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Discussion Starter #1
Need some help with this. I am trying to make a maybe supercharger out of a variable speed motor, fan, and case. The problem is how to control the speed of the motor. Do I use an input from the MAP, TPS, or the tach. The motor has a controller to change the voltage for more or less speed. The motor has a range of 2000 to 20,000 RPM. I think this would be enough to produce at least a few pounds of boost. Any and all help would be greatly appreciated.

Thanks, Xstatic
 

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Why can't you just let the fan motor run at 1/2 speed until the throttle is open more than 1/2? Then just let the fan motor run at full speed and just control the enging by opening or closing the butterflys. If we're only talking about 2-4 pounds of boost you could also have the fan motor at full speed all the time and control the engine thru the fuel injection butterflys.

Just a thought.

John
 

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You have a lot more than that to worry about. MagnaChargers is still trying to get their supercharger to work with the VTX. Been working on the ECU and getting the charger to run without killing the engine. If you figure it out, then I'd say you have a customer in MagnaChargers. Good luck 8)
 
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No easy way to adjust the fan speed, kinda works like a R/C car more voltage to the motor = more speed. The controller needs to mounted in a hidden spot, no easy access. Trying to get more boost with more throttle on demand.
 
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Would this be any different than adding a turbo? I was not aware that any mods would be required to the ECU.
 

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Good Luck... :lol: :roll:
 

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Well yea you have to make the sc spool up/down in accordance to the engine speed and that has to match exactly with the fuel injector pulses. You can't have a single speed motor pumping air in like you were travelling 75mph when your idling. Turbo's doesn't have to because it goes off of the exhaust gas speed, when you open the throttle the faster the gasses come out, the faster the turbine spools. You only need a PowerCommander to help manage the fuel flow. 8)
 

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Tie the fan output to the throttle position sensor, or to the throttle cable.
 

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Everything I've ever read about electric superchargers says they are a waste of time. The motor you have may be able to spin up to 20,000 rpms, but that's in a no/low load situation. Things will change drastically once it starts trying to compress air instead of just moving it. It will require not only a speed controller (voltage), but you'll need more torque (amps) as the speed increases also. That's really the easy part. The charging system required to run one constantly is the hard part, and the X's charging system isn't up to the task. It'd take some kind of alternative charging system...some kind of generator and a big one at that.

I'm not saying it hasn't been done though. I've heard of electric supercharging systems for smaller automobile engines. But some of the HP gains are eaten up by extra weight from the batteries to run it. And, once the batteries are dead you don't have any more boost.

I wish you the best of luck in your endeavor, though. If you figure it out let us know.
 

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Tappers thinking on the same lines as me. You mentioned it being an R/C car motor or similar? I used to race at national level with these cars many years ago. Why not get yourself a cheap, second hand, digitally proportional 2 channel radio transmitter and receiver set-up, with a variable electronic speed controller. you would have to find a way to link one of the controllers in the transmitter ( the joysticks) to the throttle action of the bike (and you'd also have to remove the joystick from the bulky transmitter box) if you could do this you'd achieve what you're wanting - more throttle = more voltage to motor = faster fan! Hope you get what I'm on about!!! Its so easy to picture in the minds eye but yet so hard to put into words! After all that I still think you'd have an issue with fueling though.
 
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I would suggest a pressur sensor in the output side of the charger so that the boost would remain constant regardless of the engine speed (you could also scale it so that it was non-linear to get more boost at higher rpm). Tie the output to the controller and you can make it a closed loop system that can be adjusted.

Lonewolf
 

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Hey, I have a 12 volt hair dryer you can use!
You will have to install an outlet and plug it in at the correct time to make the boost come in !
Just kidding, I'm really bored need to go RIDING! :lol:
 

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Smarmy said:
I found this formula for power required from a blower here (post by NoGo almost halfway down)
http://www.ls1tech.com/forums/showthread.php?t=155899

Assuming 5000 rpm, 5psi boost & 60% efficiency (probably way too high unless you use some kind of postive displacement blower)
HP = {(CFM * Boost) / 229} / Efficiency
HP = {(160cfm * 5psi) / 229} / .6
HP = 5.8hp

A 6 hp electric motor is probably going to weigh 80 lbs (not even counting the blower) & draw 450 watts. Since the alternator only put out 400 watts, that's going to be a problem too.
actually a 6hp motor is 4500 watts. 1 HP = 746 watts
 

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not only is it going to take a huge generator, you are going to need some big wire as you will be pulling 375amps!
 

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Smarmy said:
I found this formula for power required from a blower here (post by NoGo almost halfway down)
http://www.ls1tech.com/forums/showthread.php?t=155899

Assuming 5000 rpm, 5psi boost & 60% efficiency (probably way too high unless you use some kind of postive displacement blower)
HP = {(CFM * Boost) / 229} / Efficiency
HP = {(160cfm * 5psi) / 229} / .6
HP = 5.8hp

A 6 hp electric motor is probably going to weigh 80 lbs (not even counting the blower) & draw 4500 watts. Since the alternator only put out 400 watts, that's going to be a problem too.
Finally... There is a reason this hasn't been done before. :? :roll:

60% efficiency is way too high.
 
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