Mach1StanG

Whats the difference? I put an intercooler on my vortech and had the blower upgraded to a t trim along with the forged rods and pistons. The guy that did everything had a procharger bypass around and said that would be better then the vortech one that was on my system originally. I was wanting to upgrade to a louder bypass blowoff any ideas?

ravenforbidden

The blowoff valve helps get rid of the pressure when youreach set boost to maintain consistancy, basicly helps so your valves, anywhere really it'd be a big issue if not. A bypass however works to remove pressure when you let off the pedal, you need both in Centrifugal Boosting. You only really need a Bypass for a roots or twin screw as they back down alot better with the motor because they're fixed ratio.

I'm working on aHP Turbo Twin Turbo 76mmEquipped 89 GT 5.4 Small Block and right now from what I've researched the bigger the boost the better these need to be. Intercoolers are good too, but an air to air is better for longer use than the strip, otherwise it's effect is short lived in my experience. HOWEVER, Water to air intercoolers whoop *** when you pack em with ice for single style runs.

r.barn

^^^^ Wrong.

A Bypass Valve and Blow Off Valve are same thing.
The relieve pressure in the intake tube when you close the throttle.

A s/c control boost pressure with pulley size
a turbo controls boost pressure with a wastegate that keeps turbo from spinning as much.

If you have a blow thru MAF you have to recirculate the Blow Off air back into the system
People usually call those Bypass Valves instead of Blow Off Valves, but they are the same exact thing
One just vent to open atmosphere the other back into the intake system, usually right before the s/c


If you want "SWISH" blow off sound, you need to to get a blow thru MAF and just
put the BOV infront of the MAF on the intake tube.

samseed101

Actually, he is right about that part. A BOV will release the air at a preset pressure. That is why you get that whoosh sound that you're talking about. A bypass valve, on the other hand, is ALWAYS open until the vacuum level drops when you are at WOT. An easy way to see what I mean is to have both cars sitting at idle... The bypass valve will be wide open and blowing air. The BOV will be closed.

Also, a BOV can recirculate air while a bypass valve can vent to teh atmosphere. Matter of fact I have a bypass valve that vents to teh atmosphere. But it's still a bypass valve. It stays wide open until I hit WOT and the vacuum level drops.

A BOX is bad on a supercharger because they really aren't designed to be able to handle the pressure in that manner... obviously due to teh fact that they are belt-driven. A turbocharger, on the other hand, doesn't have that issue, and therefore it can use a BOV with no problem.

You also got one part backwards. If you have a blow through MAF, then yoiu don't need to recirculate the air and you can vent it to the atmosphere. It's teh draw through setups that need to be recirculated because the air is metered.

But getting back to the original topic, they are indeed two different things that operate in two different ways. Come on r.barne, I know you know this stuff already [8D]

samseed101

Although thinknig about it... the two terms have been used that way for so long that I suppose it's almost common practice now. But it doesn't mean that it's right Just like people who install "NOS" on their car. Well, they use the term NOS when talking about any nitrous setup. Technically it's incorrect, but I guess it has been accepted.

But if I were to order an actual BOV and install it on my car to vent it to the atmosphere, I would have problems due to the fact that it would not open until reaching a certain level, whereas my bypass valve only closes when it meets certain conditions.

SlvrOhTwoGeeTee

I thought that a bypass recirculates and a blowoff vents... isnt that why th BPV has a hose that goes back to the intake tube before the S/C and why turbo cars go WOOOOOSH... I like that sound.. I could be wrong as I am not runnig either of these power adders, but I remember I had an RX-7 turbo and it had a BOV that vented.

samseed101

Yes, that is the typical setup, however they are still two very different monsters. I should meet up with you sometime, since I work in Saco anyway, lol. I have a bypass valve (not a BOV) but mine vents to the atmosphere. However, it is a bypass and therefore is open most of the time and ONLY closes when I hit WOT. If it were a BOV, it would stay closed a lot more and would make that sound you're talking about between shifts, etc.

SlvrOhTwoGeeTee

I see. Do you have a Blow-thru MAF? If not how do you compensate for the air lost through the BPV that has already been accounted for by the MAF?

nanaki

a bypass makes that whooosh noise too

samseed101

It's a Procharger, of course it's a blow through MAF. It's the 3" PMAS Pro-Tube. The air is unmetered so it can and does vent directly to the atmosphere. You can put your hand in front of it at idle and feel a ****load of air blowing through it. Then hit the throttle a few times to rev the engine and you can really feel it pushing hard.If it were a BOV, you wouldn't get that effect.

It's pretty loud when you come out of boost when decelerating and you get that loud whoosh sound, but you don't get it between shifts like you owuld with a BOV. And if you're at a high RPM in a low gear you can really hear it too. Mine is LOUD!