Better intake manifold for my ej22t?

[Subierotic]

Hi, newbie here. I have a 94 turbo wagon, and ive been wanting to increase the efficiency and power of the motor. I do not intend on doing a DOHC head swap, so my question is if any SOHC intake manifold will work for me? Will something from, say, a 2005 forester bolt up? I can have EGR ports welded up, so that is no concern. I'm looking for better bottom end grunt, so longer runners and bigger plenum is what I'm looking for. Any recomendations?

And just so I don't get a bunch of other power recomendations, I DO have a 3" turbo back system on it, and have done coffee cup/snorkus already. I don't plan on bigger injectors anytime soon, so bigger turbo and cams are out of the question for the moment. Just looking to improve the efficiency of air coming in, now that it is going out just fine.

[jefferson]

You might just have the stock one extrudehoned. That is the plan I have for mine. The before and after dyno article I saw was on a mustang manifold and they saw an increase in the low end. They attributed it to the cooler intake charge due to the smoother walls giving up less heat to the air.

I would also recommend the 45 degree airbox mod. Well worth the effort.

Jeff

[kimokalihi]

You said you don't want other power suggestions but an intercooler is going to be your best bet for more efficiency and thus more power. And then finding ways to improve the flow through that intercooler and keep the heat away from it. Coolant bypass mod and phenolic spacers and ceramic coating of the manifold will all help as well.

[Subierotic]

Thanks for the suggestions.

jefferson, I have looked at having exhaust manifolds extrudehoned in the past, but the price scared me away. If I were to spend that kind of money on it, I would like to start out with a bigger plenum intake. But I do agree, that would be a great idea.

kimokalihi, I have thought about the coolant bypass mod, but up here in the seattle area, we see freezing temps quite often during this season, so it would have to be something I could switch back with ease. My next step is to install a set of grimmspeed phenolic spacers that are sitting on the shelf waiting for some free time. I have not read any posts about the spacers to see how people like them, but I know the drop in intake temp and increase in runner length should both be great benefits. The intercooler is a great upgrade, and I hope to pick up an 06-07 unit soon.

Since I have to pull the manifold to install the spacers, I figured I would ask some questions about the manifold so that I may do the swap at the same time.

[kimokalihi]

Here you go. Right up there by you too.

http://seattle.craigslist.org/tac/pts/2816956335.html

I have the phenolic spacers but don't have a before and after comparison since I've had them on since day one. The intake is certainly not as hot as my previous legacy so they definitely reduce temps of the manifold itself. I also have the coolant bypass mod and have driven the car in 20 degree weather with no problems. But do so at your own risk.

I posted a link to a thread on NASIOC forums where they flowtested several manifolds including STI and DOHC and SOHC NA manifolds and aftermarket ones and the SOHC EJ25 tested the best as far as flow rate and variance between runners. Gotta find the link. Or you could search NASIOC for it under intake manifold flow test and it should come up.

[Legacy777]

One thing I'll add from my opinion.....the intake manifold really is not a huge bottleneck in flow restriction. Replacing the manifold or extruding may help, but the gains are going to be marginal for what you have to spend or what you have to do to get it to fit.

The big issue with changing the manifold is getting it to mate up to the heads. Any of the newer manifolds are going to require changing the heads, and I don't know if that's a road you're interested in going down.

For turbo engines, the little efficiency things that you do on non-turbo engines become a much less significant impact comparatively to an increase in boost or lower intake charge temps. A light weight crank pulley is a good example of this. When my car was non-turbo, the LW pulley made a more noticeable difference. When I went to the turbo motor and starting upping the boost, when swapped the pulley I really didn't notice the change.

So keep the above in mind when you are planning your upgrades. For the ej22t motor the best thing you can do is upgrade the turbo, add an intercooler, and raise the boost just below fuel cut. The small vf11 is a good turbo for quick spool up, but has poor efficiency at higher boost levels and will heat up the air more compared to a slightly larger turbo. You can run a TD05 with intercooler, up the boost slightly and still maintain the stock injectors and engine management. It would be advisable to get a wideband to check and make sure you're not running lean by raising the boost too much.

Just my two cents.

[MikeyMeyagi]

that stock intake manifold will by far outflow the crappy 22t sohc heads. if you want to make more power cheap, swap the heads out for the 25d ones.

[MikeyMeyagi]

and to answer your original question, No, the phase 2 sohc manifold will not bolt up to your heads.

[wtdash]

^Nor will the Phase 1 DOHC intake...just in case that was a question.

I saw your 'no cams' but I'd suggest looking into a Delta camshaft uprade. They have a 'street/torque' grind that doesn't require any EM changes and may give you the extra grunt.


Also, I ran the TB coolant bypass mod on my Legacy for 3 years in N. Idaho (down below 0°F on occcasion - avg Dec/Jan temps 20-35°F) and never had an issue.

