I don't know, Bob. I was prepared to believe you using the reliable Hoover turbocharger vacuum system - but, now that you tell me it was a Kirby, well...... {:>)
IF only increasing the air flow volume or velocity would push significantly more air into the same displacement area all of these claims would be more believable. But, the only way I am aware to mechanically increase the amount of air in the same volume is to increase its density (which results in higher pressure of course) by in effect compressing it. When you have a pump doing this it has to be fast and has to be able to resist the back flow from the higher pressure area. Positive displacement pumps such as the roots roller or the screw types can do this at slower speeds but generally with less efficiency and require a bit more power. The centrifugal pump generally has to spin faster and requires precision impeller blades and diffusers.
You can make more power chemically as George suggested using Nitrous Oxide and perhaps other drag racer type fuels containing oxiders, but just sending a stream of higher velocity air into the intake at the rates mentioned simply won't do it.
You might gain a small amount due to the kinetic energy (Dynamic pressure) of the fast flowing air converting to a static pressure increase, but not anything approach several inches. If all the kinetic energy of a 350 mph wind stream were converted to static pressure you would get around 2 psi of pressure increase. It would, of course, have to also have to be of sufficient airflow volume (CFM) to stuff a manifold worth of air to a 2 psi increase - all the time the engine is sucking down the pressure in the manifold.
I won't say it can not be done, but I don't see how
Ed
----- Original Message -----
Sent: Friday, December 21, 2007 10:30 AM
Subject: [FlyRotary] Re: superchargers electric
OOPs...it was a Kirby vacuum cleaner.
bm
-----Original Message-----
From: bmears9413@aol.com
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Fri, 21 Dec 2007 8:29 am
Subject: [FlyRotary] Re: superchargers electric
ED,
I built and electric supercharger back in 1980 that would produce about 3 lbs. of boost. It was built from a Hoover vacuum cleaner. Even then the high output motor was over a hundred bucks. I wired it direct to the alternator (back the they were external volt regs) and ran it off 110 volts. Still have it. Would make a significant difference in the performance of a GLC!
Well, I have already confessed my skepticism - however, its really hard to say. One thing in their favor, they appear to be using a centrifugal pump with a scroll diffuser very similar to that on a turbo charger. Meaning that if indeed they can spin it fast enough it should work. Now one of the individuals on their forum indicated they measured its spin at 25000 rpm. That's a bit slow for a turbocharger but, it may indeed be enough to produce some boost.
We all know that motors and electric devices have made some major improvements in the last decade or so, but still a 1 1/2 HP electric motor just seems a bit on the large size physically and what really bothers me is no specifications on their web site. Hard to assess and/or refute data you don't have {:>).
But, what really bothers me is I just don't see how you could even manufacture the scroll housing and compressor blades much less a 1 - 1 1/2HP electric motor and sell it for $99.00 - even if made in China. I really want to believe - but, its sure is hard to find any data to help that belief along {:>).
I guess IF I really thought it was credible, I would have my $99.00 check in the mail and I don't.
Ed
----- Original Message -----
Sent: Thursday, December 20, 2007 1:22 PM
Subject: [FlyRotary] superchargers electric
Ed, this thread is starting to look like the electric water pump thread that can't work. I just have a feeling that your inquisitive mind is going to go somewhere with this one. JohnD