EJ20R from OBDI to OBDII?

[Dead91silvia]

Hey guys, I have a spare EJ20R I picked up a while back (thanks to slavik.86) and I had an idea.

I looked and it seems to have the came crank and cam sensors as the EJ25D in my BD. What I would like to know is if I can convert my EJ20R to OBDII and a single turbo. I dont have every part for a TT setup, and was only really keeping this motor as a spare, but I have a feeling my EJ25D with 285K wont last long with boost.

So what do you guys think? What parts would I need to do this? Would most of the EJ25 parts swap over?

[slaytalera]

Theres a few ways you MIGHT be able to do this, but as ive never had a 20r i cant say for sure. IF 20G heads fit the block, you can use the 25D IM, harness and sensors and itll be plug and play (the only thing im not sure about is the crank sensor, i know the 20g and 25d crank sensors are the same, i just dont know about the K/R) and then use a jumper harness and use a JDM ECU, or use a PP6 with the injector add on or greddy emanage for "mapping" a stock 25D ecu

[slaytalera]

actually, you specified OBDII, so cancel the part about the JDM ECU

[Garrison]

Why not just freshen up the block (new rings, seals, etc) and use the heads from your ej25? Single turbo, no need to swap manifolds and daily reliability?

[Dead91silvia]

This motor needs more then rings... The 20R I have should be all good to go, as far as I know. I have no want to split a block in other words.

[slaytalera]

The only other way is to see if WRX heads work on it, then redo the wiring harness and use a USDM WRX ECU with it as well

[Garrison]

Found this while trolling around:
http://www.b4et.com/docs/cr_matrix.pdf

[Reuben]

Why not just freshen up the block (new rings, seals, etc) and use the heads from your ej25? Single turbo, no need to swap manifolds and daily reliability?

Because EJ25D heads are crap, and mushroom combustion chambers inefficient. 20R heads on the other hand are among subaru's best, they deliver your 206kw with a bite, the camshafts are also among the most aggressive subaru ever made too. 20R heads are put simply, a fuck load of fun, and a kick in the pants compared to any other STi head (Note 20R heads are the same as V3/4 STi 20K heads)(specifically, a BG5B 20R = V3 STi, a BG5C 20R = V4 STi).

Thankfully the lego effect applies to blocks as well, you can bolt on required OBD-II gear if you want. But why would you, import a V3 STi ECU (6S), and have some fun.

I've converted a phase-III longblock to run on my dads phase-II BH twin turbo, I had to change the timing cam pulley, and the crank sprocket, and just used his phase-II intake manifold. I don't see why you wouldn't be able to do the same with a 20R block. You can make spacers for the maniold to convert it to the phase-II+ bolt pattern, and just run a phase-II manifold, then if the crank sprocket and timing pulley are wrong, swap those, presto, 20R running OBD-II. I would recommend a tune to make the most of the camshafts though, as any turbo OBD-II turbo ECU is going to be tuned totally different.

Essentially the V3/4 STi's and their 20K (same as 20R) made their 206kw by throwing all of the fuel at it, and running a fucking huge turbo (VF22), and aggressive cams. every model after the V3 STi ran with a smaller turbo and less aggressive cams, and achieved the 206kw by other means. That is why the 20R/20K heads are so much fun to drive, they are pretty fucking rough and achieve their power by hitting it with a stick, rather than asking for it politely like subsequent models. The exception is the V7 STi, they were the first to run AVCS, and subaru used this new found power for evil, rather than for good. Again, V7's have bloody aggressive cams (I might add we're talking relative here, comparing to other stock subie cams), and they weren't twin scroll, so they used a turbo of very comparable size to the VF22, the VF30. Subsequent models changed the cams to be better on gas again and achieved their 206kw by other means, like twin scroll turbo's, and subtle tweaks here and there etc.