GL,
Td

[Subierotic]

Thanks for all the advice.

Kimokalihi, thanks for the info. I will have to go search that post so I can figure out what I am doing.

Legacy777, I understand what you are saying about the hassle versus the gains. I was just thinking from my experiences with other engines that I might be able to shift the power band lower so I don't need to be into the boost so much (thinking about advancing camshafts too). I have been thinking about doing a phase 2 head swap if I end up realizing that it's my best ( $$ < Results ) option, but I don't think I will want to go DOHC, so I will have to do some more research on this topic.

MikeyMeyagi, I have heard that the stock 22t heads dont flow well. I will do more research, but can you tell me why you recommend the 25d heads, and what years/makes they are from. I did read that the phase 2 heads on the 2.2 had revised valve angles and such, but I am worried about having a bigger combustion chamber and loosing compression ratio.

wtdash, I talked to delta about a set of cams. I might go that route eventually. They told me that I could see 8-12% increase in power, and better mileage if I stay out of the boost. The problem with that is I have a hard time not boosting because of all the hills around here.

So, what I think I have learned is that I need to swap over to a set of heads from 99+, and then all SOHC intakes will swap with those type heads, and the same for DOHC intakes and heads? Too bad that it's not like my Jeep where I've got an 88 4.0 block, 76 4.2 crank, 94 head, and 2001 intake.

[wtdash]

Hi,
Not sure I'm clear what you're asking, but you can't swap intake manifolds between Phases.

The SOHC Phase 1 EJ22 '89-'98 IM's (turbo and NA use the same mounts) are different from the SOHC Phase 2 '99+ EJ22/EJ25 - I believe the Phase 2 SOHC EJ22 and EJ251/EJ253 Intakes use the same IM mounts, but not 100% sure.

Also, the newer stuff uses different wiring/sensors, etc. and will be more difficult to get to work w/your EJ22T.

So it's not just mechanical, but there are also electrical differences w/the newer stuff.

The DOHC Phase 1 EJ25D from '96-99 Legacy OB/GT/LSi, and '98 Impreza RS and '98 Forester are not compatible w/the newer stuff.

And note you'll have to modify the heads or find other water/oil sources for the turbo on any NA sourced heads. If you get an EJ20G head from overseas WRX/STi it'll be much more plug and play.

The easiest to use and find heads for the EJ22T are from the EJ25D and they do flow 20% more from what I've read.

This LINK will explain the EJ Series engines pretty well.

Td

[Falken-18c]

05-06 legacy na manifold has much longer intake plenum and longer and larger runners compared to any turbo manifold

[Legacy777]

What I would really suggest you do is identify your specific goals, before identifying the components. For example, "I would like to have an increase in power off boost, increased fuel mileage, better boost response, etc."

The other thing I'll just note is turbo engines are designed to run boost. Sure we all try to stay out of boost to increase mileage, etc, but it's difficult to do that because the engine was designed to use boost to provide the rated power across its operating window. I just mention this because sometimes folks try and treat turbo engines like non-turbo engines. While some of the ideas & principles are the same, the overall road map to the end results can vary.

From what I have found on my own personal experience, costs for upgrades/improvements can be substantially higher because turbo engines have more interconnecting pieces/components that are affected. You up the boost, you need more fuel which means larger injectors, more air means you may need to address engine management and sensor ranges, etc.

[Subierotic]

Thanks guys for your info. I have a lot of experience with turbo eclipse/talon stuff, and am quite familiar with which parts from what years gets you better performance with the DSM stuff. I'm on a learning curve with the subaru stuff now, and I'm trying to apply my ideas to this build.

Legacy777, I am indeed thinking about this build as if it were a N/A motor while off the boost, and that is because it has worked well for me in the past. Increased gas mileage is my main goal, but I know that when done right, increased power comes with it if you focus on efficiency. Anybody can add boost and fuel to make power, but that doesn't have to be the only recipe ( though it is needed for serious gains of course ).

I realize that the intake manifold is not the bottleneck in the power equation for this motor, but i'm sure that Subaru changed runner lengths and plenum volumes to broaden the power curve for those applications. I'm hoping to get a good understanding on what works with what, in hopes of achieving the type of power band that I am looking for.

[jefferson]

I just wanted to add that the subject of the ej22 heads not flowing well may be a much bantied about myth. I saw a link to I believe a nasioc thread about flow testing different Subaru heads. The ej22 head flowed well despite what everyone says. Someone here may know something about this. Could save you a bunch of time and money using the heads you have.

