EA81T performance page.

[Jerry DeMoss]

Please post your ideas of what mods you have done to the ea81t.

I have read plenty of the ea81t threads that pop up in a search and I want to resurect any thoughts or new ideas. Seems the ea81t doesn't get as much attention anymore but I believe it deserves an overview to address some questions to the ea81t's.

 

First of all what I am working on or have completed:

 

-Porting an ea81t intake with heads soon to follow with ram performance springs.

-Ported throttle body.

-Ea82t turbo,ported intake section of the turbo(cold side and hot side)

 

Exhaust- Ea82t dp. Need to modify the ea81t header to bolt up to the ea82t turbo or try to fit a ea82t manifold to the ea81t engine.

 

Questions or answers apreciated.

[mikeshoup]

The uppipe flanges are different between the EA81 and EA82? I know the downpipe flanges were different, but thought the uppipe flanges were the same.

 

Hm. You ported the Throttle Body? Now that's interesting. Details please.

 

I wish I had time and another car so I could play with my EA81T.

[mcbrat]

I found a pic of the intake....

[RenaissanceMan]

Right now I have:

 

Ea81T heads with Ram Springs

EA81 solid lifter Block with Ram Forged 9.0:1 Pistons, balanced crank, balanced rods, Delta Camshaft.

Extra Pin for the case halfs.

ARP head studs (rated to 180,000 psi)

 

What needs to be done:

Because of the lift of the cam, the valve guides need to be trimmed a little bit, then just bolt on the heads and everything else.

[daeron]

whats so different about the intake ports between the EA81t and the EA82t? if the SPFI from the 82 swaps onto the 81 so easily, it begs the question of whether the turbo manifolds could possibly be exchanged for one another, thus allowing you to simply install an ea81t block into an ea82t car? Of course, the issues of installing the longblock into the chassis have to be overcome. I have no idea what those might be, but i could see possible issues with engine crossmember, maybe axle hookup? Minimal stuff.

 

It seems almost like there HAS to be a good reason it hasn't been done.. is there?

 

otherwise, why no high comp ea81T XT or RX?

[joostvdw]

I highly doubt its as simple as you make it sound, but it can certainly be done. the EA81 fits in the same space as the EA82 and uses the same mounting points, AFAIK the ea81t is MPFI but uses the SPFI mounting points, so you have to swap that with the engine, the SPFI system does not like boost.

 

why hasn't it been done? I don't know, but something that's even stranger to me, people O-ring and put custom pistons in EA81T's but not in EA82T's and then complain about blowing pistons or HGs? Seems to me, somehow, people spend more money on the EA81T then on the EA82T.

[mikeshoup]

whats so different about the intake ports between the EA81t and the EA82t?

EA81T has siamese intake ports with injector bosses in the heads. So the EA81T manifold only has two runners. Now one *could* put the SPFI manifold on the EA81T, but it'd be rather pointless except for maybe a fifth injector

[subyrally]

EA81T has siamese intake ports with injector bosses in the heads. So the EA81T manifold only has two runners. Now one *could* put the SPFI manifold on the EA81T, but it'd be rather pointless except for maybe a fifth injector

 

i thought about that a while back when i was looking at getting a turbo brat.

[hatchsub]

EA81T has siamese intake ports with injector bosses in the heads. So the EA81T manifold only has two runners. Now one *could* put the SPFI manifold on the EA81T, but it'd be rather pointless except for maybe a fifth injector

 

nitrous injector

[Turbone]

The uppipe flanges are different between the EA81 and EA82? I know the downpipe flanges were different, but thought the uppipe flanges were the same.

 

Hm. You ported the Throttle Body? Now that's interesting. Details please.

 

I wish I had time and another car so I could play with my EA81T.

 

You just use the EA82T up pipe, bolts right up.

Well, almost. The mount holes in the flange and head are opposite, so you need to swap the studs. Thats it.

