I was wondernig if there was any way to make a blow off valve quiet enough to not be able to hear it but still push 8+ psi. My friend is building a sleeper and is installing the turbo on his eclipse some time soon. Is there any way to make it super quiet with having the bov on?
You can cycle the wasted gas back into your compressor pipe. itll be alil more quiet
what peter said pretty much...its called a recirculating blow off valve or compressor bypass valve. you hook up the exit port of the BOV to a pipe or silicone connector that then connects to the turbo's intake pipe. it'll quiet it down considerably.
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450WHP Turbo Ecotec swap in the works...
i think you can buy a silent one?
Just buy one thats meant for a EVO or a GTi... they both have it so that it dumps the air into your intake... this is mainly for cars with MAP sensors i believe... but that way you will not hear it really... thats probably going to be as quiet as you can get with a Blow off valve... other way is just not use one.... we don't have one on our 87 Buick GNX and we are pushing 30psi of boost... and actually most Grand Nationals don't use them (i don't know any that do) and they are all ruining in the 20-25psi range... are they really are for is too help keep your turbo spining freely between shifts and suposidly help keep the life of your turbo up as it is kind of hard on it with the back pressed of the boosted air on the blades when your throttle body closes... but like i just said we dont run one on our car and its never blown any of the turbos used and thats at a boost level i have yet to see any Jbody run at... (im sure some are though)
The First Twin Charged jbody
blue car (R.I.P) - 240whp @7psi..
silver car - 305whp 315lbs.tq @15psi (91 Octane) or 420whp & 425lbs.TQ @20psi (94 octane+Alcohol Injection)
All dynos run on a Mustang dyno
Josh F wrote:Just buy one thats meant for a EVO or a GTi... they both have it so that it dumps the air into your intake... this is mainly for cars with MAP sensors i believe... but that way you will not hear it really... thats probably going to be as quiet as you can get with a Blow off valve... other way is just not use one.... we don't have one on our 87 Buick GNX and we are pushing 30psi of boost... and actually most Grand Nationals don't use them (i don't know any that do) and they are all ruining in the 20-25psi range... are they really are for is too help keep your turbo spining freely between shifts and suposidly help keep the life of your turbo up as it is kind of hard on it with the back pressed of the boosted air on the blades when your throttle body closes... but like i just said we dont run one on our car and its never blown any of the turbos used and thats at a boost level i have yet to see any Jbody run at... (im sure some are though)
or since finding those cars in the junkyard is almost impossiable any 1g dsm BOV will work.
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Kick azz is my boost hero!!! 
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ok thanks guys for this help. we will get right on that. lol i think hes insane but you would never be able to tell this has anything under the hood. ME one the other hand want to be able to hear the bov just because that means another jbody around here is turboed (witch i have yet to see one)
1g DSM BOV.....cheap and quiet.
Boosted Eco @9psi for now....WRX come spring.....
I have a saab bov for sale. They recirculate the air and are pretty quiet.
Josh F wrote:... this is mainly for cars with MAP sensors i believe... (im sure some are though)
its actually used for turbo cars with a MAF sensors (maybe thats what you meant and just typed wrong) the air is metered before being compressed by the turbo. when the air is dumped to the atmosphere during a shift, the engine runs very rich because the ecu thinks that air is still in the system, so it matches with enough fuel to mix with it....but that air isnt in the system meaning you get a lot of fuel and only a little air. recirculating the BOV dumps the air back into the system - into the turbo intake, after the MAF sensor (because it was already metered) - to avoid the rich condition.
our engines have MAP snesors instead of MAF sensors, so we can vent to the atmosphere without running rich.
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450WHP Turbo Ecotec swap in the works...
