BOV making too much noise (Watch bryantaylor turn into a douche bag before your eyes)
#1
BOV making too much noise (Watch bryantaylor turn into a douche bag before your eyes)
Hey Guys,
I have a problem. My TC setup runs a Turbo XS BOV that plumbs back into intake. I'm running a FM Link ECU and a MAP sensor. What happens when I lift off is that the vented air goes out through my open pod filter, making a whole load of noise.
I've actually once dis-connected my plumb back and vented directly to air, and the sounds are comparably loud to each other. I'm now considering taking the plumb back piping and attaching some sound deadening material at the tip and just venting directly to air.
Does this make any sense at all? I've already tightened the spring in the BOV, but i think the sound is just too loud.
Would a factory BCV work softer with a MAP setup?
Is there any benefit to run a Plumb back over atm vented bov on a MAP ECU?
I have a problem. My TC setup runs a Turbo XS BOV that plumbs back into intake. I'm running a FM Link ECU and a MAP sensor. What happens when I lift off is that the vented air goes out through my open pod filter, making a whole load of noise.
I've actually once dis-connected my plumb back and vented directly to air, and the sounds are comparably loud to each other. I'm now considering taking the plumb back piping and attaching some sound deadening material at the tip and just venting directly to air.
Does this make any sense at all? I've already tightened the spring in the BOV, but i think the sound is just too loud.
Would a factory BCV work softer with a MAP setup?
Is there any benefit to run a Plumb back over atm vented bov on a MAP ECU?
#4
Boost Pope
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Indeed. If you want to spend a few dollars, pick up one of the Chinese knockoffs of a Greddy Type S or Type RS BOV from any of the eBay vendors that sell them. Get one with a recirculating fitting on its outlet- most of them only have a noisemaker horn fitting on the outlet.
Open up the BOV and remove the small (inner) spring. The BOV will now leak at idle, but seal up as soon as you step on the pedal.
You can either recirc it or place a K&N filter on the outlet. Either way, it'll give you a fairly subdued sound.
Open up the BOV and remove the small (inner) spring. The BOV will now leak at idle, but seal up as soon as you step on the pedal.
You can either recirc it or place a K&N filter on the outlet. Either way, it'll give you a fairly subdued sound.
#15
Boost Pope
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As delivered, the Type S / RS BOV's are sprung very stiff. All else being equal, the stiffer the spring, the less responsive the BOV will be to small differentials in manifold pressure. A stiff spring may be helpful if you plan to run 30 PSI, but for those of us living in reality it makes sense to soften it up somewhat. This allows the valve to open sooner, relieving pressure quicker and more effectively.
What would be the difference with placing a factory By pass valve instead?
#16
Boost Pope
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Why shouldn't I have? Mine does, and if yours does not then it is not set up optimally.
I usually tend to give people the benefit of the doubt- ie: assume that they are telling the truth, rather than automatically assume that they are flame-baiters. Since you've proven otherwise, next time I'll know to ignore you.
I usually tend to give people the benefit of the doubt- ie: assume that they are telling the truth, rather than automatically assume that they are flame-baiters. Since you've proven otherwise, next time I'll know to ignore you.
#17
Considering that the primary functions of the BOV are to keep the turbo spooled up during shifts and reduce as much as possible the pressure spikes that cause the "gobbling" sound, it makes sense for the valve to be sprung as softly as possible without leaking under boost.
As delivered, the Type S / RS BOV's are sprung very stiff. All else being equal, the stiffer the spring, the less responsive the BOV will be to small differentials in manifold pressure. A stiff spring may be helpful if you plan to run 30 PSI, but for those of us living in reality it makes sense to soften it up somewhat. This allows the valve to open sooner, relieving pressure quicker and more effectively.
As delivered, the Type S / RS BOV's are sprung very stiff. All else being equal, the stiffer the spring, the less responsive the BOV will be to small differentials in manifold pressure. A stiff spring may be helpful if you plan to run 30 PSI, but for those of us living in reality it makes sense to soften it up somewhat. This allows the valve to open sooner, relieving pressure quicker and more effectively.
#18
Boost Pope
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Does that mean that there is benefit in plumbing back to intake? here's my logic. Air under pressure under boost goes back ito intake before the turbo. some of it gushes out of the intake, making the sound that's irritating me, and some of it keeps the turbo spinning in the right direction, reducing lag. Am I being logical here?
The primary advantages of VTA are slightly less plumbing clutter in the engine compartment, and the somewhat theoretical (and very minute) fact that it maintains the velocity of the air through the whole system, including the filter-to-compressor section.
Recirculated systems on the other hand are generally more suitable for vehicles that run an airflow sensing device (AFM or MAF) since a VTA in this situation would have to be valved more stiffly (so as not to leak at idle) than a recirculated system, and thus it would be less responsive.
All else being equal, VTA systems tend to be slightly louder than recirculated systems. In actual practice, much of this tends to do with the design of the valve itself. Some units are specifically designed to be loud, since the kids think this is cool. The HKS SSQV and TurboXS are example. Just look at some of the ad copy: "With new and improved styling, the BOV-H-RFL remains true to it's roots - it's still really f'n loud!"
Many units have removable devices that, when installed, enlouden then. The Type RS is a good example. Have a look:
You see those holes drilled in the outlet horn? Those cause the valve to be loud. When air is rushing out, they cause a sort of whistling effect. If you remove that horn and install a recirculating fitting, this unit becomes significantly quieter.
There is some confusion in terminology surrounding BOVs. You will see the terms "Blowoff Valve" and "Bypass Valve" used interchangeably. Both units are constructed similarly, and both perform the same function. The difference is generally that a Bypass Valve is specifically designed for recirculated use (though it can be left VTA) whereas a Blowoff Valve, from a language-geek standpoint, must be a VTA unit.
#19
Good posts Joe, I might even suggest these be added to the FAQ.
Another thing to note about recirc: some believe recirculating charge air back into the intake to be a bad idea since the air would be hotter than the air the intake would otherwise use. Dodge/Mopar cites this theory in their marketing of the SRT-4 VTA adapter for the stock surge valve.
Another thing to note about recirc: some believe recirculating charge air back into the intake to be a bad idea since the air would be hotter than the air the intake would otherwise use. Dodge/Mopar cites this theory in their marketing of the SRT-4 VTA adapter for the stock surge valve.