legacycentral bbs

Hey guys i'm new to this forum and i was wondering if it would be at all possible to get my '91 legacy L sedan NA to 300 hp or more. I'm posting here because i thought it would be a good place to start upgrades. So far the only mods i have are 15" rims, tint, and a pioneer premier headunit. Thanks in advance!!

Welcome to the BBS.

300 chp is attainable on your stock motor, albeit there are a lot of supporting mods you will need. 300 whp is also attainable but you are looking at a lot more time and money investment.

Your fist step to this should be to take some time and do a lot of searching in the engine forum. There are plenty that have achieved this goal and provided tons of documentation.

Search and if you have specific questions, ask then.

Again welcome to the BBS.

300hp on an NA? Impossible without forcing more oxygen into the engine

^^^ Ditto, or swapping to a 2.5 shortblock, headwork, cams, intake, etc.

Yeah, start saving for a turbo motor swap. JDM motor sets are all over Ebay. Trying to get that much power out of your NA 2.2 is gonna get real expensive, and very short-lived. A 220hp EJ20G swap is pretty simple, and a few mods will boost output nicely.

BTW I was very careful to say "more oxygen" into the engine because technically thats what nitrous oxide does.

I think Aerotech has the best idea. A completely stock ej20 swap would be very fun and involve VERY little work and no tuning for an instant 170% of the original power.

mmm a turbo motor swap...ok

but is it not possible or is it impractical to just put a turbo on an NA engine? would there not be enough space to put an intercooler and turbo or would there be another limiting reason

There's tons of other limiting reasons, mostly for efficiency and longevity. Search, and you'll see our many arguments on this issue.

t3h L3g4cy wrote:mmm a turbo motor swap...ok

but is it not possible or is it impractical to just put a turbo on an NA engine? would there not be enough space to put an intercooler and turbo or would there be another limiting reason

you're only limiting factor would be reliability. i'm guessing your car has over 150k miles. and turbo-ing a 150k+mile car can cause problems.

Don't get us wrong, you absolutely CAN turbo your NA motor... but if you're looking for 300hp out of it, don't expect it to last more than a few blocks. 150-180 hp, no problem. For the boost levels you'll be pushing for 300hp, you NEED a closed-block case, like the EJ22T or EJ20, or a STI 2.5 short block, an engine management system, bigger injectors, fuel pump, etc. Also a turbo front crossmember so you can use the turbo exhaust.
The NA 2.2 is an open-block case, and is inherently weaker. Much cheaper to produce for the mfg., but not real well suited to high HP setups.

Actually, you might want to search on NASIOC too, 'cause I know many of those guys were turbo charging their 2.5RS Imprezas before the WRX got to the US.
http://forums.nasioc.com/forums/index.php

Aerotech wrote:For the boost levels you'll be pushing for 300hp, you NEED a closed-block case, like the EJ22T or EJ20, or a STI 2.5 short block, an engine management system, bigger injectors, fuel pump, etc. Also a turbo front crossmember so you can use the turbo exhaust.
The NA 2.2 is an open-block case, and is inherently weaker. Much cheaper to produce for the mfg., but not real well suited to high HP setups.

You really don't need a closed deck block to make 300hp...whomever started that myth should be kicked in the grill. It takes a lot of pressure and stress to make the cylinder walls walk, which is the main advantage of having the closed-deck case; in that it doesn't walk near as easily. The EJ205 WRX block is open deck, and the EJ257 is semi-closed. The 257 makes 300chp stock...and it's not closed deck. Also...as far as the turbo crossmember goes, you could just make a custom up-pipe to use the NA manifold and run it around the NA crossmember.

Mainly, as far as turbocharging goes...you need to make sure that you have friendly air/fuel ratios on boost (no more than 12.5:1) and that the incoming air stays cool enough (read: intercooler). The more compression you have, the more prone to ping and detonation...so, if you are planning on running much boost, or a large turbo; low-compression pistons would be a good idear.

OK, I did overstate the fragility of the NA motor, sorry...

Oh no worries...I just didn't want the original poster to be deterred from achieving his goals.


That said...closed-deck = teh sexorz

If you do some good research on things like car-part.com and look for EJ22T engines, you can get lucky (like I did) and find one for cheap.

I found my EJ22T from a 92 Legacy SS with notes reading 81 thousand miles, no start which means when it was removed they were unable to start the engine due to the vehicle not having a transmission.

I picked it up for $400 + $200 shipping back in 05; finding another one like that would be hard, but you could get lucky.

Having the closed deck block is definitely a benefit because once you're turning 300 to the wheels, you may not want to stop (unless you get frustrated with finding a transmission that can put up with more than that)

haha wow guys...thanks for all this info I appreciate it. I searched a little bit before i joined but my research only hit like the tip of the ice burg... well, i guess i should list out all the things i want to do to my car and wat i plan to get out of it so that u'll know wat i'm planning.

Already stated it's a 91 legacy L sedan and it has no real performance mods. I want to get coilovers (i will post in appropriate section ) cuz when i have passengers and i'm going through turns, the suspension squeaks like crazy lol so my passengers all freak out. I've seen youtube vids of subarus that have 3" mufflers and sound so nice and i want that to come from my car And the last bit, is a turbo. Gotta love that turbo sound.

