WRX Sti BOV Upgrade - Recommendations & Advice

Hi Guys

Looking to upgrade my stock BOV. What do you guys recommend that sounds nice (and OZB cheap!).

Also, would I need to have the car tuned for a BOV?



  • Block it off.


  • initial D still a thing?

  • Waaaap ptshhhh

  • Ask superwog uleh..

    I think GoFastBits, Aus parts store, make a BOV to suit the WRX flange

  • Don't go BOV without a tune unless you can afford a new shortblock!

  • Block it off, flutter the world.

  • lol.. you dont need a bov unless youre running a heavily built engine..save your $$

  • Not sure why all the digging comments, nothing wrong with a more audible blow off valve. If you want more turbo noise, do an intake and a turbo-back exhaust. As for needing a tune, yes, you need a tune for blow off valve, intake and any exhaust work between engine and cat. You need a tune as the car will handle air intake differently

    • You do not need a tune for a bov. At all.

      • You don't need to, no. It is definitely recommended if you want your car to run efficiently. Bov's affect AFR

        • No they don't. They are shut unless the throttle is snapped closed while there is boost in the intake piping. On a car with an air flow meter they will cause a very short rich spike when you snap the throttle shut, that is all, and only if it vents to atmosphere.

  • Subaru spent millions of dollars on R&D so you could fit a $50 part to your car, just so it makes a stupid noise.

    Might want to check state laws on that noise before to go changing how it sounds…

    And if you are doing it just for the sound, just get a BOV emulator. Makes the same sound, can turn it off if the coppers are about and doesn’t require modifications to the engine.

    • Just a more general comment that, Yes Subaru spent millions in r&d to make a car to a specific price point that meets certain criteria. E.g. WRX is a relatively fast, decent handling, ugly car, that meets it's target market.

      Millions of engineers in the specialist car part industry focus their attention on improving the parts that the Subaru engineers needed to compromise on (usually due to financial pressures).
      For example, the standard suspension might be fine for most situations and met the cost/ride/handling for marketing, but some people are happy to further compromise the ride quality to have better handling, so the engineers in the suspension parts industry see an opportunity and make aftermarket parts for that car with those characteristics.

      As for a BOV, I hope OP never has to drive past my house with that stupid noise.

  • Just chuck a pod filter in of sorts and it'll have a similar effect at both making you think it's faster, and attracting attention from HWP.

  • My recommendation is don’t do it so you don’t look like a (profanity).

  • Go and find a WRX forum and ask there for the best response.

    +1 for checking local laws, might be something you could get defected for. We all know how much the highway patrol love targeting modified cars.

  • What year is your wrx?
    If you prefer to not need a tune simply get one that vents to the atmosphere as well as back into the system not one or the other.
    That way the ecu gets what it needs and you get what you want out if the bov, win win

  • Haven't heard a show off valve in ages and I have a WRX STI.

    Go Duck BOV

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