Is it possible to put a BOV on a D/A Supercharger?

[FiKtIOn]

I still dont understand how it would work on a sc...Its controlled by pulleys, therefore when you close the throttle body(i.e. letting off the gas) the pulleys stop moving...I dont see where the excess spin is coming from since it is driven by your rpms, they are gradually going to decrease as you close your throttle body...

[Solokron]

If this has been done on a SC I would like to see pics and a sound file. I can't see it being very effective in producing a high bov sound.

Originally posted by Magic M3
Jags M3.... you can put a BOV on your Supercharger. It is a centrifugal so you should have a pipe that goes between your supercharger and throttle body. Just put the BOV inbetween there. It takes drilling a hole in the pipe and welding the BOV on to it. Good luck.

[E36M3]

As someone has already stated, SC's have a bypass valve which opeartes in a "similar" way that a BOV does. The advantages of using an air bypass valve includes eliminating compressor surge (the noise heard during deceleration) for quieter supercharger operation, and reduced heat soak in the discharge tube and the supercharger.

If you want a BOV just for the sound, go buy the PA speaker system that APC sells.

[kumanchu]

Originally posted by E36M3
As someone has already stated, SC's have a bypass valve which opeartes in a "similar" way that a BOV does. The advantages of using an air bypass valve includes eliminating compressor surge (the noise heard during deceleration) for quieter supercharger operation, and reduced heat soak in the discharge tube and the supercharger.

If you want a BOV just for the sound, go buy the PA speaker system that APC sells.

the turbo equivalent of this bypass valve is actually the wastegate; which reroutes air going to the compressor from the intake side of the turbo manifold.

[Agaponi]

oh my god kumanchu , your turbo knowledge is so mess up.
Your confusing wategate with BOV or BPV...
Wastegate is (internal or external) the valve that is attached BEFORE the EXHAUST GAS go to the turbine, so when you dont WANT or NEED (thats the way you program a turbo to build boost) the wastegate open (so the turbo slowly stops spinning too much), or close (so the turbo keep spin). go to turbonetics site if you want to see a wastegate.

A blow off valve is between the turbo compressor and the TB, the ONLY function of this (ITS NOT TO CONTROL THE TURBO!!!!, that is the wastegate), is to vent the high pressure around the pipes (only when the TB is closed, thats why you tap the BOV to a vacuum/boost signal comming from the INTAKE manifold, so the BOV know when the TB is closed/open) so the boost dont come back to the compressor side of a turbo and "slow" the impellers down between shifts. A BOV is the exact same thing as a divert valve (or bypass valve). The ONLY difference is that the BOV vent the air to the atmosphere and the BPV or DV vent this air to the intake side AFTER!!! the MAF so the air/fuel stays the same and perfect.
Usually this DV or BPV are used on OBDII cars, because this cars doesnt only use MAP sensor, but it use the MAF to control the A/F ratio, and a BOV will release air to the atmosfer, and make the ECU think it this air inside the system, and then put more fuel to compensate this "air" that is never in, so thats why you run rich at idle or between shifts...

Learn more about FI, before post in here and say that kind of things...

[kumanchu]

Originally posted by Agaponi
oh my god kumanchu , your turbo knowledge is so mess up.
Your confusing wategate with BOV or BPV...
Wastegate is (internal or external) the valve that is attached BEFORE the EXHAUST GAS go to the turbine, so when you dont WANT or NEED (thats the way you program a turbo to build boost) the wastegate open (so the turbo slowly stops spinning too much), or close (so the turbo keep spin). go to turbonetics site if you want to see a wastegate.

A blow off valve is between the turbo compressor and the TB, the ONLY function of this (ITS NOT TO CONTROL THE TURBO!!!!, that is the wastegate), is to vent the high pressure around the pipes (only when the TB is closed, thats why you tap the BOV to a vacuum/boost signal comming from the INTAKE manifold, so the BOV know when the TB is closed/open) so the boost dont come back to the compressor side of a turbo and "slow" the impellers down between shifts. A BOV is the exact same thing as a divert valve (or bypass valve). The ONLY difference is that the BOV vent the air to the atmosphere and the BPV or DV vent this air to the intake side AFTER!!! the MAF so the air/fuel stays the same and perfect.
Usually this DV or BPV are used on OBDII cars, because this cars doesnt only use MAP sensor, but it use the MAF to control the A/F ratio, and a BOV will release air to the atmosfer, and make the ECU think it this air inside the system, and then put more fuel to compensate this "air" that is never in, so thats why you run rich at idle or between shifts...