Jeff

[ghia nut]

Some stuff found on nasioc

IN MAX FLOW @ MAX LIFT
EJ25 SOHC: 240 CFM @ 0.375" Lift
EJ22T SOHC: 193 CFM @ 0.350" Lift
GM LS1: 231 CFM @ 0.500" Lift

EX MAX FLOW @ MAX LIFT
EJ25 SOHC: 182 CFM @ 0.310" Lift
EJ22T SOHC: 147 CFM @ 0.350" Lift
GM LS1: 193 CFM @ 0.500" Lift

Here's the link if you'd like to read it... some interesting thoughts in there along with typical nasioc "I know everything about Subaru" nonsense
http://forums.nasioc.com/forums/showthread.php?t=860335

Wish there was dyno graphs on delta cams
As far as gas mileage you could try the turbonator

What about an air filter that isn't the stock one.
Also you could try to find some ethanol free gas depending on where you are in the us.
Some people have reported a 1-2 MPG increase with a higher voltage coil.
I would also suggest basic maintenance and seafoaming the engine.

[Legacy777]

Legacy777, I am indeed thinking about this build as if it were a N/A motor while off the boost, and that is because it has worked well for me in the past. Increased gas mileage is my main goal, but I know that when done right, increased power comes with it if you focus on efficiency. Anybody can add boost and fuel to make power, but that doesn't have to be the only recipe ( though it is needed for serious gains of course ).

I realize that the intake manifold is not the bottleneck in the power equation for this motor, but i'm sure that Subaru changed runner lengths and plenum volumes to broaden the power curve for those applications. I'm hoping to get a good understanding on what works with what, in hopes of achieving the type of power band that I am looking for.

The ej22t has a relatively flat torque curve, especially at lower-to-mid rpms. This was my engine....pretty much stock.

http://www.main.experiencetherave.com/s ... gdyno1.jpg
http://www.main.experiencetherave.com/s ... gdyno2.jpg

It tapers off at the top due to the heads and stock turbo.

If increased gas mileage is your main goal what I would suggest is tuning, primarily I'd suggest looking at the Robtuned ECU's. The stock ECU tune is a very rich tune, the second dyno plot shows that. I'm sure we can thank that partly due to the US cars not having intercoolers. The Robtuned ECU's with an intercooler should improve mileage.

The other thing I'd suggest, get a slightly larger turbo....and the reason I suggest that is because the stock vf11 turbo is very small and spools very easily. So it's hard to stay out of boost for every day driving. Putting a larger turbo on, TD05 or comparible will still work fine for the stock engine, provide good boost response when asked upon, but shouldn't be spooling as frequently/easily as the vf11. As long as you run the stock boost, you really shouldn't notice any difference other than slower spool times, and maybe a little better power at high rpms due to the TD05 being able to move more air.

[kimokalihi]

My TD05 18g doesn't really spool until 3,400 rpm. Easy to stay out of boost with that turbo and my lower compression EJ20G hybrid engine.

[njdriver04]

Saw it was mentioned above, I am planning to put 04 wrx heads on my ej22t, if I use 04 wrx IM what else do I have to consider in terms of theIM

[Alphius]

Using PhaseII heads, your ECU will not be able to read the cam sensor and it will not run. Are you switching to a WRX ECU and harness on your engine as well?

[njdriver04]

yeah was planning on changing the ecu as well, if feasible splice the old wiring but will see. Going to go burn a bunch of hours absorbing knowledge.

[Dave_J]

Extrudehone is out of reach for most of us. One of the ways to smooth out the inside of a manifold is to put about 2 boxes of 0.177 BB's in, seal the ends and put it in a paint shaker for an hour. It will "Peen" all the bumps and ridges.

I'v been turbo'ing engines sence 1974 starting with a Plymouth 2.6 Colt. Following with RX3, Rotary Pickup and RX7 Mazdas. I too could build a 300 HP Mitzie 2.0L with stuff lying on my shelfs. And doing a NA 4.0L stroker 4.7 Jeep is also so easy to get 270 + HP. But these 91-94 Turbo 2.2 Suby's are a bear to pump up. Stupid engineering on the ECU. And there were not enough of these cars made for anyone to make a piggyback unit, unlike a WRX.

[njdriver04]

Everything you said Dave_J is spot on, I guess I should have clarified what I was saying, planning to use ej25d heads and intake manifold with a Robtune ecu.

[njdriver04]

Extrudehone is out of reach for most of us. One of the ways to smooth out the inside of a manifold is to put about 2 boxes of 0.177 BB's in, seal the ends and put it in a paint shaker for an hour. It will "Peen" all the bumps and ridges.

Might do this for fun, I know someone who owns a hardware store.

[James614]

Putting a larger turbo on, TD05 or comparible will still work fine for the stock engine, provide good boost response when asked upon, but shouldn't be spooling as frequently/easily as the vf11. As long as you run the stock boost, you really shouldn't notice any difference other than slower spool times, and maybe a little better power at high rpms due to the TD05 being able to move more air.

I've heard the exact opposite, that putting a TD05 on the stock engine will definitely max-out your injectors even at wastegate boost... It's the reason I'm running a TD04 right now as an interim before I get my robtune...