I have an EJ257 shortblock in my car with the WRX heads on it, an FP Green, and a Greddy FMIC. My problem has been that I can't boost past 17psi. When I go WOT, there is a definite air leak. I've assumed it to be around where I have my BOV (near the intake mani on the FMIC return pipe. I've checked there, as well as all of the hoses around that area (gauge, intake, FBC); no dice.

When I was under the hood today, bypassing the WG, I noticed a flow of air coming from that 'extra' breather ontop of the block. We had put a 1" hose on it, but at the advice of Ron @ Axis over the telephone, he told me to allow it to vent to atmo. This has got to be where the 'leak' is coming from.

Any and all help would be appreciated. Let me know if I haven't given enough detail.

Thanks

 

Stock BOV Pat? It can't handle much more than 17 psi, so go ahead and replace it if that's what you have. But that breather shouldn't have a boost leak- the pressure in the crankcase comes from the PCV system and minor blow-by.

 

Exactly what Is2scooby told me.

I've got that SSQV. I have now put an MBC on (although, now I realize that if I had already completely bypassed the WG, I'm not going to see any more boost by bringing the WB back into the series along with an MBC). Not ironically at all, I am now seeing 12psi with the MBC all of the way out.

Tomorrow, hopefully I'll be able to get my hands on an air compressor and 'pressurize' the intake system.

I now also realize how misguided my thinking was about that crankcase breather, but I do know that I am hearing a rush of air when I'm at WOT. I seriously doubt that the crankcase would be ventilating under that much pressure, so I'm gonna check all of my IC hoses and pipes and such.

At least I've got the fuel where I think it needs to be in preparation for when I start seeing boost (it's drivable now, but very rich so that when a LOT more compressed air starts to enter the intake manifold, it shouldn't be too lean...if that makes any sense.)

 

Try the throttle body connections and the recirc hose. Those are both right next to that breather. Sounds like things are coming together for you.

 

Ok, thanks. I know that the cap is securely in the recirc hose, but maybe I'll double check. The tb hose is on, but I'll be able to see if it doesn't have a hole tomorrow.