Learn more about FI, before post in here and say that kind of things...

uh, i kno what a wastegate does; i'm not really fully understanding the bypass valve in the supercharger aparently.

can you answer tho; what function a BOV on a supercharger would be other than a boost leak?

[Agaponi]

ok, if you put a BOV on a S/C, and connect it with a line that goes to the intake manifold (the same way for the turbo), then the only function will be releasing pressure during shift to prevente S/C (and mostly TB) damage because of the pressure. Remember, when you shift, the TB is closed, but the S/C keeps building boost because your still in high rpm.
You could also use a BOV (if you DONT connect it with a vacuum/boost line) to open at certain boost, so you can "control" boost on a S/C at desire. But that is the worst way to do it, because it will be very inefficient... the S/C will make too much hot air for lower boosts... The only efficient way to control boost on a S/C is the pulley size.

[kumanchu]

the TB should never really be fully closed but granted it can be restrictive enough to cause a sort of mild pressure surge and put stress on the compressor of the S/C.

in anycase; you still point out that its a bad idea and so still my question goes unanswered, is there any GOOD reason to have a BOV on a supercharger?

*bling *blings and goes pshhhhhhhhhhhhhhhhhht

[Agaponi]

A S/C MUST have a bypass valve, because like you said, pressure will put too much stress on the compressor between shifts.
You can put a BOV if you want, it wont do no harm.
I really recomend a BOV for +8psi systems S/C, because with that kind of boost, the bypass maybe not doing a 100% complete job, and so a BOV may help here.
for a 5-6psi setup, it will be overkill, but if you like the sound... go ahead It really wont do any damage, just prevent something that wont happend (because the bypass will take care of that).

[Solokron]

So the following would be the correct method of implementing a BOV on a SC?

"Jags M3.... you can put a BOV on your Supercharger. It is a centrifugal so you should have a pipe that goes between your supercharger and throttle body. Just put the BOV inbetween there. It takes drilling a hole in the pipe and welding the BOV on to it. Good luck."

[Agaponi]

yes, thats correct. Also remember to install the vacuum/boost line to the manifold (or make a T-connector in the FPR vacuum/boost line). That way you get the psshhhh sound, and more S/C reliability.

[///Ti]

All right, the time that a BOV is useful on any SC car is when you take your foot off the gas, the second you do that your butterfly in the throttle body snaps shut. The engine RPM don't fall immediately, they take a second or two there for the compressor is still spinning and there is pressure being crated between the TB and the supercharger. in this situation you could use a BOV, BUT the main reason that they are used in turbo systems is because that boost created by the turbo still spinning will create quite a bit of shock to the system, and over time screw up your seals and bearings in the turbo. The issue with the supercharges is that they are more durable and will slow down much faster, its faster not instant, there for its not needed, so a BOV could be used but vital. The main problem is that most SC bolt right onto the intake manifold and there is no piping to mount a BOV, this is depending on the SC you have. If i had a SC car id give it a try cause it cool, yeah people think that just having a BOV for the sound is lame and a waste of 3 bills but its up to you, hope this all helps

[Stealth]

so being that the downing/atlanta is a positive displacement supercharger that not only mounts to the intake manifold but also relocates the TB no you cant put one on a D/A sc

[Agaponi]

thats right!
for a S/C with low boost (like 6 or 7psi) a BOV will be overkill... but when your using like the RMS stg 2 or 3 with high boost (11-13psi) a BOV will prevent the S/C for premature damage, and you will have more reliability. Also, remember the S/C is not the only part under stress... the TB gets too much pressure from this shifts (remember this type of TB is not designed for FI applications).

[stimpee]

Originally posted by Stealth
so being that the downing/atlanta is a positive displacement supercharger that not only mounts to the intake manifold but also relocates the TB no you cant put one on a D/A sc

You may not be able to use a BOV, but a bypass valve gives major benefits in a PD SC setup. It relieves the SC of load under vacuum so there is nearly no parasitic drag during idle and part throttle cruise conditions, therefore minimal penalty on fuel economy.

Even a bigger benefit than the purposes of putting it on a centrifugal setup IMHO...

Steve