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Project junkyard monster! EJ22T block/EJ25 SOHC heads - advice?


thatswhatshesaid
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So, my 2000 EJ25 is toasted. I'll be picking up an EJ22T soon. I want to slap some heads/intake that are correct for my car (so I can keep the stock wiring) on the 22T block and throw a little boost at it.

 

I think I'm going to run the stock internals for the first iteration of this motor. (maybe STi rods) I want to build it for a reasonable amount of $$$.

 

Issues:

- This combo (with the 2.2 HG) will yield approximately 7.8:1 compression...

*I've never driven a small-displacement car with this kind of CR...is this going to be a real dog until I get into boost? I've driven EJ22T-equipped cars (8:1 CR) and I'm unimpressed with the lack of balls at low RPM.

- Are there other pistons I could use to bump up the CR?

- What about getting the heads decked? (too spendy, probably)

- I can probably run a bit more boost since the CR is so low, right?

 

Any advice here? I've seen a bunch of builds with DOHC heads, but...SOHC seems to be far less popular.

 

Thanks, guys...

- Tyler

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low compression means you can run a lot of boost *without worrying about detonation* (there are still other issues, that will NOT be able to solve on stock management).

 

it will still have a lot of lag.

 

Even the big power builds usually run 8.5 or so.

 

 

N/A 2.2 pistons will work. they usually run 9.5, so they'll probably be 9.2 or so with 2.5 heads. that's pretty good for a low-boost setup. but really, it'd be easier/cheaper just to get an N/A 2.2 block. the 22t just has a harder time cooling (closed deck means most of the coolant passages are full of aluminum, there's a reason they don't make those anymore).

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The stock computer will not support much if you plan to throw big boost at it. It simply does not have the capability or programming for boost enrichment and will not "understand" positive manifold vacuum/pressure (higher than atmospheric). There are piggy-back solutions that can handle some of the issues - go over to the legacycentral board and do some searching around there.

 

The biggest problem is that you will need larger injectors to support the boost enrichment but the computer will think you still have the stock small injectors - it will run super rich when it's not boosting.

 

You'll want at least a wideband O2 to tune it properly and I would strongly sugest Exhaust Gas Temp sensors on both banks to monitor for a lean condition. In my opinion those three are the minimum additional gauge requirements for turbo-charging with a non-stock setup. I would also want cylinder head temp and coolant temp in accurate digital format's.

 

GD

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WRX heads, manifold, wiring, & ECU on that 2.2T block.

 

You'll be happy, it will be tunable, and you'll do it correct the first time.

i agree with tex here, i built a hybrid as he described a few years back, 438 wheel horsepower

(there where ALOT of supporting mods) but it was a very drivable car

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Sell the valuable Closed deck block and get another 2.5

 

If you don't want to do any rewiring.....then you really aren't gonna want to do this swap.

 

You need piggyback managment at least, standalone would be better.

 

 

And oh yeah.....did we mention the need to swap front crossmemebers to clear the turbo.....and also a custom exhaust......stock exhaust won't bolt up to the 22t downpipe......if you even have that. you didn't say if you had a whole donor or just and engine.

 

Besides, you could build this combo and get more power with less boost and mods by simply using an N/A 2.2 block and pistons.

 

Unless you are doing a balls out, to the hilt, 300 HP plus motor....there is no reason to use the closed deck block.

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This idea sounds great, BUT...merging the harnesses would be a bear. The wiring and intake for the 2.5 is already in the car...so I'm going to go that route.

 

No, this isn't an idea. This is fact. This is me telling you how do something and have a drivable enjoyable dependable car afterwards. Especially when are talking about boost.

 

Your insistence on sticking with the 2.5 wiring and intake is only going to cost you more time, money, and more importantly a finicky undependable car that you will develop a hatred of.

 

There are people that will do the wiring merge for you. Numbchux on here I believe does a pretty good job. Monstaru might even have wiring available still for a WRX.

 

The cost of "lightly" building your motor you proposed, and getting the WRX stuff and swapping that in should be pretty damn close to the same.

 

We are trying to help you make better decisions based on our past experiences, not just being dicks.

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There are people that will do the wiring merge for you. Numbchux on here I believe does a pretty good job. Monstaru might even have wiring available still for a WRX.

 

The cost of "lightly" building your motor you proposed, and getting the WRX stuff and swapping that in should be pretty damn close to the same.

 

We are trying to help you make better decisions based on our past experiences, not just being dicks.

 

Okay. I get the point. ;) I trust you guys that have been around the block.

 

How about this...in my current position (toasted heads on my 190k 2.5 block)...

- What's the most RELIABLE way to push, say...250 HP at the wheels?

- What's the CHEAPEST way to get to 250 wheel HP?

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Depends if you want boost or not.

 

You are looking at $3000 or so for a WRX setup on the cheaper side.

 

Qman here (Ken @ Delta Cams) put together a VERY peppy NA 2.5 motor. Somewhere I think there is a thread that says how much power that motor put down on the PIA dyno.

 

His setup was a 2.5 block, STI oil pump, STI oil pan, 2.5 heads with some valve work and torque cams from Delta (they do both the cams and headwork). He used a Perfect Power 6 to do a tiny bit of tuning. I can imagine this setup would be a bit less than than $3000. And you'll have quick usable power... not just a ton of power up on the top in boost.

 

I believe these heads at rallitek are the delta ones: http://www.rallitek.com/rasocyhe.html

 

They also sell the Perfect Power: http://www.rallitek.com/rapeecu.html

 

If interested in this setup, definitely talk to Ken @ Delta Cam and Sean @ RalliTek.

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OK. first, 250 hp at the crank or wheels? that's a big difference, and will drastically effect the setup.

 

at the wheels, then yea. what tex said is the cheapest way to get a reliable 250 out of it. BUILT 2.2 shortblock (pistons, rods, re-bored, etc.), USDM WRX heads, intake, wiring, and ECU. We did this on my buddies '95 impreza last summer, awesome combo. he's runnin 8.8:1 compression and a TD04 right now, hasn't seen a dyno yet, but I bet it's in the 225awhp range, and plenty strong enough for 250 with a little more work. I'll do this wiring swap, plug and play for $500.

 

at the crank? that could be done with the 22t/251(or 253, whichever yours has) combo. But you'll need to upgrade your fuel system (pump and injectors, converting to parallel fuel rails isn't necessary, but not hard either and offers a bump in reliability). And management....

 

Don't go PP6 when turbo'ing an N/A car, it's great for adjusting fuel trims, but terrible at timing. If you're doing piggyback, get a GReddy EManage Ultimate (aka EMU). But I would highly recommend a standalone, I'm partial to the Link system, that's what my built, blown 2.2 will be running off of if I ever get around to putting it in something. But any of them will do. This can be done just with some wiring at the ECU, keeping the rest of the harness. I've done this as well, I can do it for you if you want, but it's much easier in the car (don't have to pull the dash).

 

 

 

if you're looking for 150awhp. throw 5psi-ish at your stock system (better with N/A compression). assuming it's a MAF system (I don't remember which years are which), it'll do a great job of compensating for a little boost.

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