Subaru bov question?

[budsang1]

Not sure what the deal is here, 05 sti, perrin front mount, perrin open atmospheric bov, defi boost gauge said 18.5. This was a little strange as to why it was this high, there is no boost controller on it, but i'm not sure how the wastegate is controlled on subarus.
Car came this way, previous owner gave me stock bov with it, so I put it back on the car tonight. Went for a drive and according to defi boost gauge, I am now hitting stock boost, 14.5-15psi.

I am confused what is causing this, why would switching a bov make this change? Why was it 18.5 to begin with? Could the perrin have been leaking causing a boost spike of some sort? But it saw 18.5 all day every day, very consistently??? Needs some help

Thanks

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[Shadow99]

Could be because there is a different pressure spring in the bov. The aftermarket one could allow more boost into the manifold before it releases it.

 

[Bob Kazamakis]

Subarus come with a stock electronic boost control solenoid. The stock one sucks but can make 20+ psi it'll just taper off drastically.

It's a stock turbo right? I'd keep the stock BBV on it and make sure the tune is good. A good tune is the key to not blowing up a Subaru...otherwise it's pure luck.

 

[Handsome Jesus]

the BOV should have no effect on the process of making boost, unless it got stuck open. even if the BOV was welded shut, the boost control would still be dependent on the wastegate.

perhaps some sort of vacuum leak somewhere? that boost control solenoid has to take a reading somehow.

not an expert on subarus, but as a system in general, you are correct in saying the BOV should have no effect.

another thing to check is where the boost gauge is tied into, as in manifold pressure or pressure in the charge piping.

 

[Prevent]

boost leak ?

 

[SRT41320]

the BOV should not affect this at all - plus the stock BOV's have been proven to over 20psi on these cars... only thing to do would put the aftermarket one back on and see if it goes back up...

 

[Prevent]

my stock one holds toooo 25ish ?

 

[SRT41320]

over 20 im sure! maybe 25....

 

[Spicy McHaggiz]

My 04 hit 25 before the intercooler blew off. (long story)

Do yourself a favor and log onto www.nasioc.com and ask there, you'll likely get the answer you need. I would keep the stock BPV on the setup, and maybe even look into a stock, or aftermarket top mount intercooler. Front mounts, especially on a stock turbo cause headaches.

 

[SRT41320]

:stupid:

 

[budsang1]

Just got another stock bov yesterday, will be putting it on today to see how it reacts

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