anyone have a pic of the bypass valve?

[nickmpower]

???

[FATHER]

what kind of bypass, supercharger???

http://www.superchargertech.com/PARTS.html

[nickmpower]

i acatully wanted to see one installed so i could see if it would be possible to rig up something to turn it on and off

[pdxmotorhead]

With the eaton style superchargers there's really no reason to turn it on and off unless you want to disable the blower for Valet mode or something?

See the Magnesun web page they used to have pics of the blowers

The valve is pressure/vacume activated so a clippard valve in the line
or a solenoid valve will do what you want.... It works just like a wastegate physically.

Dave

[DustenT]

Lots of pics: http://180customs.net/v-web/gallery/Supercharger-Pics

and here: http://180customs.net/v-web/gallery/BMW

[FATHER]

hey dustent i win other auction in ebay for a nissan xterra supercharger for $90.00, SO I HAVE 3 OF THEM, one on the ti and two spare, or to future proyects on my friend 325, also the two ebays blower have a 3.90" pulley, so if you like to play with boost i send one to you....

[DustenT]

hey dustent i win other auction in ebay for a nissan xterra supercharger for $90.00, SO I HAVE 3 OF THEM, one on the ti and two spare, or to future proyects on my friend 325, also the two ebays blower have a 3.90" pulley, so if you like to play with boost i send one to you....

I have a 3.60" pulley so going to a 3.90" would be less boost. Maybe good for winter though.

[FATHER]

O may bad , is 2.90 not 3.90

[DustenT]

O may bad , is 2.90 not 3.90

I've been thinking about getting a thicker head gasket and trying to run some more boosti. If I ever get around too it, I'll let you know.

[nickmpower]

I still havent been able to find a good shot of it up close. do you guys think it would be possible or not?

[pdxmotorhead]

So whats the reason for wanting to shut off the bypass valve?

I'm really curious! :)

Dave

[pdxmotorhead]

I still havent been able to find a good shot of it up close. do you guys think it would be possible or not?

I just put a JPG in my photo gallery, the Aluminum part with the throttle valve thing is also built in to the later generation eaton blowers.

So you do understand that the bypass valve on the supercharger is not a wastegate? Just asking...


Dave

[FATHER]

Is not a good idea close the bypass valve....not power gain only a lot of fuel consuption

[nickmpower]

I want to be able to open it and keep it open. Then also have it go between close and open as it wants. basiclly so that you can turn it off when you dont need it on

[DustenT]

I want to be able to open it and keep it open. Then also have it go between close and open as it wants. basiclly so that you can turn it off when you dont need it on

You could setup a 2 into 1 valve to do this. When there is vaccum on the bypass valve, it's open. As vaccum approached atmospheric pressure it closes. Why would you want to bypass all the time? I see no advantage to doing this.

[pdxmotorhead]

I want to be able to open it and keep it open. Then also have it go between close and open as it wants. basiclly so that you can turn it off when you dont need it on

So the effect of this may not be what you think, the bypass air path is smaller than the stock intake. Basicly its only for light partial throttle load. Also remember the SC is re-circulating air when "on bypass" at low load so its always pumping a little whether your "on boost" or not. This is to cool the unit when its basically wind-milling with little or no load.

The design assumtion is the bypass allows an average amount of air to provide enough power to keep you at cruising speed. It doesn't have the capacity for higher rpm engine settings.

I was considering a switch like your talking about for a Valet mode so someone who either wanted to abuse or steal the car couldn't rod it.. :) Kind of a power limit switch...

All you need to do to test it is disconnect the vacume line from the valve to the intake (Its only 2" long in most cases.) and possibly clip a small pair of vice grips on the shaft so the valve is locked open. The two hose connections in the picture are where the hose usually goes.

Be sure and let us know the effect. I'd expect low power and an engine that does not want to rev to redline.

I was also considering a solenoid to lock it shut when at WOT to make sure its not leaking air by..

