I'm aware that the stock bypass valve included with the Vortech kits will not flow enough air for higher boost/volume applications, will a 37mm BOV be adequate of do I need the 50mm BOV?

 

You cna get a 47mm type R greddy valve for about $208.

 

Will a BOV replace the bypass valve or do I still have to have the bypass valve? Some people are saying that the BOV only releases pressure spikes and the bypass valve releases boost only under vacuum, but the BOV has a vacuum line to. Someone please tell me the difference between the Bypass valve and a BOV.

 

Blow off and bypass valves are the same thing. They are reffered to as blow off valves when the air is permitted to blow into the atmosphere, and bypass valves when they route the air back to the intake side of the blower. Both configurations are actuated when manifold vac. is high- ie. light load/cruise cond. or when the throttle blades are closed abruptly. At cruise you don't want/need boost, so pressure is bled off, and just think when you are at 6500 rpm at the end of the strip for instance and you take your foot off the throttle the motor is still spinning the blower at the same speed exept now the blades are shut! This creates tremendous pressures and could damage yor impeller or blow you piping off (as happened to me) if a bov/bypass valve were not in use.

 

I did a search on here before I made this post and there seems to be some dissagreement as to how each one works, some say that the bypass valve is normaly open and closes under boost and that the BOV is normaly closed and just opens with pressure spikes, this did not make sense to me however. I think they mey have been thinking about a wastegate, which releases excess pressure with turbos to keep from providing too much boost. Would you think that the 37mm BOV would be adequate for my application?

 

well with the motor running in park my blow off valve still gives off a small amount of air. like said above they are the exact same device. BPV is mainly/purpose is to recycle the air. BOV is to release into the air instead of reusing it. you can run both...

 

You have the BPV and the BOV right. A wastegate vents exhaust gas around the turbine of a turbocharger to keep it from spinning any faster.

 

How are you plannig on having this thing tuned?? Alot of people run the bypass with turbo kits and blowers in the F-body because they are using the MAF system. Its no prob to run a big BOV like a Tial 50mm( what I am using) if you are running an aftermarket DFI, but with the stock ECU you will have to have a really good tuner account for the pressurized air that is bled into the atmosphere by the BOV instead of back through the system in the cas of the bypass. BOV's are alot cooler and sound mean as hell. I have heard having them tuned is about finding the right person to do it, but its never as good as a DFI speed density setup. I would buy the TIAL 50mm.

 

I'm relocating the MAF to the pressure side after the intercooler so that the bypass valve can vent to the atmosphere before the air is measured by the MAF (I decided to go with the Vortech Mondo Bypass Valve). I'm getting a baseline tune from Ion as a starting point then I will dial it in more with LT1 edit on the local chassis dyno. In case anyone else is looking for info about the difference between an Bypass valve and a blowoff valve I'll put it in writing here. I called GReddy and Vortech and spoke with the tech departments of both companies. The BOV is normally closed and only vents at pre set pressures and sudden throttle closing events were there is a pressure spike. The bypass valve is normally open under idle and part throttle cruising but closes under boost and opens during sudden throttle closing events to release pressure spikes. They are similar exept the part where one is normally open and the other is normally closed. The supercharger needs the bypass to release pressure at idle and part throttle because a supercharger can still produce small amounts of boost at these RPMs regardless of engine load. A turbo generally does not produce boost until the engine is under load so it can have the BOV normally closed.

 

I haven't ever heard of anyone putting a BOV on a S/C car. Does anyone have and Videos?