The DOWNSIDE to the 20R... The heads are amazing, the blocks are shit. The block is nothing special, and the 20R got cast pistons, not forged, so the pistons are weak, the bottom end is notorious for running big ends, and it's from the fully open deck era. A thinking man would chuck his 20R heads only an old closed deck 2.2 block, with forged low compression pistons, take a bit off the cams to make them even more fun, port and polish the heads, 22psi on some big injectors and custom ECU, and bam, little monster of a motor. You can even chuck em on a 2.5 if you want, smaller heads than block is fine, as long as there's no mushroom, you're all good. But why would you if you can make the 22 rev out to 8000rpm :D

And lastly, those in the know will be saying "wait, but 20R and 20K heads aren't the same!" Only half right, the head is the same, but 20R runs shim over bucket, 20K runs shim under. this does not affect their abilities though, the 20R still runs the same camshafts as the equiv year STi, but factory redline is only 7500rpm, not 8000. Regardless, I've redline my 20R heads to 8k for 5 years now and they are juuuusssssstttttt finnnneeee.... :D

i'm also going to run a foot note here, everything i've said above is relative, comparing the little nuances of each (jdm) STi to each other, and copying some things from here and there. I've driven many STis, V9, V6, V4, V3, and V2 RA, they all fucking haul, and are all an immense amount of fun. any advantage the V3 has, can instantly be overshaddowed with a single mod to any other model. Chuck something bigger than a VF22 onto a version 6, and suddenly the addictive kick in the pants a V3 has seems like something a hairdryer could pull off! And later model gear can take much much better to modding than the early stuff. If one is playing the lego game, not the aftermarket game, then V3/4 STi (and 20R) is a hell of a lot of fun, and bloody good bang for buck, but as I said, everything is relative

[Dead91silvia]

I gave up on reading the tinny print... haha...

Good info though Reuben! I'm now planing to go with a Stand Alone system as of now. This way all I really need to worry about is converting it to a single turbo. The ECU for the EJ25 in my car right now is not tune-able.

[EJ22D]

Why not just freshen up the block (new rings, seals, etc) and use the heads from your ej25? Single turbo, no need to swap manifolds and daily reliability?

Because EJ25D heads are crap, and mushroom combustion chambers inefficient. 20R heads on the other hand are among subaru's best, they deliver your 206kw with a bite, the camshafts are also among the most aggressive subaru ever made too. 20R heads are put simply, a fudge load of fun, and a kick in the pants compared to any other STi head (Note 20R heads are the same as V3/4 STi 20K heads)(specifically, a BG5B 20R = V3 STi, a BG5C 20R = V4 STi).

Thankfully the lego effect applies to blocks as well, you can bolt on required OBD-II gear if you want. But why would you, import a V3 STi ECU (6S), and have some fun.

I've converted a phase-III longblock to run on my dads phase-II BH twin turbo, I had to change the timing cam pulley, and the crank sprocket, and just used his phase-II intake manifold. I don't see why you wouldn't be able to do the same with a 20R block. You can make spacers for the maniold to convert it to the phase-II+ bolt pattern, and just run a phase-II manifold, then if the crank sprocket and timing pulley are wrong, swap those, presto, 20R running OBD-II. I would recommend a tune to make the most of the camshafts though, as any turbo OBD-II turbo ECU is going to be tuned totally different.

Essentially the V3/4 STi's and their 20K (same as 20R) made their 206kw by throwing all of the fuel at it, and running a fucking huge turbo (VF22), and aggressive cams. every model after the V3 STi ran with a smaller turbo and less aggressive cams, and achieved the 206kw by other means. That is why the 20R/20K heads are so much fun to drive, they are pretty fucking rough and achieve their power by hitting it with a stick, rather than asking for it politely like subsequent models. The exception is the V7 STi, they were the first to run AVCS, and subaru used this new found power for evil, rather than for good. Again, V7's have bloody aggressive cams (I might add we're talking relative here, comparing to other stock subie cams), and they weren't twin scroll, so they used a turbo of very comparable size to the VF22, the VF30. Subsequent models changed the cams to be better on gas again and achieved their 206kw by other means, like twin scroll turbo's, and subtle tweaks here and there etc.

The DOWNSIDE to the 20R... The heads are amazing, the blocks are shit. The block is nothing special, and the 20R got cast pistons, not forged, so the pistons are weak, the bottom end is notorious for running big ends, and it's from the fully open deck era. A thinking man would chuck his 20R heads only an old closed deck 2.2 block, with forged low compression pistons, take a bit off the cams to make them even more fun, port and polish the heads, 22psi on some big injectors and custom ECU, and bam, little monster of a motor. You can even chuck em on a 2.5 if you want, smaller heads than block is fine, as long as there's no mushroom, you're all good. But why would you if you can make the 22 rev out to 8000rpm :D

