tvs 2300 help please !!

[LDM]

So where does the air that goes thru the bypass go ? Into the IM (meaning down into the cylinders) ?

Yes and no. If you open the bypass valve, yes air can flow directly down to the intake manifold. Normally when the engine is running though, air is actually flowing out from here back to the inlet of the rotors. This is because of how a Roots-style blower works. No compression takes place in the rotors at all. It is just a positive displacement pump that for every revolution of the blower takes a fixed amount of air from the inlet side of the rotors to the outlet side (intake manifold). The compression takes place in the intake manifold because the rotors are pumping more air in than the engine can consume naturally. As you keep cramming more air into a space than is leaving the space, pressure builds up. Opening the bypass valve vents this excess air back to the inlet side of the rotors so it's no longer building up boost in the manifold.

To sum it up, this picture should explain things:

I was thinking that while my TVS is busted (waiting for new parts) I could disconnect the vacuum (and plug the line) and ziptie the bypass arm so that the bypass butterfly was always open. Does that make sense ?

In your case, with the rotor not spinning, I suppose opening the bypass valve would be the best path for air to flow, just probably very restrictive (though probably not as restrictive as trying to flow through non-spinning rotors.) I'd check with the Magnacharger rep you're in contact with to see if he'd recommend doing it.

[jbak]

LDM............. thanks ! That was the best explanation I've heard as to how the rotors and bypass work. I never planned on learning so much about the Magnuson innards...LOL...

The Magnuson rep thought that..... 1) remove bypass actuator vac hose... 2) plug hose... 3) wire bypass OPEN...was a good idea.

Magnuson is going to send me a whole new top unit.

[Crazy8]

It's good to hear Magnuson is taking care of you. Seems crazy that the pins would have sheared at your power level.

[STL_G8GT]

Yes and no. If you open the bypass valve, yes air can flow directly down to the intake manifold. Normally when the engine is running though, air is actually flowing out from here back to the inlet of the rotors. This is because of how a Roots-style blower works. No compression takes place in the rotors at all. It is just a positive displacement pump that for every revolution of the blower takes a fixed amount of air from the inlet side of the rotors to the outlet side (intake manifold). The compression takes place in the intake manifold because the rotors are pumping more air in than the engine can consume naturally. As you keep cramming more air into a space than is leaving the space, pressure builds up. Opening the bypass valve vents this excess air back to the inlet side of the rotors so it's no longer building up boost in the manifold.

To sum it up, this picture should explain things:






In your case, with the rotor not spinning, I suppose opening the bypass valve would be the best path for air to flow, just probably very restrictive (though probably not as restrictive as trying to flow through non-spinning rotors.) I'd check with the Magnacharger rep you're in contact with to see if he'd recommend doing it.

That's EXACTLY how I understood it all to work!!!

[LDM]

That's EXACTLY how I understood it all to work!!!

The picture or what I wrote?

[STL_G8GT]

The picture or what I wrote?

Cmon man, the picture!

[tigercatf26]

Of topic but where did you get those covers for the valve covers? Or are they actual valve covers? They are sweet looking and would love to find a set. Any help would be great.

The bypass valve itself is internal to the blower.



The plunger looking thing is the actuator for the bypass valve.



The valve allows air to recirc back to the rotor inlet, preventing the build up of any boost. At low loads, this reduces the power needed to turn the rotors, thereby increasing efficiency. The actuator is basically a diaphragm with a spring on one side and vacuum line on the other. The valve is normally held open by the spring, but at idle and low loads the vacuum is strong enough to overcome the spring tension and open the valve. As load increases and the vacuum drops off back towards 0" Hg, the vacuum doesn't have enough force to overcome the spring and the bypass valve closes. I think I read somewhere that Maggies start closing the bypass valve around 3" Hg. Now with the bypass valve closed, pressure will build up in the intake manifold and you get boost. If for some reason the valve was stuck open, everything would spin like normal (no weird noises) but you wouldn't build any boost and thus not much power.

Since the normal resting position (at atmospheric pressure) of the valve is closed, when you start the engine and it idles, the actuator should move opening the valve. If the actuator doesn't move when you start it, that could indicate that the valve is already (stuck) open. Try watching the actuator while someone else starts the car.

[LDM]

Of topic but where did you get those covers for the valve covers? Or are they actual valve covers? They are sweet looking and would love to find a set. Any help would be great.

They're Holley LS Coil Covers. They come looking like this:
But with some trimming and paint I got what I ended up with.