 

The EA81T also has a pressure relief valve on the intake. If the wastegate fails to open, the valve will open. So if you want to up the boost, you may have to remove the valve and block of the hole in the intake.

I never got a chance to do this on any of mine.

Maybe because I didnt want to grenade the engine

[mikeshoup]

i thought about that a while back when i was looking at getting a turbo brat.

It'd probably be difficult. Easier to just swap the throttle bodies and throw the EA81T TPS onto it. Then throw a Megasquirt computer on it in a piggy back mode, and plum in the injector into the fuel supply.

 

Only problem I foresee is if the throttle bodies are different sizes. I know the SPFI is 46mm, but I dunno about the EA81T.

[calebz]

Maybe because I didnt want to grenade the engine

 

 

You really know how to take the fun out of owning a 20+ year old forced induction car

[MSSLGECKO]

Hey, this is an awesome thread!! I've been looking for EA81T upgrade ideas for a while, but the topic doesn't come up often.

 

I still haven't got my head around the cone filter modification: How do I do it?

 

Another question:

Looking at the pic. on pg.2, I see a bar that goes between the struts and bends in the middle making room for a spare tire. Is that a functional bar? Also, what is the nature of the sensor w/ a plug mounted on it? I removed it from my T-Wagon and never replaced it because it didn't appear functional.

 

[carfreak85]

I agree that the EA81T is an under-loved power plant. Hell, it was only avalible in a very limited number of markets for perhaps the better part of two years. Sort of a Subaru performance anomaly like the SVX or GC 2.5RS.

 

On a side note, the crossover pipe flange is identical between the EA81 and EA82 turbos except where they .bolt to the head. Downpipes are identical. Legacy turbos (VF-11) have WRX style flanges. EA81T crossover pipe houses the O2 sensor while the EA82T O2 sensor is in the downpipe.

 

Seems as though I'm being left behind in the battle of beefy internals. All I have done so far to the engine are bolt ons:

 

Cut bottom of the intake box + K&N panel filter

SS manderal bent header 1.5" primaries, 1.75" uppie

3" DP

2.5" exhaust with Flowmaster muffler

 

I have been stocking parts for various engine related projects that will be added shortly such as an intercooler, EBC, turbo timer, uprated turbo and RRFPR. Just need to get some additional gauges and support hardware for these mods to go on. Once I start with my turbo coupe project, I will have a spare engine to pull apart and build up. Currently I'm finishing the clear coat on a WRX hood scoop and splitter.

 

Ea81T heads with Ram Springs

EA81 solid lifter Block with Ram Forged 9.0:1 Pistons, balanced crank, balanced rods, Delta Camshaft.

Extra Pin for the case halfs.

ARP head studs (rated to 180,000 psi)

WOW, thats some nice hardware!! How did that affect your wallet? Not trying to be rude, but I have another source for valve springs, etc. and just want to be able to compare prices.

 

I'm also not convinced that porting is a worthwhile mod for these engines. While I am sure it would help some on a N/A engine, these little guys are not flowing enough for ports and TBs to be a restriction. Plus they are turbocharged, so much of the port work would be negated simply by having positive manifold pressure. But I'm still interested in learning more about these mods for future application.

 

Looking at the pic. on pg.2, I see a bar that goes between the struts and bends in the middle making room for a spare tire. Is that a functional bar? Also, what is the nature of the sensor w/ a plug mounted on it? I removed it from my T-Wagon and never replaced it because it didn't appear functional.

The spare tire support is non-structural, but does have a heat sheild for the turbo. That sensor is your ambient air temp sensor. HOOK IT BACK UP!

[Ross]

 

 

I'm also not convinced that porting is a worthwhile mod for these engines. While I am sure it would help some on a N/A engine, these little guys are not flowing enough for ports and TBs to be a restriction. Plus they are turbocharged, so much of the port would would be negated simply by having positive manifold pressure.

 

 

Agreed, mostly- I think some minor work around where the heads and manifold meet is probably worth while - the holes are very poorly matched (were on mine anyway) as are the gaskets. But going all out with porting on a forced induction engine isn't necessary.