And lastly, those in the know will be saying "wait, but 20R and 20K heads aren't the same!" Only half right, the head is the same, but 20R runs shim over bucket, 20K runs shim under. this does not affect their abilities though, the 20R still runs the same camshafts as the equiv year STi, but factory redline is only 7500rpm, not 8000. Regardless, I've redline my 20R heads to 8k for 5 years now and they are juuuusssssstttttt finnnneeee.... :D

i'm also going to run a foot note here, everything i've said above is relative, comparing the little nuances of each (jdm) STi to each other, and copying some things from here and there. I've driven many STis, V9, V6, V4, V3, and V2 RA, they all fucking haul, and are all an immense amount of fun. any advantage the V3 has, can instantly be overshaddowed with a single mod to any other model. Chuck something bigger than a VF22 onto a version 6, and suddenly the addictive kick in the pants a V3 has seems like something a hairdryer could pull off! And later model gear can take much much better to modding than the early stuff. If one is playing the lego game, not the aftermarket game, then V3/4 STi (and 20R) is a hell of a lot of fun, and bloody good bang for buck, but as I said, everything is relative

Reuben, you have confirmed exactly the rest of the information about what I needed to know about 20R heads on a 2.2 block. I can envision them being even more efficient on a 22E or a 222 block so long as the pistons & rods are replaced.

However, I would not use ANY 25D block unless it is a 99+ (Phase 2) because the rods are smaller in dimension & simply cannot handle the rpm OR the power the 20R heads would try to spin them up to produce.

Even if you DID boost a Phase 1 25D, you'd better have a damn good tunable ECU & plenty of fuel to feed it with. I am still trying to figure out if I want to keep the twin turbo setup when I order my 20R to combine with my current 22E block (so far as I know, it would be the first twin turbo EJ22) or if I just want to put a single turbo setup on it & keep rolling on.

[Reuben]

You essentially can't tune twin turbo, no aftermarket ECU can drive it either, so if you want to start doing displacement and injector mods, gotta roll with single turbo. There are exceptions, but generally speaking you can't do much with TT.

[86bratman]

Rueben, which of the two ej25d heads do you have the extreme hatred of? We had two here, 96 only large chamber hla in bucket style similar to earlier ej20g heads, and 97-99 small clover chambers with shim over bucket.

[Dead91silvia]

Rueben, which of the two ej25d heads do you have the extreme hatred of? We had two here, 96 only large chamber hla in bucket style similar to earlier ej20g heads, and 97-99 small clover chambers with shim over bucket.

The later style are the problem ones. AKA, smooth valve cover heads. They are however the most common. The early one's (96-early '97) are useful for turbo builds, so I'm told.

So I'm assuming the smooth valve cover EJ25D heads.

[86bratman]

I know they like to blow gaskets, but the smooth cover'd, clover combustion chamber heads are the ones that everyone seems to seek out for ej22 turbo builds. Just trying to clear up a little confusion on my end lol.

[Reuben]

Rueben, which of the two ej25d heads do you have the extreme hatred of? We had two here, 96 only large chamber hla in bucket style similar to earlier ej20g heads, and 97-99 small clover chambers with shim over bucket.

Heads are fine, you just cant use them on lower displacement blocks unless you're (American and disregarding logic apparently)(mushroom shaped compustion chamber no goodsies). Do note that they do flow less that turbo heads too, they are therefore really only any good for use as designed, 2.5L N/A's (there was discussion on nasioc many moons ago with some twat asserting that 25D heads were the same casting as turbo heads... In the end I had to shoot the argument down by going and taking picutres of the cast markings on my 20R heads, where were totally different (same year)). Other than that, for an N/A build, great!
And on a second note, I guess that I forget that that's the best you guys have for that year range... In NZ we'd never even consider using a 25D head, cause we have turbo heads of the same year just kicking round in everyones garage pretty much. Without access to turbo heads from that era, then the 25D really is next best, they are the best of the N/A heads really.

It's the blocks I hate, bore and stroke are both far too large for the EJ to handle, my hatred is the unreliability giving subaru a bad name, and the low rev limit... I've got 8250 rpm to play with in the GTB, and let me tell you, I bloody use it. Show me an EJ25 that can rev out to 8000rpm, reliably, and affordably, and I'll be sold.

The 2.2 however I love, because the stroke is the same and so redline isn't really affected I'm told, and the bore isn't so huge that they pop headgaskets every second tuesday. Now, if 25D heads bolt to 22's without getting the mushroom chamber, then fucking ACE, that's an n/a build I'd love to see.

[86bratman]

I'll see if I can find a picture I took a while back of the later style ej25d head with an ej22 gasket sitting on it. That particular head style is suited to the smaller bore, unlike the 96 model.

