I don't know much about these....
I think they are only used on turbos but I know very little.

My question is....

Can something like a progressive boost controller be used with a supercharger (I have the Mag)? Or maybe something to fool the vacuum switch to keep boost off until it's wanted.

I get no traction in first gear, none for most of second unless I work the sh#t out of the clutch/throttle, and if I hit the right spot in the powerband in third I light up the tires as well.

I'd like to see something where I can run boost progressively through the gears starting with none in first, building in second, and full tilt in third, or customized how anyone else may want it.

Even if there had to be a small switch I could mount on the shifter.

If not progressively, could the be done in an all off/all on way?

Sorry if this is stupid or pie in the sky...no flames please!!!!

 

Doesn't the maggie have some kind of custom BOV? Could that be modified to work with a solenoid that would be controllable?

I haven't installed my maggie yet but I'm very interested in this subject!

 

Mark, the only dumb question is the one you don't ask!
Yes there is a way to control the boost progressively, back in the 70's we used a lot of vacuum restrictors in line for emissions, if one were used in line with your vacuum switch. It would have to be reversed so it would bleed vacuum slowly off the switch your boost would be progressive.
You would have to do some experimentation to find the right rate but I bet it could be done.

 

Sweet....thanks for the info...now to start asking around for shops that can do this. Any ideas????

 

ttt...anyone with additional information or where to go for some advice?

 

rather than de-tuning the blower, just improve the traction. Wasn't the added power the reason you installed the maggie?

 

Well, it can be done, but it will require quite a bit of tinkering. There have been guys who have done it in the past with success on other cars. There have also been a few vette guys who have used a similar approach to limit boost.

A boost controller does its thing on a turbo car by controlling the waste gate. A waste gate is a valve/gate that diverts exhaust gasses away from the turbo housing. This causes the turbine and compressor wheel to slow down, which obviously reduces boost on the pressure side.

A waste gate is designed to open at a certain boost pressure and it uses a line from the pressure side and a spring to control when the valve opens. The electronics of a boost controller actually control a solenoid that sits in the middle of the pressure line before the waste gate and attempts to fake out the waste gate by not letting it see the actual boost that is being created in the pressure side of the tubing. The solenoid only allow for so much boost control, because the spring in the waste gate will have a limit on how much boost it can hold. I think you can generally get close to 2x the wastegate spring with a boost controller, so a 10psi spring would let you dial in 10-20psi of boost.

Ok, that covers how an EBC (Electronic boost controller) works on a turbo car. Now on to a CF blower car.

A CF blower obviously does not have a waste gate to control the compressor wheel, so you have to use a valve to blow off air that has already been moved by the blower. Another option would be to put a TB on the blower inlet and restrict the air going into the blower and then control that TB with electronics.

The simple setup that I have seen working consisted of:
- A boost controller
- 2 blow off valves that use a push mechanism and have dual ports (one that closes the valve with boost and one that opens the valve in over boost) I think the vortech valve works this way. There are also others, but I can't remember who makes them.

The boost controller is setup to control the pressure going to the overboost port of the valve. The boost controller opens the solenoid when the desired boost is obtained and that pressure is then used to open the blow off valve.

Your BOVs would have two lines going to them. One going from the intake manifold to the BOVs. The other going from the blower outlet area to the BOVs, with the EBC solenoid in the middle.

I was going to play with this myself at one point, but I determined that controlling the throttle was a much cheaper solution.

 

Quick,

What would happen on a CF blower if you had a BOV with two ports--one which operated normally (no vacum = closed valve / boost) and the other had an electric solenoid that would only open manually when a switch was activated in the car. That way, we could just put the BOV in bypass for the first one or two gears. I imagine that this would also play havoc on the fueling though.

 

Quick,
Very interesting process. Why do you need 2 BOVs. Would an EBC work with the Vortech BOV connected to the vac port? Does the EBC generate pressure on it own in the over boost scenario? I just don't understand how the EBC functions. I'm looking at this solution to control over boost primarily. If this worked, how would it effect the tune?

I hate to monkey with a new setup that I don't fully understand.

 

I think you need 2 BOVs because one cannot flow enough air to control boost (you have to dump quite a bit of air for this to work). You might be able to drop it 2psi or so with one valve, but two would give you more control.

The EBC does not generate pressure on its own. It simply controls a solenoid that sits in the middle of a line that gets pressure from the blower/turbo outlet.

It would most likely make the car run richer when you limited boost. It really depends on what your PE vs RPM table looks like. If it has a pretty flat EQ # across the RPM range then your tune would not change at all since the MAF would be in full control.

 

Unlike a turbo, the SC is a great compressor, whereas the turbo can flow more air. Bleeding off just a small amount of air would dramatically reduce boost and hopefully not stress the head unit. It would be nice to max out at a controlled 6-7psi rather than 10psi with a P1SC.
That is more of a question than a statement as I can only assume a lot here.

 

Wow, all I was suggesting was a vacuum line restrictor to delay the closing of the compresser dump valve.
What we really have is not a BOV, it's a valve that remains open as long as you have a certain level of manifold vacuum. The loss of vacuum causes it to close allowing the compresser to boost the intake.
The restrictiors I am refering to were used in the mid to late 70's usually between the vacuum source and the vacuum advance on the distributer.
They were a small plastic can with a nipple on each end and were dirictional in flow and were color coded for rate.
One of these installed in the vacuum line going to the dump valve would delay the closing of it.
Your boost would just come in later but still achieve max. boost at the desired RPM. Since the restriction only works in 1 direction and is free flowing in the other it will allow the valve to open to dump when you lift your foot.
As far as sources are concerned I would look at places that manufacture replacement parts for classic cars or older auto parts stores.
Another method for the ATI units, if I remember correctly there is an adjustment controlling the load of the spring, Maggie owners I'm not sure but it's most likley a sealed unit like my GTP is. But as ingenius as some people are on this forum I would bet someone could fabricate something that would work.