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Discussion Starter · #1 ·
Hey, I’m wanting to to install a catch can on my Jdm 97’ gc8 wrx sti. It has the ej20k, I was just wondering how is the best way to hook it up. Ive seen an old thread where it was installed off the air intake vacuum
line and off the map sensor intake manifold. There is currently a metal/rubber vacuum that runs between the air intake and intake manifold. Installing it this way deletes that I believe, I’ll post a picture for reference
Motor vehicle Vehicle Hood Automotive design Car
 

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i would like to help you, but a couple things.
1. the engine pictured appears to be a version 5 STi EJ207, not a EJ20k
2. the line you have circled is the idle air control valve.
3. Whis is there are 2 idle air control valves in the picture?
4. how many catch cans do you have? i recommend having 2
5. You should consider getting an oil/air seperator instead
 

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Discussion Starter · #3 ·
i would like to help you, but a couple things.
1. the engine pictured appears to be a version 5 STi EJ207, not a EJ20k
2. the line you have circled is the idle air control valve.
3. Whis is there are 2 idle air control valves in the picture?
4. how many catch cans do you have? i recommend having 2
5. You should consider getting an oil/air seperator instead
i would like to help you, but a couple things.
1. the engine pictured appears to be a version 5 STi EJ207, not a EJ20k
2. the line you have circled is the idle air control valve.
3. Whis is there are 2 idle air control valves in the picture?
4. how many catch cans do you have? i recommend having 2
5. You should consider getting an oil/air seperator instead
Really?? I always thought it was an ej20k how can you tell the difference? Must’ve been swapped but I wasn’t aware of that.

yes I realize what I circled is the idle air control valve, I just seen someone hook up a catch can and deleting that so I wasn’t sure if that was how it should be done or not

I could get an air/oil separator or two instead of a catch can i was just wondering what would be the best way to hook them up
 

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The intake manifolds are different. The most immediate and obvious give away is the coilpack. The 20K has a coil pack directly in the middle of the manifold the version 5 was the only one that had it off to oneside. The ver.6 went to coil on plug. The thing that is interesting is that the K and 7 use different intake manifold bolt patterns, meaning they wont bolt up to the heads they weren't ment to. Which leads me to believe one of two things has occured. either A) it has a EJ20K swap and someone tried to bolt a 7 in place of the K and had to do janky things to get it to run. or B) it has a EJ207 and someone used some EJ20K parts to try to make it run.
Anyway
The spererators should have 3 ports/fittings.
For the first seperator, there is a fitting with hoses that comes off the top of each valve cover. those hoses should connect to the Oil/air spererator then hook up to the fitting under the manifold.

As for the other one, there is a fitting that comes off the top of the block right by bellhousing, near the turbo. that pipe spits into two. one goes into a fitting under the manifold bright below the throttle body ( the PCV). the other goes to the turbo inlet. eliminate the "y" pipe and send it to the seperator. then hook the other two fittings on the seperator to the locations that they connected to before (pcv fitting and the turbo inlet.)
 

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Discussion Starter · #5 ·
The intake manifolds are different. The most immediate and obvious give away is the coilpack. The 20K has a coil pack directly in the middle of the manifold the version 5 was the only one that had it off to oneside. The ver.6 went to coil on plug. The thing that is interesting is that the K and 7 use different intake manifold bolt patterns, meaning they wont bolt up to the heads they weren't ment to. Which leads me to believe one of two things has occured. either A) it has a EJ20K swap and someone tried to bolt a 7 in place of the K and had to do janky things to get it to run. or B) it has a EJ207 and someone used some EJ20K parts to try to make it run.
Anyway
The spererators should have 3 ports/fittings.
For the first seperator, there is a fitting with hoses that comes off the top of each valve cover. those hoses should connect to the Oil/air spererator then hook up to the fitting under the manifold.

As for the other one, there is a fitting that comes off the top of the block right by bellhousing, near the turbo. that pipe spits into two. one goes into a fitting under the manifold bright below the throttle body ( the PCV). the other goes to the turbo inlet. eliminate the "y" pipe and send it to the seperator. then hook the other two fittings on the seperator to the locations that they connected to before (pcv fitting and the turbo inlet.)
The intake manifolds are different. The most immediate and obvious give away is the coilpack. The 20K has a coil pack directly in the middle of the manifold the version 5 was the only one that had it off to oneside. The ver.6 went to coil on plug. The thing that is interesting is that the K and 7 use different intake manifold bolt patterns, meaning they wont bolt up to the heads they weren't ment to. Which leads me to believe one of two things has occured. either A) it has a EJ20K swap and someone tried to bolt a 7 in place of the K and had to do janky things to get it to run. or B) it has a EJ207 and someone used some EJ20K parts to try to make it run.
Anyway
The spererators should have 3 ports/fittings.
For the first seperator, there is a fitting with hoses that comes off the top of each valve cover. those hoses should connect to the Oil/air spererator then hook up to the fitting under the manifold.

As for the other one, there is a fitting that comes off the top of the block right by bellhousing, near the turbo. that pipe spits into two. one goes into a fitting under the manifold bright below the throttle body ( the PCV). the other goes to the turbo inlet. eliminate the "y" pipe and send it to the seperator. then hook the other two fittings on the seperator to the locations that they connected to before (pcv fitting and the turbo inlet.)
Thank you so much for all the information! That’ll help me out very much. Appreciate it!
 

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Hey, I’m wanting to to install a catch can on my Jdm 97’ gc8 wrx sti. It has the ej20k, I was just wondering how is the best way to hook it up. Ive seen an old thread where it was installed off the air intake vacuum
line and off the map sensor intake manifold. There is currently a metal/rubber vacuum that runs between the air intake and intake manifold. Installing it this way deletes that I believe, I’ll post a picture for reference View attachment 88630
Sorry this is off topic but can you tell me which radiator tie downs those are?
 

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