electric supercharger

Does anyone have experience with an electric supercharger?

The ebay ones?

They're about as good as duct taping a hair dryer to your intake.

In reply to BoxheadTim:

No, thinking a lot more professional with about a 2 hp motor and serious controller for amps (maybe golf cart).

I think that about 75% of the power (increase) comes from the first few pounds of boost and I want to play with running pressure up before opening the throttle, thus no turbo lag or parasite drag at high rpm.

Actually you'll get parasitic drag via the alternator. That's probably less efficient than running an S/C directly off the engine.

In reply to BoostedBrandon: Thanks Brandon...probably have an 18vdc portable that gets close? These (like above) are fairly well developed blowers (efficiency). Seen one 12vdc?

I did a basic thermodynamics analysis of this when we put the supercharger on the Wreck Racing miata. It can easily take 30-50 hp to turn a supercharger even at low boost on an engine with modest displacement (4.0 L). I have only ever seen one electric supercharger that would make actual power - it was turned by three starter motors:

BoxheadTim wrote: Actually you'll get parasitic drag via the alternator. That's probably less efficient than running an S/C directly off the engine.

This might be true as well. There are obvious advantages to have an electrically driven unit in terms of off-peak performance though.

In reply to JohnyHachi6:

Thanks JohnyHachi. That's some HP (amps) in that setup. Also high pressure.

Have you looked into the difference of vacume vs. low positive pressure or ever seen charts that have apples to apples comparisons?

Uhhhh, no.

direct drive is the most efficient supercharger. period, end of story. 1st and 2nd laws of thermo.

If you are wanting something to give more boost on low end without all the parasitic drag on the top end, that is the only situation I can think of this would even be a thought, but there are other ways to flatten a power curve.

In reply to Flight Service:

I'm sure your right for most pure power applications FS. But I'm willing to experiment. Brandon's blower is more in my price range.

In reply to Toby:

That leaf blower probably won't even make 1PSI at the CFM the engine needs.

If you want economy, start combing the junkyards for a used supercharger and rebuild it. You'll be more budget friendly using proven technology. The manufacturers don't pay their engineers all that money for nothing.

Shawn

I didn't believe it at first but Hot Rod put two gas leaf blowers on a Corvette chassis and according to the dyno graphs it worked.

Ojala wrote: I didn't believe it at first but Hot Rod put two gas leaf blowers on a Corvette chassis and according to the dyno graphs it worked.

Thus why I hotlinked a leaf blower.

Trans_Maro wrote: If you want economy, start combing the junkyards for a used supercharger and rebuild it. You'll be more budget friendly using proven technology. The manufacturers don't pay their engineers all that money for nothing.

Or I'll sell him the Eaton off a GM 3800 I have for $50 and he can rebuild it.

Ojala wrote: I didn't believe it at first but Hot Rod put two gas leaf blowers on a Corvette chassis and according to the dyno graphs it worked.

IIRC they made a little over 1psi of boost and picked up 25whp on that corvette with the twin leaf blowers

If any of this stuff worked, we wouldn't have V8 motors.

IMO.

DavidinDurango wrote: If any of this stuff worked, we wouldn't have V8 motors. IMO.

yes we would- and they'd have electric superchargers on them.

sometime in the last few months, i saw a youtube video of an install of an ebay electric supercharger on something. i think it lost power. then they put a couple of gas powered leaf blowers on and gained a little power.

I understand that direct drive would be most efficient over a long period of time, but what if you just wanted to be able to boost for say a minute at a time Like on an autox course. I'm sure you could get a battery that would give you a minute of use without having to be charged by the alternator for no parasitic loss during your run...

Why not. Starter motor and then a belt drive to the roots type pully? You could pick up some gearing with different pully sizes.

That's bleeding edge stuff. It may be theoretically possible but nothing you can get off the shelf is any good. You'll need a Serious Horsepower electric motor (maybe 25-40hp) and you'll need to upgrade the car's electrical system to be able to power it. An then you're going engine power -> alternator -> high-amp cable -> motor -> boost instead of engine power -> boost...

mw wrote: I understand that direct drive would be most efficient over a long period of time, but what if you just wanted to be able to boost for say a minute at a time Like on an autox course. I'm sure you could get a battery that would give you a minute of use without having to be charged by the alternator for no parasitic loss during your run...

What JohnyHachi6 posted is exactly that.

Check this out: http://www.turbomagazine.com/tech/0406tur_knight_turbo_electric_supercharger/viewall.html

Keep in mind that a lot of traditional superchargers have electromagnetic clutches on them that would make the same thing possible without the loss of efficiency while running...

A friend tried one on his ice racer.

He felt that it did help at part throttle but restricted the intake at full throttle, which reduced his top end.

I was thinking a supercharger for a Nissan Leaf.