Sounds like the spring screw needs to be adjusted.

edit: if it has an adjustable spring.

 

Adding Shims/Washers to BOV Aftermarket Assassins

First-time post here as I recently got a 2021 rzr turbo 2 seater. I installed the Aftermarket Assassins stage III kit with the BOV and filter. I have noticed with the BOV and filter installed I really like the BOV sound but I do notice a lot of vacuum noise while cursing that can be annoying...

www.rzrforums.net

 

I had the exact same issue with my AA bov. No amount of adjustment would get it good enough. It did get better. But still hissing under mild acceleration.

After some extensive reading, i ended up purchasing a cheap RKX bov as noted in this thread…

Inexpensive BOV done right >>>

A while back there where several threads about BOV that had a lot of misinformation in them. I will try to clear up some of the misconceptions show how to setup a inexpensive BOV for use on the XPT. 1) All Blow Off Valves / Diverter Valves work the same way. 2) A BOV and a Diverter Valve are...

www.rzrforums.net

I didn’t use the cheap bov, I kept the AA bov. The cheap one came with three springs and some shims. I used the stiffest spring, and used trial and error to get the shim setup right. Now mine never hisses, and only vents as it should when I let off the accelerator.

Basically, the AA bov spring is too weak. You could contact AA about a different spring, but the RKX is too cheap to bother. Get one from the interwebs in a couple days and be done with it.

 

I didn’t use the cheap bov, I kept the AA bov

The AA BOV is a cheap rebranded Chinese knockoff but you paid 3x the cost for the label 🤔

 

What tune are you running? Ive got the same bov without issue and im running his stage 3 setup most of the time.

 

I've been running the aa Bov for 7000km on my pro xp. It hisses under partial acceleration which is 100% normal and under full load it's quiet. It blows off like it should at full throttle. That's the way it's designed to work. Rpm sxs bov does the same thing and there's a video on this.


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I got it to run like normal now but this thing is just hissing like crazy the whole time you are driving, im just running the stock tune, machine only has 15 miles on it now. It sounds good but definitely louder than hell and annoying after about 5 minutes in the machine, I am going to get heavier springs for it. The problem was it wasn't seating in the charge pipe all the way, after getting it outside in the daylight I could see the problem.

 

You can also vent it back into the intake pipe if you want it really quiet.


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I wanted a loud blow off valve, just not one that constantly screams.

 

I’d send it back or call AA.

 

Has anyone heard both the Aa and rpm sxs bov? Wondering if they sound similar or which sounds better. I've only heard the Aa on me myself. And videos usually don't represent a true sound.


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Has anyone heard both the Aa and rpm sxs bov? Wondering if they sound similar or which sounds better. I've only heard the Aa on me myself. And videos usually don't represent a true sound.


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For me it was a toss up as to which one I was going to buy between those 2, they look identical, probably are the same, but aftermarket assasins had better reviews and I want the rest of their items to make mine a stage 3 so I went with there's.

 

Replace it with an EVP BOV

Billet Blow Off Valve (BOV) Kit for Polaris RZR

Description Evolution Powersports was first in the industry to design and produce a Blow Off Valve (BOV) specifically for small displacement factory turbocharged engines. Virtually every BOV on the market was designed for automotive applications which have different requirements in terms of...

evopowersports.com

 

I have the RPM SxS BOV on mine. Super easy to install, makes a great sound, was cheap. BOV are some some crazy tech, they are just a valve. They should whistle at partial throttle, and close up and higher speeds/throttle. Don't waste money on an expensive BOV. All of them are stronger than the stock one. None of them add any performance.

 

They seem to be able to reduce performance...

A good valve will have tight tolerances. Whether or not that's worth it to you, is up to you.

 

I don't know, I just installed a cheapo BOV my buddy got off AliExpress for $20, it looks identical to the AA BOV, works exactly the same, same psi in the charge tube as the stock one....I'd spend your money elsewhere.

 

Yeah the stock plastic one was garbage, I accidentally dropped it in my garage and it broke in half!

 

Totally agree, anything that affects performance or reliability, spend money on the higher end parts. Anything else, just throwing money away imo.

 

Hissing could also be a boost leak