I also need to get around to posting pictures of the build I've been working on. Ej22 with eg33 pistons and 97-99 ej25d heads.

[Reuben]

Well that is bloody cool, in that case, awesome heads to be using! I'd rate them over the EJ22 turbo heads for example :P

[86bratman]

I would too, ej22 heads in general suck, they just made them worse, 1mm worse to be exact, for the turbo engine lol.
Anyways finally got the pics uploaded.
https://sl-i.net/FORUM/images/imported/2013/10/IMAG1128_zps2f99b9a7-1.jpg

https://sl-i.net/FORUM/images/imported/2013/10/IMAG1127_zpse4198050-1.jpg

https://sl-i.net/FORUM/images/imported/2013/10/IMAG1129_zps53de240a-1.jpg

As you can see there is actually plenty of space between the compression ring of the head gasket and the chamber on the head. These are the 97-99 ej25d heads, the 96s you can literally take an ej22 piston skirt side down and fully insert it in the chamber.

[EJ22D]

Show me an EJ25 that can rev out to 8000rpm, reliably, and affordably, and I'll be sold.

I wouldn't be able to, so you just saved your money. As far as I know, there IS no N/A 25D here that can rev at it's own redline here reliably. Even the 99 25Ds & their Phase 2 blocks can't do it. This is that one time where Subaru was wrong in catering to the people's need for TQ over reliability.


The 2.2 however I love, because the stroke is the same and so redline isn't really affected I'm told, and the bore isn't so huge that they pop headgaskets every second tuesday. Now, if 25D heads bolt to 22's without getting the mushroom chamber, then fucking ACE, that's an n/a build I'd love to see.

viewtopic.php?f=6&t=26149 (http://www.sl-i.net/FORUM/viewtopic.php?f=6&t=26149)

Welcome.
There is no mushroom chamber present & the chambers to the 25D are actually smaller than the 22E/T/2 bore, which makes for a pretty good N/A or turbo setup, depending on what gasket or block is used to determine end compression ratio. Using a 222 block will yield the highest, due to it's completely flat pistons. I use a 22E block in my hybrid.

As for the twin turbo setup, is there truly no way to copy the map on the twin turbo ECUs so that we can have a base on which to progress on an aftermarket ecu? If that could be done, then I would imagine that using an EJ22 block would not be so much of an issue.

[Garrison]

Thank you 86bratman, and EJ22D for posting up some very insightful info.

EJ22D,
By the time you spent the money for tuning a twin turbo setup and eliminating as many of the headaches as possible, you could have grabbed a GTX series (variable vein) turbo and had a similar output with much less head ache.
Fwiw, I plan on using your setup with a td05-18g w/8cm hotside and a phase 2 (2.2) block w/ EJ205-ish pistons.
That or a phase 2 (2.5) block with EJ255 pistons/Sti rods :twisted:

[86bratman]

Don't let Rueben see this... lol.

I've considered building the latter setup there, ej251 with sti rods and pistons under 96 ej25d heads. Keeps the compression ratio at 8.3:1 with an sti head gasket. Of the heads I have availible to me, the 96's are the closest match to ej257 combustion chambers. And don't have the avcs and tumble generator crap to deal with.

[Garrison]

Seeing as the ej251 is waaaay easier to find, I think that will be the route I undertake, albeit with the 98' ej25d heads. Any recommendations on cams? If I'm going to do it, I'll be porting and polishing as well as drilling and tapping them for oil/coolant feed.

[EJ22D]

Hey guys, I have a spare EJ20R I picked up a while back (thanks to slavik.86) and I had an idea.

I looked and it seems to have the came crank and cam sensors as the EJ25D in my BD. What I would like to know is if I can convert my EJ20R to OBDII and a single turbo. I dont have every part for a TT setup, and was only really keeping this motor as a spare, but I have a feeling my EJ25D with 285K wont last long with boost.

So what do you guys think? What parts would I need to do this? Would most of the EJ25 parts swap over?

To answer your question directly, it can be done, since all of the ignition timing is the same in ALL EJ engines of Phase 1. All you would need is a piggyback, 25D wiring harness, & 25D ECU.

I am in the process of ordering a 20R just so I can gut it for it's heads & intake manifold, since I have no idea how to run the twins in parallel.

My recipe will be the following, 20R heads, 22E block, 205 turbo/exhaust manifold, 20K or 20G intake manifold, 25D wiring harness, 20R injectors, Walbro fuel pump, 25D ECU, & piggyback ECU to control the timing.