Dave

[nickmpower]

I thought that the bypass valve just routes the air from the supercharger back infront of the supercharger. is this right? then it should just run like an NA engine when the valve is open

[pdxmotorhead]

It would if the air path were very simple and large as the throttle body.
The bypass is between the inlet path and outlet path of the blower, the
valve opens and allows air to be drawn through without going throught he blower. But for instance my stock throttle body is 52MM The bypass valve
is < 35MM so its almost 1/2 the size therefore 1/2 the flow. The Eaton style blower is VERY efficient, if you were using a larger bypas valve your idea would work if you designed the plenum for it correctly. But there wouldn't be much point to it.

If you could give us a bit more info on your goal,,
someone could likely make a usefull suggestion :)
Do you want to get better mileage when not "needing" the boost?
Valet mode?
Wet road mode?



Dave

[FATHER]

The bypass duct is on the back of blower is open when vacuum and close without vacuum, but the blower is on motion ever, if you like you put a valve in the vacuum hose of the bypass valve if you close the the valve never have boost if you open it the bypass function normal,

[FATHER]

Ok, i find that pictures on my laptop, that is the back of my blower before i install it, so the black piece is the bypass valve of course, so the hose that i talk about is the little one between the bypass and the blower, is a vacuum hose,

[FATHER]

inside the blower, look the small size of bypass hole

[nickmpower]

It would if the air path were very simple and large as the throttle body.
The bypass is between the inlet path and outlet path of the blower, the
valve opens and allows air to be drawn through without going throught he blower. But for instance my stock throttle body is 52MM The bypass valve
is < 35MM so its almost 1/2 the size therefore 1/2 the flow. The Eaton style blower is VERY efficient, if you were using a larger bypas valve your idea would work if you designed the plenum for it correctly. But there wouldn't be much point to it.

If you could give us a bit more info on your goal,,
someone could likely make a usefull suggestion :)
Do you want to get better mileage when not "needing" the boost?
Valet mode?
Wet road mode?



Dave


I think you might be misunderstanding how it works, either that or i am.

air doesnt go through the bypass to the engine, it travels from the intake manifold behind the supercharger to the air path infront of the supercharger. So the supercharger is still compressing air its just that the manifold isnt pressurized because the bypass valve is open.

right now i am doing an NA rebuild and am just looking down the line. I would like to reduce strain on the engine and improve milage

[DustenT]

I think you might be misunderstanding how it works, either that or i am.

air doesnt go through the bypass to the engine, it travels from the intake manifold behind the supercharger to the air path infront of the supercharger. So the supercharger is still compressing air its just that the manifold isnt pressurized because the bypass valve is open.

right now i am doing an NA rebuild and am just looking down the line. I would like to reduce strain on the engine and improve milage

Absolutely correct. The supercharger isn't able to build positive pressure because the bypass valve is open whenever the throttle body is under vacuum.

BTW - It doesn't hurt to run with the bypass closed all the time. When I was originally troubleshooting my low boosting problems, Jim Goodroe from Downing Atlanta said to disconnect the bypass and drive around to see if the valve was leaking at all. I also remember someone disconnecting it for track use, but didn't see any benefit.

(Good thread guys)

[pdxmotorhead]

Quoted from the Magnesun Supercharger web page

"Why do you need a bypass valve? The best kept secret in forced induction is the little known bypass valve. This small valve, when properly installed between the supercharger and the air throttle body, allows the supercharger to become extremely efficient in terms of economy and parasitic power loss. Our M90 supercharger uses less than 1/3 of 1 HP at 60 MPH cruising. The bypass is operated by a vacuum actuator control unit that is normally closed. When vacuum is high (idle-cruising) the actuator opens the bypass valve, equalizing the vacuum pressure throughout the system. When boost is required (accelerating) the vacuum is decreased and the bypass valve instantly closes, causing pressure to increase into the cylinders. This equalized vacuum condition virtually eliminates the normal parasitic power loss of a forced induction system."

