RCinXS

The Synapse BOV is huge, at about 9 inches long and 4 inches in diameter.

I'm planning the plumbing out, so the questions are:

Is it better to route a Synapse BOV as a vent-to-atmosphere BOV or as a re-circulating diverter valve?

And if routing it as a re-circulating diverter valve, which would release the air to incoming side of the Supercharger, would it be better to install it before the Inter Cooler? OR after the Inter Cooler to push a bit of colder air into the Supercharger at idle?

As a 4th Option: Vent the front of the Supercharger case and release some cold air into that, to cool the bearings at idle?

Opinions?

blown 87

On a blower you would vent to atmosphere, or you will get surge in many cases.

blown 87

And the air coming out will be hot, not cold.

hans14914

Depends on where you are metering the air. You can not use a vent to atmosphere downstream of a MAF sensor. If you are planning on using it in recirculation mode, I would reccomend using the Synapse diverter valve instead. It is much more compact, so it would be much easier to mount.

I looked at the Synapse stuff a while ago when I needed an unusual fuel pressure regulator. I guess they had some issues with the technology back then, and have since stopped selling fuel related products. I hadnt looked into the product offerings since then - any reason you are using this unit over a standard "Bosch style" recirculation valve? Just curious.

RCinXS

Agreed. The air coming out of the Blower is hot, which is why the questions have been posed.

Re-circulating the hot air back ito the blower didn't seem like a great choice to me, though this is the way many others are plumbing it.

So I started thinking about the following:

Top of the Spider temperature on a Summers day is about 65 degrees.

62 - 63 degrees at the Intercooler.

The heat exchanger really does do a nice job.

These are the temperatures of the Metal.

There are only 12 inches between the Intercooler and the TB air guide, so if the BOV is mounted between them, the air Blown off by the BOV will be cold, absolutely.

Relative to the ambient temperature of the engine bay, very cold.

How much of the cold air will be drawn by, or pushed to, the supercharger after the initial pressure release is an unknown value.

But "X" amount of cold air will flow through the valve to wherever it has been routed, as long as the valve is open.

I can measure the actual flow with a meter once the valve has been mounted, but not before.

Since the valve is only open at idle, it can either move hot air or Cold air (depending where you mount it) when the car is basically standing still.

So I thought why not steal a little of the cold air and do something with it.

RCinXS

Hans,

Yes I have a Bosch style valve. Doesn't seem to work very well. So I thought I would upgrade during the winter project phase.

RCinXS

MAP sensor is conected to the rear of the Plenum.

blown 87

True on the location of the MAF, I have seen one with the MAF right after the blower, it did not work very well.

Lizard928

hmmm, tried to respond earlier, doesnt seem to have made it in.

It doesnt matter much if you vent to atmosphere, or re-circ. If you recirc it will be significantly quieter though. So if that is at all important for you, then consider that.

blown 87

What kind of intercooler are you using? ice water to air, if not that air is going to be a lot hotter than that if it has been used a bit.
My air to air cooler is huge and the blow off air is very hot after a hard run.

RCinXS

Greg

Iced Windshield Washer Fluid into the pump.
Pumped to the Heat Exchanger.
From the Heat Exchanger to the Water to Air Intercooler.
CO2 to the 3 gallon reservoir when needed.

Believe me, it's cold.

Bosch Blow off valve installed just after the blower now. Yes, air is hot, coming from the BOV right into the engine bay.

But if I put it in just after the Intercooler (before the Throttle body, Plenum and MAP sensor) the blow off will be cold air.

Just thinking about the new plumbing at the moment. It would be nice to take some of what would be cold Blow Off air and do something with it at IDLE.

Really leaning towards venting it into the front of the blower casing (2 vents, 1 in, 1 out), to cool off the Blower bearings and belt a bit.

blown 87

Yea, that would make it cold.

RCinXS

I've seen somebody running an electric fan attached to a tube blowing air through the blower using the same concept of 1 vent in and 1 vent out. He was convinced that it did help in cooling the bearings, etc.

It looked for all the world like a pre manufactured product. Wish I would have asked where he had gotten it.

RCinXS

Then I'd have forced cold air induction to the blower bearings at idle.

Hmm is that really such a silly idea???

RCinXS

Would that make it a blown blower???