally prepped vehicles that surely must have put down more than the 108 of the production model. It had carbs mounted to each head rather than to a manifold. I would guess that if it were anything like the RAM engines it was probably putting down closer to 130 to 140 HP. Perhaps even more considering that the Subaru engineers got 120 HP out of the 1.0 liter justy engine for bonneville.

 

GD

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does anyone know where i could find more info on this 1.0L justy motor for bonneville?

 

i'm sure a wicked port/deck job, weber, ported/fabbed intake manifold, hot cam and a good exhaust could get a stock 81 in the 100-110 hp range... it doesn't take much.

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