But since i've had my car for almost 3 years and the original engine has over 194k miles, i would think that it would be a bad idea to put a turbo on it since, like u guys said, it would put more stress on the engine. Not only that, my trans is giving me a crunching noise in 3rd gear and from looking around i realize that it was my fault for not putting in the correct sae gear oil T_T so i've been double-clutching every time. Going to replace the gear oil soon maybe with redline, lucas, or mobile. idk yet.

So i guess from all your input, i should save up for an EJ22T engine, get the turbo crossmember, (not quite sure wat that is. is it the pipe that takes the exhaust gases from the manifold back up to the turbo?) exhaust system and get lucky?

t3h L3g4cy wrote:So i guess from all your input, i should save up for an EJ22T engine, get the turbo crossmember, (not quite sure wat that is. is it the pipe that takes the exhaust gases from the manifold back up to the turbo?) exhaust system and get lucky?

the crossmember is what the engine sits on. the two engine mounts bolt to it.

555BCTurbo wrote:

...whomever started that myth should be kicked in the grill.

...The EJ205 WRX block is open deck,

Mainly, as far as turbocharging goes...you need to make sure that you have friendly air/fuel ratios on boost (no more than 12.5:1) and that the incoming air stays cool enough (read: intercooler). The more compression you have, the more prone to ping and detonation...so, if you are planning on running much boost, or a large turbo; low-compression pistons would be a good idear.

^^^^Yep. I'm running two different open deck motors. One with expensive rods and pistons, the other with factory STi bits. The one with Crower rods and Wiseco pistons (yes open-deck block) lives at 20psi daily on a TD06H-20G and used to run a GT32/35 before that turbo took a shit recently. The Subaru open-deck is perfectly suited for daily driving at higher power levels. Now if this was a track car, well then it would be a poor, poor choice.

As equally important or even more so, is ignition advance/spark. This is a lot harder on the motor than just a nice AFR. Detonation from overly advanced ignition will kill a motor quickly.

Concerning the original question - LOL! If you've got some extremely DEEP pockets then yes....300 REAL CHP in NA form is possble. If you are like the rest of us, just turbo it and be done

HAHAHAHA well no i don't have deep pockets at all. I'm struggling trying to get my friends some gifts -_- W00t turbo's here i come

Finally someone mentioned the real reason this guy shouldn,t turbo his engine: compression ratio. Add that to your list of things to search about.

As for the open deck myth? Blame the interweb. Mike shields wrote an article about why the open deck ej25 wasn't strong enough for high powered turbo builds. Next thing you all open deck motors suck!

Quirt crawford was boosting ej22e na blocks and putting out 300+chp long before we had a usdm wrx. He was dropping the compression ratio but he was also boosting the hell out of them. The ej22e with ej25 heads on it has compression in the mid 8's. It's the cheap option for boost that just doesn't get enough love...

Which ej25 heads, specifically? This may be in the future for me.

beatersubi wrote:Which ej25 heads, specifically? This may be in the future for me.

DOHC 96-99 Ej25. Or, use the early legacy or wrx EJ20G heads. I am personally using SOHC ej25 heads because that's what my supercharger was built around. However, for turbo application using the DOHC heads is simpler...

Do the SOHC EJ25 heads still maintain the engine as a non-interference engine? DOHC? Does this change with 22T internals?

tmarcel wrote:Concerning the original question - LOL! If you've got some extremely DEEP pockets then yes....300 REAL CHP in NA form is possble. If you are like the rest of us, just turbo it and be done

No amount of money will break the laws of physics. There is only some much oxygen in the atmosphere... therefore only so much power that can be generated from burning that oxygen in a given volume. You need more displacement to get more horsepower (without forcing induction). Given current technology you can expect about 110hp/L with LOTS of research. So you'd need at least 2.7-2.8L just to make 300hp at the crank. At the wheels you'd need at least 3.7L in our AWD systems.

So with gobs of money you could make approx. 230-240 hp at the crank with a 2.2L engine, about the same as the crappy US tune 2.0L WRX engine. I'd go for the boost personally.

Brat4by4 wrote:

tmarcel wrote:Concerning the original question - LOL! If you've got some extremely DEEP pockets then yes....300 REAL CHP in NA form is possble. If you are like the rest of us, just turbo it and be done

No amount of money will break the laws of physics. There is only some much oxygen in the atmosphere... therefore only so much power that can be generated from burning that oxygen in a given volume. You need more displacement to get more horsepower (without forcing induction). Given current technology you can expect about 110hp/L with LOTS of research. So you'd need at least 2.7-2.8L just to make 300hp at the crank. At the wheels you'd need at least 3.7L in our AWD systems.

So with gobs of money you could make approx. 230-240 hp at the crank with a 2.2L engine, about the same as the crappy US tune 2.0L WRX engine. I'd go for the boost personally.

not that i would ever do it BUT what about NOS? that would add more oxygen without going forced induction...

ASC-up,
Most of us consider NO forced induction. You are forcing more air into the system, even though it's not supercharged air like a turbo or blower would introduce.

As for your other question about interference, I believe that all of those options will be interference. I've never understood why that would matter. If you time it right, there's no interference. Simple as pie...

And if you want to see the results of what happens when timing missing on an interference motor, look for my old thread about my Ej20G bottom end, ej22t heads top end. There was some real interference there when the timing belt slipped...