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A dump valve and a RX8

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Old 05-08-2007, 10:35 PM
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A dump valve and a RX8

So im thinking of getting a dump valve fitted.......does anyone have any advice or and suggestions theyd like to put to me before i look at getting one. Also does anyone have any recommendations of where to get one online....
Thanks
Old 05-08-2007, 10:43 PM
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Hah. I have two QTP electric cutouts, same as dump valves im guessing that I was going to put into my Audi S4...turned out I never used them so if anyone else actually can chime in, I might put it on my 8 after it gets turbo'd.
Old 05-09-2007, 12:49 AM
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you just cant beat that sound

putcccccccchhhhhhhhhhhhhhhhh

i cant express it with words
Old 05-09-2007, 06:59 AM
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Actually..itll make the car sound alot deeper and throatier...closer to V8 sounds in my opinion. They sounded great on the S4's, never even thought about the Rx though I'm going to try and do some research and see if it can actually work..
Old 05-09-2007, 08:13 AM
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NOTHING will make a Rotary sound like a V8.

I say do it if you want but that would be WAY too loud for myself.
Old 05-09-2007, 08:28 AM
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What's a Dump Valve?
Old 05-09-2007, 02:36 PM
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Originally Posted by Alano
Actually..itll make the car sound alot deeper and throatier...closer to V8 sounds in my opinion. They sounded great on the S4's, never even thought about the Rx though I'm going to try and do some research and see if it can actually work..
Sounds like a step in the WRONG direction! Why would you want it to sound MORE like a V-8? So you can blend in with 5-trillion Mustang owners? Sounds cool, man!
Old 05-09-2007, 02:52 PM
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Originally Posted by devildog1679
What's a Dump Valve?
Dump valves are fitted to the engines of (usually older) turbo charged cars and sit between the turbo outlet and the throttle body. When transitioning from a boosted state to a closed throttle state (as in between shifts), due to inertia, the turbo continues to pressurize air, but the closed throttle prevents the compressed air from entering the engine. In this case the pressure exceeds the preset spring pressure in the dump valve and the excess pressure is bled off to atmosphere.

Even with a dump valve the compressed air acts as a brake on the turbo (slowing it down), because the pressure on the backside of the turbo is at a higher pressure than on the front side (and the air actually wants to flow through the turbo backwards).

A blowoff valve is a more elegant solution to this problem by allowing the turbo to "freewheel" when the throttle is closed (equalizing the pressure on both sides of the turbo). Unlike a dump valve a blowoff valve can be used at multiple boost settings without reconfiguration.

Blowoff valves are sometimes incorrectly called dump valves because they serve a similar function, however they are very different solutions to the same problem.
Old 05-09-2007, 04:26 PM
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Originally Posted by NoTears316
Dump valves are fitted to the engines of (usually older) turbo charged cars and sit between the turbo outlet and the throttle body. When transitioning from a boosted state to a closed throttle state (as in between shifts), due to inertia, the turbo continues to pressurize air, but the closed throttle prevents the compressed air from entering the engine. In this case the pressure exceeds the preset spring pressure in the dump valve and the excess pressure is bled off to atmosphere.

Even with a dump valve the compressed air acts as a brake on the turbo (slowing it down), because the pressure on the backside of the turbo is at a higher pressure than on the front side (and the air actually wants to flow through the turbo backwards).

A blowoff valve is a more elegant solution to this problem by allowing the turbo to "freewheel" when the throttle is closed (equalizing the pressure on both sides of the turbo). Unlike a dump valve a blowoff valve can be used at multiple boost settings without reconfiguration.

Blowoff valves are sometimes incorrectly called dump valves because they serve a similar function, however they are very different solutions to the same problem.
Notears thats some really good info. So after reading what you wrote i have second thoughts about it now, i dont want my car to slow down
Old 05-09-2007, 05:23 PM
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Originally Posted by DonJuanMair
Notears thats some really good info. So after reading what you wrote i have second thoughts about it now, i dont want my car to slow down
I think you misunderstood what I typed. Your turbo (I'm assuming you have one) will slow down due to the the compressed air. A dump valve helps, but isn't as effective as a blowoff valve.

With the implementation of a blowoff valve the pressurized air escapes, allowing the turbo to continue spinning. This allows the turbocharger to have less turbo lag when power is demanded.
Old 05-09-2007, 06:08 PM
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Originally Posted by NoTears316
Dump valves are fitted to the engines of (usually older) turbo charged cars and sit between the turbo outlet and the throttle body. When transitioning from a boosted state to a closed throttle state (as in between shifts), due to inertia, the turbo continues to pressurize air, but the closed throttle prevents the compressed air from entering the engine. In this case the pressure exceeds the preset spring pressure in the dump valve and the excess pressure is bled off to atmosphere.

Even with a dump valve the compressed air acts as a brake on the turbo (slowing it down), because the pressure on the backside of the turbo is at a higher pressure than on the front side (and the air actually wants to flow through the turbo backwards).

A blowoff valve is a more elegant solution to this problem by allowing the turbo to "freewheel" when the throttle is closed (equalizing the pressure on both sides of the turbo). Unlike a dump valve a blowoff valve can be used at multiple boost settings without reconfiguration.

Blowoff valves are sometimes incorrectly called dump valves because they serve a similar function, however they are very different solutions to the same problem.
Thank You
Old 05-09-2007, 09:32 PM
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Originally Posted by NoTears316
Dump valves are fitted to the engines of (usually older) turbo charged cars and sit between the turbo outlet and the throttle body. When transitioning from a boosted state to a closed throttle state (as in between shifts), due to inertia, the turbo continues to pressurize air, but the closed throttle prevents the compressed air from entering the engine. In this case the pressure exceeds the preset spring pressure in the dump valve and the excess pressure is bled off to atmosphere.

Even with a dump valve the compressed air acts as a brake on the turbo (slowing it down), because the pressure on the backside of the turbo is at a higher pressure than on the front side (and the air actually wants to flow through the turbo backwards).

A blowoff valve is a more elegant solution to this problem by allowing the turbo to "freewheel" when the throttle is closed (equalizing the pressure on both sides of the turbo). Unlike a dump valve a blowoff valve can be used at multiple boost settings without reconfiguration.

Blowoff valves are sometimes incorrectly called dump valves because they serve a similar function, however they are very different solutions to the same problem.
wiki much?
Old 05-09-2007, 09:39 PM
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Originally Posted by N rider89
wiki much?
Why do the work when teh internets can do it?
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