Electric Supercharger

[user removed]

Here is a thought for y'all.

Use the electric supercharger as a means to downsize your engine. The supercharger only needs to provide bursts of power when you really need it. Cut the engine displacement in half.

Now here is the kicker. Normal engines use a throttle plate to restrict the air available to the engine. Vacuum can do a certain amount of useful work. With an electric supercharger you have the potential to use it as a generator when it is not providing boost to the engine.

Throttle restrictions to control engine speed create no energy, while the electric supercharger could provide a means of capturing energy from the same effect as a throttle plate. Control of the throttle would be by the amount of load you applied to the generation phase of the electric supercharger.

Not sure if it would be enough to provide all the electrical needs of the vehicle, but if it was combined with a small Rankine cycle power supply using exhaust heat it should be able to drive every accessory on the vehicle.

I am not an engineer so the technical calculations are beyond my capabilities, but you can't argue the fact that using available vacuum to create electrical energy, compared to normal throttle plate losses, is in fact free energy.

This would beat any other presently available supercharger or turbocharger option. Also consider that electrical power generation would be continuous, any time the engine was running, even when there was little or no manifold vacuum. That's free energy for supercharger application, at least to a certain point.

The supercharger would have to be a positive displacement design, unlike the one shown in this thread.

Regards
Mech

[TomO]

Now here's something to wrap your brain around:
The VX motor in stock form flows 134.45 CFM at 6000RPM.
Even though the Bilge Aerator fans (4") will flow 250CFM (on a good day) and some of the model aircraft "Jet Turbine" Engines will flow 300CFM, that is still an improvement over the CFM of the VX motor.

BTW: the VX motor flows about 50CFM cruising on the highway at 2200RPM.

Since the VX uses a MAP system and doesn't actually know the amount of air coming into the system (it calculates it based on known VE and by what the O2 sees), it might be possible to use a fan like this to eek a little more power for accelerating or leaning out even more during highway cruising (althought the ECU will compensate for the air during cruising eventually).

[Christ]

Mech - I don't think the Fan could produce a fast enough response, honestly, to replace the throttle blade. A fan's blades would be the most restrictive when spinning fast, I think... slowing them down would make them least restrictive, until they're finally stopped, which would be the quintessential "full throttle" of the system. The issue with that scenario would be getting the fan blades moving again... I think you'd want the system to default to throttle closed, wouldn't you?

TomO - You could run the MAP on a reference line that takes a reading from a pre-charged section of the intake system, but you'd have to put the charger behind the throttle body. It wouldn't be altogether difficult to do, though, since you can remove the TB and add a flanged pipe w/ the aerator in between the flanges, then relocate the MAP to just before the aerator, where it would still create a "false" vacuum.

While you may be correct for the figures from a VX engine, and even other engines, the fact still remains that the additional airflow causes more electrical load (10A at 12VDC is 120 Watts) and the whole setup was originally designed (and is still being touted) for more power, not the ability to cruise lean.

[TomO]

Originally Posted by Christ

TomO - You could run the MAP on a reference line that takes a reading from a pre-charged section of the intake system, but you'd have to put the charger behind the throttle body. It wouldn't be altogether difficult to do, though, since you can remove the TB and add a flanged pipe w/ the aerator in between the flanges, then relocate the MAP to just before the aerator, where it would still create a "false" vacuum.

This is tempting... I might just have to pick up a bilge fan on the cheap from Fleet Farm and play with it.

Originally Posted by Christ

While you may be correct for the figures from a VX engine, and even other engines, the fact still remains that the additional airflow causes more electrical load (10A at 12VDC is 120 Watts) and the whole setup was originally designed (and is still being touted) for more power, not the ability to cruise lean.

I forgot to mention that the system would have to have it's own deep cycle sitting in the trunk so as to not load down the alternator, sorry. I might have a spare YellowTop Optima to play around with and try messing around with some form of this system. Time for the thinking cap!

[solarguy]

Anybody have a price on this thing?

I doubt it would give you any more FE improvements than, say, bolting a big honking alternator on your car and doing a mild do-it-yourself hybrid. It's a little more complicated than it sounds, but doable.

Finest regards,

troy

[user removed]

It would require a positive displacement supercharger that used no reciprocating parts and had super lightweight components.

A fan won't do the job. It might work with a rotary vane pump. Variable displacement would work even better. On the same shaft add the steam engine driven by exhaust gas residual heat.

Both of those energy sources are from the same energy that is normally wasted in a conventional setup. BMW was working on a steam powered accessory drive system that used exhaust heat. They claimed a 15% mileage improvement.

67% (EPA figures) heat energy losses in a typical passenger car would provide a lot of power for the initial acceleration to reduce the dramatic amount of fuel lost in those circumstances.

Additional electrical loads could be compensated for by increasing the alternator charging load on any DFCO event, which would save friction brakes.

I doubt any forced induction will make much of a difference in mileage, unless you had a smaller displacement engine. Ford is going that route with their eco-boost engines, if I understand their developments correctly.

Take the average pickup truck, SUV sized vehicle and use a 2.5 liter diesel engine. Maybe even 2 liter. Get it to produce 200 HP and good torque when you really need it, but also give you great higher load BSFC cruise capability at highway speeds.

I think that is the way they will get those full sized vehicles up to the 30-35 MPG range.

Just thinking out loud.

regards
Mech

[roflwaffle]

Originally Posted by Daox

I understand that, but he was talking about bolt on things that help FE. At least thats the way I read it.

I gotcha. That may have to do with the test mule they're using. The 2.0T is mostly about high end power, so there are trade-offs in terms of the compressor's efficiency map. Having something that can help spool up the turbo quicker may help the engine operate (marginally) more efficiently, or maybe they're just BS'ing, since I didn't see anything about the test methodology.

[roflwaffle]

Originally Posted by Frank Lee

Erm... so put the right size turbo(s) on it, that pretty much works right? Or supercharge it. Or pick what you want- low end grunt or high end scream. Me, I don't need em both.

That's just the problem, at least from the POV of design, there is no right size turbo, or turbo(s), or even twin-charged setup. Each setup has trade-offs, be it greater max power output and poor low end power output/efficiency, decent efficiency over most of the operating range, but lower power levels, or decent power/efficiency but greater weight/complexity. All this does is possibly provide another tool for forced induction in between what's currently offered AFAIK.

[Frank Lee]

Using a blower to throttle an engine is an interesting concept...

[roflwaffle]

Just like a TC/SC, but electric!