Ej20 twin turbo conversion to EJ20 single turbo

ej22t · Post by **ej22t** » Wed Aug 02, 2006 5:08 am

Hi all... on the beginning of July, I went to a track day and blown my EJ20G 1 gen Legacy turbo engine and now I have a good and cheap choice of the engine selection.... a EJ20H twin turbo to make it single turbo.
A friend of mine who has a twin turbo Legacy engine in the shop for long time ago and he told me he could sell it to me cheap but all I have to do is to find all the information to make sure this engine are suitable for the BC5(91-94) turbo car.

I am new to this turbo engine and not too much knowledge about the conversion, so I would like to ask you guys/gals for help....

Read some topic in i-club and know someone already did this swap and told that this engine is far better then the WRX EJ20G engine, is it right?

As the member in i-club told me to just swap the intake and exhaust manifold to make it single turbo setting, is it that sample?

Hows those wiring things compair to the old ej22t wiring? Can I use the EJ22t ECU to make it run?

What will be the highest boost can this engine could handle?

Will the crossmember could fit this engine?

Thanks for all input and I will try to take as much photos during the conversion....

Ben

Matt Monson · Post by **Matt Monson** » Wed Aug 02, 2006 4:13 pm

ej22t wrote: As the member in i-club told me to just swap the intake and exhaust manifold to make it single turbo setting, is it that sample?
Ben

This is the proper information. Since you have already been running an EJ20G, there will be no wiring, and you will run it just like you have been. Just pull the intake manifold complete with intake manifold wiring and all plumbing and just bolt it up to the EJ20H longblock. And the same with the exhaust. Using your current exhaust will do the single turbo conversion for you.

Calling the Ej20H a better engine is really subjective. It's at least an equal engine and like your old engine can handle plenty of boost and make good power...

Binford · Post by **Binford** » Wed Aug 02, 2006 4:39 pm

Can I ask what the differences are between the ej20G and ej20H? Different internals, CR? Just curious.

Matt Monson · Post by **Matt Monson** » Wed Aug 02, 2006 8:37 pm

IIRC, the EJ20H is 8.8:1 instead of 8.5:1. Also, like the 94-96 WRX, it uses HLA's under buckets instead of the HLA's with little stub rockers that were used on the early Liberty?Legacy Ej20g's. I should point out that 94-96 WRX engines are also tagged as Ej20G's, but had the same rocker changes as the EJ20H's.

Lastly, Ej20H's are open deck, while 89-94 Ej20G's are closed deck. Only STi Ej20G's from 94-96 WRX's were closed deck. And even then it's really hit and miss. There's a lot of arguement about when the actual change date was, and even guy who have purchased '95 STI front clips have gotten their engines apart to find an open deck engine in there...

ej22t · Post by **ej22t** » Wed Aug 02, 2006 9:17 pm

Thanks Matt,
So I could use the EJ22T fuel injector into this EJ20H engine and run everything as the stock one, am I right?

Also since the 8.8:1 comparssion ratio, what should I set on the AVC-R? What will be the top limit on the turbo boost?
Does the VF11 turbo have enough boost to make the car runs more power or I should change to other turbo to make the car has more power output?

Thanks for answers those questions.

Wish me luck for the project on the 3rd engine swap to my BC5 Legacy turbo.

Ben

tzedek · Post by **tzedek** » Wed Aug 02, 2006 9:52 pm

you will have to block off the oil and coolant passages on drivers side head, as you dont have a turbo on that side. It should be pretty simple though, those are supposed to be pretty good flowing heads.

Matt Monson · Post by **Matt Monson** » Wed Aug 02, 2006 9:59 pm

Wait a minute. I just got confused. Have you been running an Ej220G on Ej22T injectors? Give me details of your Ej20G installation...

ej22t · Post by **ej22t** » Wed Aug 02, 2006 10:36 pm

Yep, I got to use the old ej22t (stock engine) fuel injector and fuel rail for the EJ20G engine. Since the injector connector is different and we test that may cost some of no signal on the injector so we put back the ej22t pink injector to the engine, and it do runs really well and no bad feeling on all range.

Also I did put a Walbor high output fuel pump to maxmize the flow.

Ver. 2 intercooler and K&N air filter.

AVC-R with high 16psi output, low 13psi output setting.

one-way bleed type FCD

3" turbo back exhaust

One of the engine problem is the coolent temp. sensor has problem eventhough I put a new one on and it still not working so I bypass with a resistor to trick it like running cool so the engine was running rich even the engine is hot.

Ben

ej22t · Post by **ej22t** » Fri Aug 04, 2006 1:53 pm

Does anyone know the boost limit on this EJ20H engine since the compress ratio is higher then the EJ22T.
Also, any method that I could increase the low end troque since I think troque is more useable then Hp

Thanks for reply!

Ben

Matt Monson · Post by **Matt Monson** » Fri Aug 04, 2006 5:26 pm

The higher compression will aid your low end torque. The boost limit on that engine is still in the high teens. It's pretty bullet proof. But currently the weak link in your system is your injectors. I would hazard to guess that not enough fuel was part of your original failure. I would address the injector issue when you install the new engine if you are going to continue to run the kind of boost you have been running...

ej22t · Post by **ej22t** » Sat Aug 05, 2006 1:00 am

Thanks Matt, Now into another questions:
What injector should I use??
Should I put the EJ20H injector with the EJ20G intake manifold and the EJ20G fuel rail? BTW, will it fits????
How about the Ej20G gray injector?

Please help, I am almost start this engine and hope could done before Sept.

THanks for all input!

Ben

napphappy · Post by **napphappy** » Sat Aug 05, 2006 1:46 am

G and H injectors are probably identical. And yes they will be a great choice. I think, those injectors are good to about 300cHP MAX.

You should really look into getting an EJ20g ECU, if you dont already.

ej22t · Post by **ej22t** » Sat Aug 05, 2006 7:25 am

Thanks Napphappy, I did have a EJ20G ecu before, but I don't have the wiring harness when I running the EJ20G engine so I sold it to someone who make the rally car and now I am still running the EJ22T ECU as well with AVC-R for boost control.

I may keep in low budget to run this engine thats why I can't afford a stand along ECU, but do you think the EJ22T ECU will do the work??

Ben

napphappy · Post by **napphappy** » Sat Aug 05, 2006 7:57 am

Yeah it will work fine.

ej22t · Post by **ej22t** » Sun Aug 06, 2006 5:49 am

How about injector?
Does anyone knows the EJ20H injector could put in EJ20G intake manifold?

Thanks for reply!!

Ben

bepa · Post by **bepa** » Sun Aug 06, 2006 6:14 am

[quote="Matt Monson"]IIRC, the EJ20H is 8.8:1 instead of 8.5:1. Also, like the 94-96 WRX, it uses HLA's under buckets instead of the HLA's with little stub rockers that were used on the early Liberty?Legacy Ej20g's. I should point out that 94-96 WRX engines are also tagged as Ej20G's, but had the same rocker changes as the EJ20H's.

Lastly, Ej20H's are open deck, while 89-94 Ej20G's are closed deck. Only STi Ej20G's from 94-96 WRX's were closed deck. And even then it's really hit and miss. There's a lot of arguement about when the actual change date was, and even guy who have purchased '95 STI front clips have gotten their engines apart to find an open deck engine in there...[/quote]

what's the difference between open/close deck engines? thanks!

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Ej20 twin turbo conversion to EJ20 single turbo

Ej20 twin turbo conversion to EJ20 single turbo

Re: Ej20 twin turbo conversion to EJ20 single turbo

differences open/close deck