I uploaded my best shot at drawing the airflow.... :) Check my gallery.

Dave

[DustenT]

Your blue line should point the other direction. The supercharger is ALWAYS spinning, so it's always going to be sucking and pushing air into the intake manifold faster than the car can use it. With the bypass valve open, the extra air is simply allowed to escape back into the elbow, thus keeping the car out of boost. This is how it works, sorry for destroying your pic. The engine will NEVER suck air through the bypass valve, the bypass valve is only there to RELEASE air.

http://www.318ti.org/gallery/data/500/BypassValve2.JPG

[pdxmotorhead]

Ahh your right, I originally was using a bypass valve on a turbocharged engine and it worked the other way, the valve allowed the incoming air to "bypass" the turbo which
wasn't spooled up, (At least thats what my vacume gauges looked like. ) And now that I think about it that valve was WAY bigger than the supercharger one is...

Guess the old picture is worth a thousand words is true :)

I like this topic though its actually about something technical....

Dave

[DustenT]

Ahh your right, I originally was using a bypass valve on a turbocharged engine and it worked the other way, the valve allowed the incoming air to "bypass" the turbo which
wasn't spooled up, (At least thats what my vacume gauges looked like. ) And now that I think about it that valve was WAY bigger than the supercharger one is...
Dave

Yeah, a wastegate works a bit differently. The thing to remember is that since the SC runs on a belt, it's always on. Mercedes Benz uses a magnetic clutch that actually stops or slows the supercharger down, in that case they would need a much larger bypass valve to feed the motor.

[pdxmotorhead]

My car had a wastegate AND a bypass valve, the bypass valve was to let you get off the line quicker while the turbo was catching up. (T-06 on a Pinto motor <evil grin>) The bypass valve was solenoid activated based on RPM and manifold pressure. I actually had a small wet nitrous shot while on bypass which was mainly to help spool up the turbo and quicken the transition to full boost.

Dave

[DustenT]

My car had a wastegate AND a bypass valve, the bypass valve was to let you get off the line quicker while the turbo was catching up. (T-06 on a Pinto motor <evil grin>) The bypass valve was solenoid activated based on RPM and manifold pressure. I actually had a small wet nitrous shot while on bypass which was mainly to help spool up the turbo and quicken the transition to full boost.

Dave

Jeez! Sounds like a monster.

[FATHER]

So if you close your bypass valve(disconect the vacuum line) how much boost enter on the manifold at iddle speed. Also, is bad to the engine the boost at idle??? The final question... myu car run about 15psi of vacuum at idle with the ac in off, when i acelerate and then remove my foot of the pedal the gauge of vacuum/boost go to 20/25 vacuum and slowy back to 15, thats is normal??? by the way tha car run super fine,clean idle and fast acceleration

[pdxmotorhead]

That sounds normal to me, even the turbo car I'm currently working on does that. Seems like the throttle dropping shut causes a vacume surge in the intake but its harmless as far as I can tell.

Dave

[pdxmotorhead]

Jeez! Sounds like a monster.

:evil: scared me every time I pulled the trigger.

The pinto was not intended to ever go that fast...
Blackrock is a truly sureal experience.....

Used to spit rear ends all over the place...
The T5 tranny didn't like it either.
We got just shy of 500 out of it on the dyno
before it spit the jack shaft out of the block,
That converted me to a true believer in crank
fire ignition...

Dave

[DustenT]

So if you close your bypass valve(disconect the vacuum line) how much boost enter on the manifold at iddle speed. Also, is bad to the engine the boost at idle??? The final question... myu car run about 15psi of vacuum at idle with the ac in off, when i acelerate and then remove my foot of the pedal the gauge of vacuum/boost go to 20/25 vacuum and slowy back to 15, thats is normal??? by the way tha car run super fine,clean idle and fast acceleration

I haven't disconnected my bypass valve, so I can't answer that question. Your vacuum sounds correct.

[FATHER]

gracias+thanks