legacycentral bbs

So as I'm starting to tie things together I'm finding my memory is failing me a little and I've got a couple questions about routing of various lines. I think they're pretty basic but I just want to double check. I'd like this thread to become a good resource as well.

Quick refresh on my setup - EJ22T short block, EJ20H heads. WRX coolant tank.

Coolant questions -

The turbo has two coolant lines. One line goes to a hard line coming off the back side of the head. The second line goes to the coolant tank?

The water pump has two hard lines coming off of it and wrapping up to the top side of the block. One line goes to the heater core. One line goes to the coolant tank? It doesn't matter which line goes to which correct? One of them has the little nipple for the IAC so I'm using it for the heater core.


Vacuum questions -

Most of these revolve around the purge valves and charcoal canister. I have three lines coming off my intake manifold.

One line goes to the purge valve #1 (the one located on the intake manifold, has the blue connector). The outlet goes to the charcoal canistor.

One line goes to the brown valve - it has the atmospheric vent, and is located beside the MAP sensor. Here's a question - which line on this guy goes to the intake manifold and which goes to the MAP sensor?

One line goes to my FPR, boost gauge, and boost controller.


Charcoal Canistor questions -

There are three lines coming off the charcoal canistor. One line goes to purge valve #1. One line goes to the fuel tank. These two are easy enough.

The third line goes to purge valve #2 and has a check valve/tee in it. The canistor says this goes to purge valve #2. Where is purge valve #2? The valve/tee has a 1/8" line and a 1/4" line. The 1/4" line goes to the intake, pre-turbo correct? I assume the 1/8" line goes to purge valve #2.


I believe that's all my questions and thank you in advance. I know these are items I can look up, and I have, but many of the diagrams aren't the clearest and I just want to be sure I'm setting things up correctly.

Found the answers to the vacuum lines. Many thanks to Vikash and to the BBS archive - http://web.archive.org/web/200609161235 ... ~v/vacuum/.

Looks like the little check valve/tee is actually the auxilarly purge valve. That explains why I haven't been able to find any extra wiring connectors for it.

Your coolant line routing sounds fine.

Regarding the purge valve.....I think you may have found it, but in case you missed it. The vent line needs to go to the charcoal canister first, and then to the purge valve, and then to the nipple on the TB.

The aux purge valve....you probably can elminate. I'm probably going to do that.

Thank you Josh. My coolant routing is looking like it's going to work well. Now just to figure out what to do about an overflow tank with my Koyo radiator and WRX expansion tank.

Regarding the aux purge valve - is it there just to provide a back up to the primary one? You plan to eliminate it would involve taking that line from the charcoal canistor directly to the intake, pre-turbo, and then running a line straight from the intake manifold to the pressure exhange valve?

Finally, the port on the stock TB acts just the same as any other port on the intake manifold correct? I ask because with the EJ20H manifold this port gets blocked off.

My plan would be to block off the third port, or use the two port canister from the non-turbo motors. I don't think you would want to run it vacuum all the time. On the newer non-turbo cars, they have a check valve in the line going to the purge valve. I'm not sure if that's really necessary. It really doesn't hold pressure. I think it's there just to keep the fuel vapors from moving out of the canister.

Regarding the port on the TB, no it is not like any other port. It only has vacuum when the throttle plate is open. If you look at the TB, you'll see that it hits just where the plate is.

Okay. That makes sense.

I guess I'm a little confused now about my situation since I can't use the TB port. Since that line operates using a solenoid that the ECU controls, wouldn't any port coming off the intake be acceptable?

Thanks for the input Josh.

Yeah, any line on the intake should work.