Do I really need a BOV with a vortech SC? I have it venting to atmosphere and the phisssh noise is driving me nuts. Anyone not using a BOV?

 

Yes, you need a bypass. High engine speed and light throttle...all that air has to go somewhere. Without it you will either brake the supercharger or blow off intake hoses. However, if you are running a MAF based controller, you should be venting back into the low pressure side of the supercharger post MAF. Venting to atmosphere dumps air mass that has already been measured. That makes your car run very rich.

 

That's going to depend on the MAF's placement, most are running the BOV before the MAF.

 

Im using a MAP sensor. SC does not build pressure until 3000 RPM so to have it dump at cruise speeds is annoying.

 

You can "vent" it back to the the intake which should minimize the whoosh... but may increase intake temps slightly.

 

Dump it back into the air filter OR replace it with a bypass valve. Those are a lot quieter than blow off valves. I run one Dodge Turbo and one Nissan ZX300TT bypass valves and they are quiet.

 

The reason why I don't run it the bov dump into the intake is because of extra heat in the intake tract. Defeats the purpose of picking up cold air in the fender. I'll see if I can find a pneumatic silencer.

 

Its not a real heat issue, its about 1 sec of some warmer air once you are on throttle..I wouldn't lose any sleep over it.

 

I measured up to a 20f difference dump into intake or not. The intercooler becomes heat soaked. My BOV is 1-1/4", lot of volume of air being dumped at 2500 rpm cruising speed.
I'm going to try this silencer.

http:// http://www.frightprops.com/p...0741-0124.html

 

That's the beauty of a bypass valve. It is always open until it sees boost. So there is no compressed air to heat up the intake air at the filter. Almost all OE boosted engines run this setup.

 

If you weren't building pressure it wouldn't be blowing off...? With the Throttle closed pressure builds very quickly - which us why you really do need it, or something with the same function.

The vent to atmosphere part is the real problem here - muffle it...

Alan

 

dup.

 

If _that_ is heat soaking your IC, you have larger issues.

 

Under normal operation most BOVs stay closed....... They should normally only open when you lift your foot off the gas to prevent a ton of force on the impeller.
During cruise with moderate vacuum they should stay mostly closed........

The design of the BOV is what determines the amount of noise it creates. Maybe look for a quieter version....

 

Hi IMO
Its a muffler not the actual BOV. Yes all OEMs recirculating to the intake because of the venting noise, Ok for daily driver. But venting back into the intake is not the perfect scenario for an sc. Air is being heated by constant beating of the impeller blades at an almost closed throttle plate. Since I'm touching 13 psi of boost, every drop in intake temps matter to keep away from detonation.
For example it was 80f today and I recorded 130f IAT at full boost. Anything done to keep heat out of the engine helps.