My builder explained it this way to me. I haven't researched my warranty to look but this is what he said. "I prefer you go with a bypass rather than a blowoff. It helps prevent a spun bearing." He also said he didn't think that Vortech warrantied that if it happened. He said he asked Vortech about it, they said they hadn't had any problems, so it was his advise I took.

If I remember, and it's been awhile..when Vortech first looked at building an SC for the S2000, they polled this board as to what type it should have.

Anyway he built me a sweet car. It runs great. I follow his advise religously. He hasn't steered me wrong yet. So I have a tendency to believe what he says. I would also note he's done several other S2000's and has an SC'd Civic that runs 12 flat in the quarter mile. If you'd like to talk to him, pm me I'll send you his tel number.

I hope this helps

fltsfshr

 

A compressor by pass valve (CPV) and a blow off valve (BOV) are the same thing. Just different ways to say it. They all have the same function in the end no matter what you call it.

I'd take a stab and say that a reason a lot of you don't hear it is from (1) the boost pressure on being set really hlow (6psi is not a lot of boost, and I think that's what most sc kits produce) and (2) inproper tuning of the valve. On my Greddy Type-S that I was running on my DSM I could hear it very clearly. I was running 16psi and it was releaseing the air back into the intacke track (reirculated). At low boost levels say 5-8 psi all I heard was a little whistle, at 15 I heard a loud ass pssstt. If I adjusted the spring to be stiffer than at low boost I wouldn' hear the whistle, but I did hear compressor surge.

Just gee wiz information.

 

How is something then vents to the atmosphere (BOV) the same as something that vents to the intake side of a FI application (BPV, CPV) to keep a turbo spinning?

 

Yes the difference is the amount of pressure it takes to open the valve blow off are set higher by pass is set lower. I think it's a change of springs?

fltsfshr

 

Ahhhh! You're assuming that the pressure returning to the intake keeps the turbo spinning. This is not the case. The BOV and BPV release pressure that would otherwise stop the compressor. Where they release it to is a matter of manners. The BOV releases it to the atmosphere and gives the fully sick fart noise. The BPV releases it to the intake tract where the majority of it goes back to atmosphere via the air filter and makes very little sound.

Or another way to ask your earlier question would be, 'Why use a BPV when a BOV will do the same thing with a fully sick 'pssssft' noise?'.

I guess the answer is, 'Because we are grown ups!'.

 

I feel like I'm talking to a stick of bubble gum. (no offense)

 

The feeling is mutual.

 

as mentioned before, my vortech lit came with BOV. which brand? I don't know. I was looking into see if I can have HKS SSQV to replace it and than I thought about it.

For what? does it give more control? does it give more pressure? there is NO BENEFIT having better or at least better looking BOV on SC'ed car. as soon as you release gas, it goes off. letting the compressed air out of system so excessive air pressure between SC, Aftercooler, and TB would not hurt any of these part. on this account, I think it's good to have BOV on SC'ed car. any reliable BOV will do.

having DV or BPV on turbo makes sense since it reroutes wasted pressurized air back to turbine so it doesn't have to re-spool. but for Sc'ed car, where are you going to reroute it? to the exhaust? that's same as BOV. to the intake? why would you want pressurized HOT air into the intake? it's not going to make SC spin faster since it's driven by the belt not air pressure. you could put BPV on SC but it doesn't do anything if it doesn't hurt your performance.

 

Thank you nibble. Someone that understands my question.

 

I'm glad to help.