Rated 5.00 out of 5 based on 1 customer rating
(6 customer reviews)




"The Knock Off" high performance stainless recirculating bypass valve kit.

Utilizing a simple and proven single piston design, this dump valve is rebuild-able and also adjustable using the provided 3-spring tuning kit.

Upgrading your bypass valve is highly recommended when adding more power.It also makes for an easy upgrade even for stock motors when your stock Bosch bypass valve is failing.

This fast response dump valve will hold boost better and longer than stock.

Keep in mind that with T7 applications you must use a recirculating valve like this one. T5 applications can choose to recirculate or not.

We package the kit with two sections of silicon hose (choose your color), and 4 stainless silicone hose clamps.

The valve can be mounted in either direction, stock for quiet operation, or reversed for a more audible operation.

Any of the 3 different springs can be used, each has a different spring rate. Most people prefer the red (lightest) spring. Spring weights: red = lightest yellow = middle blue = heaviest

1 year replacement warranty.


Additional information

Weight 4 lbs
Dimensions 6 × 4 × 6 in
Select Hose Color

Blue, Black, Red


  1. Mr E

    I have an ’01 9-5 Aero on a BCB Stg 2 tune. With the plumb back valves, I’ve gone from OEM to eBay to Turbosmart and now BCB’s version and so far, I much prefer it.

    This valve holds my stage 2 levels with more efficiency than any of them and has a quick release reaction time. My boost gauge is also showing about 1+ psi better. So either something fixed itself when I was switching valves or it really is superior to what I’ve ran to date. Installation was very easy and the hoses they supplied are of handpicked quality. Same story with the supplied clamps.

    It is bigger than I was anticipating which nearly limited me on mounting options. It was right up to the body. Initially I was worried as reverse mounting was necessary previously to get the sound level I prefer. This is not the case with this valve. I notice no difference in it’s sound level in either direction. It’s loud both ways!

    Very pleased again guys. I think there’s a trend beginning here.

  2. Brett

    I bought this valve also with some fresh vacuum lines and I is running awesome now. It start up with no issue an the idle stays steady and first gear which never pulled hard at all now has more life.

  3. Matthew Jorgenson

    Recently purchased with stage 2 tune and new vacuum lines for my 05 9-5 ARC. I tried the red spring and it seemed to work ok, I used the yellow spring and it holds the boost really well. I imagine that a stock car would be very happy on the red spring.

    Installation: This is very easy to install, it took some slight modification/creativity to get it to mount up nicely. Definitely VERY easy to do, but it was not a direct swap. (I imagine that any aftermarket BPV will have some fitment issues though)

    Highly recommend this valve, it looks better, sounds better, performs better, and is a great price. Thanks BCB!

  4. Sean K

    Got this and some vacuum lines, the valve went on so easily. I don’t like the blue spring in it, it sounds weird. However, the red spring is good. Definitely pulls harder than before, considering the stock Bosch was leaking some boost. Good product, fast shipping!

  5. Michael Olafsson

    So I purchased this product because after going to Stage 2 on my 02 9-5 AERO the stock BOSCH bypass valve blew apart……was it faulty…or does the boost come on so hard it cant take it, either way it was a good excuse to do yet another upgrade! As always great service and great products!

  6. Rated 5 out of 5

    Tom (verified owner)

    Little background: I have a 2000 9-3 with a TD04 out of a SE/Viggen tuned to 16.5 psi. My old nameless aftermarket DV was faulty (don’t really know how) and only actually opened up fully under full boost. Unless i was nearly flooring the car, it wouldn’t release all of the pressure, and would not only sound utterly depressing but also would force air through the throttle body, causing the car the rev on its own when i shifted.

    I ordered the BCB DV and it came in only a couple days. Right off the bat you can tell that BCB put effort in to packaging the DV, and it was aesthetically pleasing. Installation only took a few minutes because my old DV was stuck on. The provided clamps made installing the new one easy. I sliced off about 3/4 of an inch of one of the provided hoses to make the DV line up a little better, and it worked perfectly. I left the red spring in the DV and even with 16.5 psi, it didnt seem to complain with the red spring.

    After driving it, I was immediately surprised by how much more responsive the DV was. Not only did the valve fully open every time i shifted, but 1st gear finally grew a little hair on its chest, and the car held boost throughout all of the gears much more evenly than the old DV did. My only complaint is the valve isn’t as audible as my old aftermarket one, but overall the valve is 100% worth purchasing.

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