 

Just put a new oil cooler on mine - much better, the oil stays clean looking now and pressure stays right up even after a long hard run at ~175km/h (in a four speed!!). Runs smoother like this too.

[greencar294]

anyone built custom headers and exaust for a brat?

[ShawnW]

Jerry: That pic shows the air filter I still have.

 

Figure all this crap out and then lets do it to mine.

[Jerry DeMoss]

Jerry: That pic shows the air filter I still have.

 

Figure all this crap out and then lets do it to mine.

 

Gladly! One thing I have noticed this far along with getting the ports all matched up is that they should really help alot to get flowing evenly. Lots of restriction in a little aluminum here and there. I am interested to see how the ported throttle body and turbo help out the whole deal. Exciting to hear others have used the ram valve springs!

[Turbone]

anyone built custom headers and exaust for a brat?

 

Sorry, but this has nothing to do with this thread. If you have a question please start another thread.

[carfreak85]

I'm interested in what other owners think about ceramic coatings. Specifically for the combustion chamber. I know that one of the heads on my engine has a crack ala EA82T, but the subie specific repair shop said it wasn't anything to worry about. I know Swain has a coating that doesn't seem too expensive.

 

Does anyone have any opinions on this?

[Jerry DeMoss]

I'm interested in what other owners think about ceramic coatings. Specifically for the combustion chamber. I know that one of the heads on my engine has a crack ala EA82T, but the subie specific repair shop said it wasn't anything to worry about. I know Swain has a coating that doesn't seem too expensive.

 

Does anyone have any opinions on this?

 

I would love to give that a try sometime.....For now I bought header wrap for the header/turbo manifold and dp. I will see little gains I am sure but the under hood temps may be a bit lower. In the future I will definately give that a try.I will be doing that on my ej22t build. We shall see. I definately want to try that for sure.

[SuperNova]

So can a turbo be put on an EA81 SPFI? Like a blow-through spfi turbo setup. And if so, how much boost can it handle?? Has anyone done this?

[carfreak85]

This is the wrong thread for that question. Please start a new thread in this forum or the retrofitting forum. This is a thread about factory turbocharged EA81s. Sorry if that came off rudly.

[SuperNova]

This is the wrong thread for that question. Please start a new thread in this forum or the retrofitting forum. This is a thread about factory turbocharged EA81s. Sorry if that came off rudly.

 

Dude, don't be a hypocrite! There is alot of mention of EA81, EA81T, and EA82T in this thread, i was simply asking a question to members that obviously know alot about this subject. I wasnt trying to change the topic to ceramic coatings like you.

[carfreak85]

So can a turbo be put on an EA81 SPFI? Like a blow-through spfi turbo setup. And if so, how much boost can it handle?? Has anyone done this?

Quick search found this:

 

http://www.ultimatesubaru.org/forum/showthread.php?t=77362&highlight=spfi+doesn%27t+like+boost

 

http://www.ultimatesubaru.org/forum/showthread.php?t=67572&highlight=quattro+san

 

http://www.ultimatesubaru.org/forum/showthread.php?t=23639&highlight=quattro+san

 

http://www.ultimatesubaru.org/forum/showthread.php?t=80422&highlight=turbo+ea81

 

Different cam, pistons, heads, and entire intake/turbo ect. The block is the same as any other hydro lifter EA81 block.

 

Mounting the turbo in it's stock config would require the turbo engine cross-member, all the wireing, the ECU, intake, turbo, and all the exhaust bits. Also have to convert the existing fuel system to high pressure for the fuel injection.

 

Or you could do a carbed turbo and make it all custom - but that's never been done that I know of, and would require a lot of old-school turbo knowledge that few people have now.

 

GD

As for the ceramic coatings, I was talking about it as it pertains to EA81Ts and preventing future cracking of the combustion chamber, sorry for the confusion. EA81Ts are my bread and butter, so don't think that I'm trying to lead this thread off track.