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View Full Version : By Pass Valve Vent or into the intake


JamesJ
12-20-2007, 03:59 PM
I am looking at my different options and the design of my by-pass valve.

The first questions is should I have it release into the engine bay (atmosphere) or should I send it into the intake of the blower?

The second question is what level of a by-pass valve should I use? What I am referring to is if the standard black valve that comes with the ProCharger sufficient or should I get the red one that is designed to handle more boost. Also there are other companies that make bypass valves that are smaller than the red one that ProCharger sells. Some call this a race version or a positive seal unit.

I have also heard that when you run 12psi or above that you need to dump the extra boost into the atmosphere and you need to run a better by-pass valve.

I am using a D-1SC that should make up to 12 pounds of boost. The motor is a 383 SBC . I will also be using an intercooler.

Any Ideas?

camcojb
12-20-2007, 04:04 PM
I am looking at my different options and the design of my by-pass valve.

The first questions is should I have it release into the engine bay (atmosphere) or should I send it into the intake of the blower?

The second question is what level of a by-pass valve should I use? What I am referring to is if the standard black valve that comes with the ProCharger sufficient or should I get the red one that is designed to handle more boost. Also there are other companies that make bypass valves that are smaller than the red one that ProCharger sells. Some call this a race version or a positive seal unit.

I have also heard that when you run 12psi or above that you need to dump the extra boost into the atmosphere and you need to run a better by-pass valve.

I am using a D-1SC that should make up to 12 pounds of boost. The motor is a 383 SBC . I will also be using an intercooler.

Any Ideas?

Procharger told me the standard bypass is good to 650-700 hp or so. We used one on my friends 700 rwhp car and never had a problem. I opted for the larger red one on my Procharged 540.

I've always vented to atmosphere but venting into the inlet piping to the blower would be quieter.

Jody

comp-spec
12-20-2007, 04:11 PM
We run the black one in a mustang 15psi boost 500 rwhp vented to intake with no problem

AllSpeedAndy
12-21-2007, 06:21 AM
We've run both the small "street" and the "race" by-pass valves on alot of different set ups.

The only issue that I ran across with the small valve was that even on a D1sc making 16 #'s it was not venting enough boost pressure. Or venting quick enough...when it would open the blower would shutter similar to the sound a turbo makes when bounced of the gate...this caused some stumbling problems in on-off-on the gas situations (pedaling) Especially on injected cars with a mass air meter.

This is were the red or bigger race valve helped...it dumps a lot of friggen boost pressure and fast and more responsive...the only thing is, from the front of car or next to it while driving it sounds like a jet engine when not in boost...some people like it, some don't

JamesJ
12-21-2007, 12:23 PM
Thanks for the reply guys...

Helps to what others have say...

surreyboy
12-21-2007, 12:25 PM
like someone said if its a mass air car you cant vent the air to the atmosphere after the meter.Or your going to run rich once it vents.

Blown353
12-21-2007, 03:01 PM
A single standard Pro-Flo bypass was not enough for my D1SC @ 15psi. I would get light compressor surge after snapping the throttle shut at 4500+ rpm. I did not have this problem when I was non-intercooled, but once I added the intercooler and had a much larger volume of compressed air to "dump" when closing the throttle the single Pro-Flo was not enough.

I now run 2 Pro-Flo valves. No more surge problems and it's *MUCH* quieter than the Race bypass valve which is really, really noisy.