WRX Boost question

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JDMPlaya

Senior Member
i've been reading around and saw that a stock wrx puts down 13-14psi, well I noticed that my boost gauge only reads .05 mpa without the boost controller.. what could be the problem?
Mods that I know of are a dp/cat back borla exhaust, boost gauge.. Could I be leaking boost?
I'm a turbo noobie!
 
13-14 seems a tad high, but I'm also up here at altitude.

Do you have an aftermarket uppipe on the car?

In any case, that's definitely low. I'd check to make sure that all vacuum lines are hooked up correctly, and then pull out the ECU and make sure it's not an aftermarket job. Also, check all the connections on the intake side of things...pre-turbo and post-turbo. Make sure all hose clamps are secure, and that all hoses are connected properly.

Failing that, if no one else can offer up suggestions, you might want to start talking to Subaru, or maybe the place that sold you the car. A new ECU from Subaru from be in order.

Also, if you want some better advice, try out a Subaru forum to ask your question. You're more than welcome to hit us up on www.awdpirates.net , there are many knowledgeable people over there.
 
yeah...i second checking the hoses...doesnt sound like the turbo is even connected...like a pipe broke loose or something. any steam or anything from under your hood?
 
I'm not sure if I have an aftermarket upipe, I'll have to get under the car and look..I keep finding more shit done to it,lol

The car runs beautiful, but I think I'm just an idiot, because doesnt boost build up in each gear? in 3rd gear i hit 0.60 bar not even getting on to hard..

Would an uppipe have something to do with that or something?
 
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I'm not sure if I have an aftermarket upipe, I'll have to get under the car and look..I keep finding more shit done to it,lol

The car runs beautiful, but I think I'm just an idiot, because doesnt boost build up in each gear? in 3rd gear i hit 0.60 bar not even getting on to hard..

Would an uppipe have something to do with that or something?
PROBABLY not, but a catless uppipe leads to quicker full spool-up. In rare instances, I've heard of the uppipe failing and either leaking air (which leads to slow or reduced boost) or constricting the flow of exhaust gas to the turbo (same effects as a leaky uppipe).

BUT - the issue here sounds more like a leak on the pressurized intake side of things. I'd check all hoses to make sure they're properly clamped, and also the bypass valve, to make sure it's bolted down correctly. After that, check vacuum hoses to make sure they're not disconnected or punctured.

Drive to Colorado and let us have a look. :laugh:
 
Check first for intake hoses - i.e., intercooler hoses, turbo inlet hose, etc. That's my guess. And possibly the bypass valve (what some people erroneously call the blowoff valve), if it's not connected correctly.

Vacuum lines won't be loose - they'll either be punctured/severed (I've done this) or completely disconnected. It'll be obvious.
 
I'll check it out at lunch, and see if I see anything..do you have a boost gauge? what do usually hit for 1st and 2nd gear and so on when you were stock?
 
The comparisons will be weird, since I'm at 5500 feet above sea level. :) But I believe I was hitting about .08 MPa in 2nd and up (1st isn't good for comparison) when I was stock, which should put you about .09-.10 MPa down at your elevation.
 
Yeah...you can take the BPV off and put on a BOV...i dont know if it messes with the MAF sensor, but i know ive gone by WRXs (not STis) with BOVs
 
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Yeah...you can take the BPV off and put on a BOV...i dont know if it messes with the MAF sensor, but i know ive gone by WRXs (not STis) with BOVs
It does mess with the MAF, but really only between shifts, which isn't a huge deal. The momentary rich condition it causes isn't enough to really affect performance.

A BOV is purely bling on 99% of WRX's. Alternately, you can get BOV's that have a 50/50 split (or adjustable) between blowoff and recirc to try to control the rich conditions.
 
I was thinking.. It couldn't be a boost leak if I can turn up the EBC to about 12-13 psi and it holds there.. right?
 
Maybe when you're putting it back to stock, you're not doing it correctly? Maybe the wastegate is not getting actuated?
 
i made a boost leak tester when I had a leak on my civic.

It's really really simple and cost no more than $10, it only works on the intake side though.

Don't get a BOV, it'll do more harm then good. It's the same way with the 1.8T's.
If you need/want a new BPV, get one from the dealer or STI or make sure its a BPV and will recirculate it. I know with the Audi's, Audi sells an upgraded BPV for like $36, I think it came on the s4's or 2.7TT Allroads.
 
no clue.. maybe your model is older? i dunno. im going by 05 info...cuz its all i know. with a modded car, who the hell knows whats up....
 
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