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Posted: Wed Feb 13, 2008 9:41 am
by dropdfocus
If you're looking for a set of EJ25D heads (2.5 DOHC), I have 2 sets available. I also have a pair of EJ25D intake manifolds too. I just cleaned out my buddy's garage & he's giving me everything to part out for him. By Wed/Thur I'll have pictures snapped of everything.

As for what has been said about the head swap & such, going with the EJ25D heads allows you to use the EJ20G/K/H intake manifold. Pure JDM goodness!

I did manage to pick up a JDM EJ20G intake manifold for my hybrid motor ($150 from a fool on NASIOC). Before I have everything installed, I plan on doing a mild port & polish on the intake. The only real problem with the JDM vs. USDM intake is that the original set up over in Japan was coil over plug design. So I need to make a braket to hold the coil pack where it would normally have mounts on the US model.

Posted: Wed Feb 13, 2008 4:47 pm
by Legacy777
I'd also suggest searching the archives and the board. There were some threads a long while ago where larry witherspoon was doing some research on what heads to use. I think there's a few other threads as well. Most give similar info, but may have some addition details.

Posted: Wed Feb 13, 2008 4:49 pm
by smh0101
Um... Whats exactly is a td04hl?

Posted: Tue Feb 19, 2008 2:58 am
by smh0101
PhyrraM wrote:Niether is 'better'.

Beyond simply saying SOHC or DOHC you need to where each one comes from.

SOHC is commonly refered to for both early BC/BF heads such as the stock Ej22t heads and also the heads on later (phase 2) Ej25s.

DOHC is really a bit of a cluster f**k. Ej20g, Ej20k, Ej20h are all DOHC. These are the most commonly discussed here. Ej205, Ej207, Ej255 and Ej257 are all newer (different ECU signals) and basically ignored on this forum. The early (phase 1) non-turbo USDM Ej25s also have DOHC heads.

Ej20g is BC/BF Legacy and early WRX (v1&2). Legacy heads have stub rockers while WRXs have cam-over-buckets. Both of these engines have the 'elbow' turbo inlet like our Ej22ts.

Ej20k is later WRX (v3&4) and is also cam-over-bucket. These engines have the under the manifold turbo inlet. There is also engines in these years Subaru labeled as Ej20g, but should be treated as Ej20ks because electrically and installation-wise that's what they are.

Ej20h is Legacy twin turbo. Electrically these are way out in left field from most other Subarus. But used just for the hardware, not the electrics, it's basically a Ej20k.

USDM phase 1 Ej25 heads are losely based on Ej20k heads. They only need existing bosses drilled and tapped for turbo oil and coolant lines.

The above heads are mostly interchangable because they all accept the same intake manifolds. The 'bolt in/plug-in" deal would be any of the above heads with an Ej20g intake manifold. For our cars the Ej20g intake manifold is prefered becasue it uses comapatable sensors and IAC. It is by all means not the only option.

The Phase 2 SOHC Ej25 head is a very good flowing head, but because it has no provisions for a turbo it seems mostly avoided.

The phase 1 SOHC head is what you have already got on a Ej22t.

Phase 1 and 2 refers to a mild redesign of the block by Subaru about '98. It appears mainly to adrress some problems that cropped up when Subaru 'factory stroked' the Ej20/22 series into the Ej25. Headgasket problems are the most notable. There are numerous improvements but the major ones were a change in the position of the thrust bearing on the crank, the size of the rod journals on Ej25s and structural improvements. As far as heads go there is little to concern yourself with as far as phase1 or 2.
So basically any jdm 2.0L DOHC setup is fine (minus twin-turbo) as long as I have the Legacy RS/V1/2 WRX ej20g intake manifold?

Posted: Tue Feb 19, 2008 3:10 am
by PhyrraM
Up to a point, yes. Once they started calling them Ej205/Ej207 they are no good. Those are the ones with the newer cam sensor timing.

If it's Ej20x (where 'x' is a letter) then you can slap on:

1) an EJ20g intake manifold.
2) an EJ22t engine/intake manifold harness on said manifold.
3) an Ej22t coil pack and plug wires.

Then plug her in and go.

Posted: Tue Feb 19, 2008 3:16 am
by smh0101
Sweet! Thanks...

Is there a difference between the different heads? I mean, which flows the best?

Posted: Tue Feb 19, 2008 4:43 am
by Arctic Assassian
the td04hl is a turbo that came on certain JDM wrx's and is capable of almost vf39 territory. Its got a bigger compressor housing than the td04l that came on the USDM wrx.

Posted: Tue Feb 19, 2008 4:47 am
by smh0101
So... how is its spool?

Posted: Tue Feb 19, 2008 4:16 pm
by BXSS

Posted: Tue Feb 19, 2008 5:31 pm
by smh0101
Wow... That was a long read! Bu very informative...

Posted: Mon Feb 25, 2008 5:10 am
by Matt Monson
smh0101 wrote:
PhyrraM wrote:Niether is 'better'.



