Blow off Valve on the Turbo.

[Fosgate]

Noticed RPM power sports has a charge tube and blow off valve kit. Charge Tube with BLow off Valve
I have a lot of respect for the blow off valve on my Rzr XP Pro Ultimate pushing well over 200hp. I like the idea of reducing the pressure of that turbo spooled up when you let off the gas rather than the engine taking the abuse and reducing the life of the engine. That said, at first I saw it and thought I would grab one but then I thought about it and figured I would wait. Here's why.

On my RZR before adding the blow off valve It was like a pit bull ready to kill everything all at once, turning from one to the next without stopping so to speak. If you let off the gas, that pressure built up took a few extra seconds to back off that when you got into the gas again you it was right there spooled up ready to kill again unless you hit the brakes to call it back. After the blow off was added it's like it killed, came back quickly and start all over on the next one rather than carry the momentum through the pressure built up. Took me a little while to get used to as I found myself having to work both feet on the brake and gas to keep it spooled into the power band.

This is where I'm thinking I'll just need to try the new boost the way it is with a can as the only aftermarket item to start and see. I generally like to carry momentum and see that the blow off valve on a sled, while may prolong engine life, think it may have a negative reaction to the way I like to ride. I think that blow off every time the throttle is released rather than the brake being applied only when you want it to slow down may work against me. Anyone else have thoughts on this?

 

[diamonddave]

I think the simple question is why would the boat anchor need a blow off valve? Respect to the aftermarket for innovation but I can think of many reasons why it’s not needed with this design and in this application while riding in tight tree deep chop.

 

[Sheetmetalfab]

I assumed it was for parking lot posers making pshhh noises

 

[simnil]

Noticed RPM power sports has a charge tube and blow off valve kit. Charge Tube with BLow off Valve
I have a lot of respect for the blow off valve on my Rzr XP Pro Ultimate pushing well over 200hp. I like the idea of reducing the pressure of that turbo spooled up when you let off the gas rather than the engine taking the abuse and reducing the life of the engine. That said, at first I saw it and thought I would grab one but then I thought about it and figured I would wait. Here's why.

On my RZR before adding the blow off valve It was like a pit bull ready to kill everything all at once, turning from one to the next without stopping so to speak. If you let off the gas, that pressure built up took a few extra seconds to back off that when you got into the gas again you it was right there spooled up ready to kill again unless you hit the brakes to call it back. After the blow off was added it's like it killed, came back quickly and start all over on the next one rather than carry the momentum through the pressure built up. Took me a little while to get used to as I found myself having to work both feet on the brake and gas to keep it spooled into the power band.

This is where I'm thinking I'll just need to try the new boost the way it is with a can as the only aftermarket item to start and see. I generally like to carry momentum and see that the blow off valve on a sled, while may prolong engine life, think it may have a negative reaction to the way I like to ride. I think that blow off every time the throttle is released rather than the brake being applied only when you want it to slow down may work against me. Anyone else have thoughts on this?

The theory behind the blow off valve is actually exactly the opposite to what you describe. It's supposed to evacuate pressure rather than force it back through the turbo which will abruptly reduce impeller speed.
Because of that the impeller remains at a higher RPM and thus react quicker and reduce spool up time next time you hit the throttle

 

[ndfb35]

Worked well on my turbo Cat. Much better throttle response when on and off but it took some tinkering to get it set at the right pressure.

 

[madmax]

Wouldn’t be one of the first things I’d buy, but maybe later. Here’s a good read that explains it, but In the automotive world where boost pressures are much higher than a factory 2-stroke turbo.

https://gfb.com.au/tech/tech-articles/11-the-truth-about-compressor-surge/

 

[Fosgate]

Wouldn’t be one of the first things I’d buy, but maybe later. Here’s a good read that explains it, but In the automotive world where boost pressures are much higher than a factory 2-stroke turbo.

https://gfb.com.au/tech/tech-articles/11-the-truth-about-compressor-surge/

Cool thanks. I’m still learning all this turbo stuff. I just recall 20yrs ago how fussy turbo sleds were and how often they went down. When I bough my my razor this summer I priced engines and noticed for rebuilt they run $6k up. I wanted to reduce the risk of the engine going. First things my research showed to help increase engine life was add a dump can and blow off valve.


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