Ej20h is Legacy twin turbo. Electrically these are way out in left field from most other Subarus. But used just for the hardware, not the electrics, it's basically a Ej20k.
So basically any jdm 2.0L DOHC setup is fine (minus twin-turbo) as long as I have the Legacy RS/V1/2 WRX ej20g intake manifold?
Two corrections here:

PhyrraM,
Even the twin turbo heads and manifold are fine. Just ask Douglas Vincent.

smh0101,
The Ej20H heads are actually HLA heads most similar to the Ej20G heads. The Ej20R heads, which were left off the list, are the last twin turbo heads and they are essentially the same as Ej20K heads.

Lastly, as for the comments about it potentially costing a fair bit more to make Ej22T heads flow for the desired power level, I don't know that I agree. The old Cobb flow charts that get passed around show the Ej22t heads to be about +/-15% less flow than Ej205 heads. A good port job will usually net you about +/-15% in flow. If you can get your ej22t heads ported and rebuilt for less than $500, then it's probably a cost effective approach worth considering.

Oh, one last thing. I have had several of those JDM td04's good little turbos. That's what's on my '91 SS that I sold at Christmas time. The car was putting out 240chp at 12psi on an Ej20G 2.0l engine. I don't know if Jeff has fiddled with it since he took the car home to Seattle, but I imagine that at around 1 Bar, that turbo could probably put out somewhere around 275-295chp depending on intercooling and ambient temps...

Posted: Mon Feb 25, 2008 5:22 am
by smh0101
Thanks Matt...

So how would the stock heads PnP be with a 2.35l stroker, a vf-12, and 440cc injectors be? With a Perfect Power, exhaust, ic etc. of course.

With say 16lbs of boost?

Any idea as to hp?

Posted: Mon Feb 25, 2008 5:27 am
by PhyrraM
Matt Monson wrote:
PhyrraM,
Even the twin turbo heads and manifold are fine. Just ask Douglas Vincent.
So the Ej20h/r TPS and the IAC is compatable with EJ20g/Ej22t ecus? If so, that is nice to know.

Posted: Mon Feb 25, 2008 5:35 pm
by BXSS
I have a JDM 90* TD04 on my EJ20G'd SS, I'm not sure if it is the same as the turbos listed in the above link (I saw a pic with a straight inlet) but it works way better than I thought it would.

I thought I was going to swap a TD05-16G on right away, but I was so surprised that I have not swapped a 16g onto my car yet.

I want to track the car as is with the TD04 to see what it could do.

Posted: Mon Feb 25, 2008 5:42 pm
by dropdfocus
You'd have a bit of noticeable lag with the 16g vs. the quicker spooling TD04. Obviously the peaks out where the 16g keeps making power for the motor.

Of course if you have a 16g you don't "want" to use, I'd be glad to "use" it for ya Carlos. :mrgreen:

Posted: Mon Feb 25, 2008 8:01 pm
by BXSS
Yeah, I figured that the 16g would have some more lag.
I like the response of the TD04, but would like some more top-end.

I'm going to put a 16G on eventually, but I have to see what the TD04 can do.

As for 16Gs I now have 4, 3 Good 16s + 1 POS parts donor.
1 is pending sale & I'm going to keep the 2 other good ones (1 for use + 1 spare).
The parts turbo has a bent compressor blade + shaftplay like a mo-fo so its more or less a paperweight.

My friend/fabricator wants me to skip the 16G all-together & go straight to my t3/t4e - he says the 16g looks like a cookie (he runs a GT45R) & is a waste of time.

Posted: Mon Feb 25, 2008 8:05 pm
by Legacy777
I don't know about all 16G's, but I wouldn't say the ported 16G I have on my car with associated mods spools that much slower then stock.

Posted: Mon Feb 25, 2008 8:09 pm
by BXSS
Funny, the one pending sale has a very nice up-pipe match port (took about 30-45 minutes with a new carbide porting bit).
When I put one on the SS it will definatly get ported too.

Posted: Mon Feb 25, 2008 8:10 pm
by Legacy777
I had the turbine section ported, and the 90 deg inlet section ported.

The compressor outlet for the most part should be alright, at least that's what I've been told.

Posted: Sun Mar 09, 2008 7:53 am
by chochocho
bxss, the turbo looks good. i am looking to get some porting done by a shop here in cali.

i hope to have the turbo installed in a few weeks. thanks.

Posted: Sat May 10, 2008 5:12 am
by smh0101
Can you use a 20g intake manifold with the 2.5l dohc heads? Or do you need the ej25d intake mani?

Can you use the 22t electrics with the 25d manifold?

Posted: Sat May 10, 2008 5:23 am
by PhyrraM
Yes, you can use the EJ20g intake manifold with EJ25 DOHC heads.

I don't know if the IAC or the TPS on the EJ25D is compatable with EJ22t electrics. Also, EJ25D has EGR, the EJ22t does not.

Posted: Sat May 10, 2008 5:29 am
by smh0101
Um... EGR?

But if I used a 20g manifold everything would be fine?

Posted: Sat May 10, 2008 6:16 am
by asc_up
EGR=Exhaust Gas Recirculation.

Posted: Sat May 10, 2008 6:19 am
by dropdfocus
You make a block off for it. I'll be doing that for my setup (EJ20G intake, EJ25D heads, & EJ22T block). Since it's not required on the older cars, it can be blocked.