Electric supercharger for efficiency?

[California98Civic]

Originally Posted by Ecky

I'm under the impression you'd get more power increase from an e-supercharger but in terms of total efficiency, it would be less than a straight e-assist.

I bet you are right. And an eAssist would be easier, if we go back to thinking just about practical EM bolt-on ideas. I have two vacant spots on my crank pulley from the delete of AC and PS. I could leave the stock alternator in place and add a small electric motor. The belts are prolly smaller than ideal but hopefully still useful with a properly small motor. That motor could maybe propel me around parking lots or extend glides. But that's not really the topic of this daydream concept general efficiency discussion.

[Ecky]

Originally Posted by California98Civic

I bet you are right. And an eAssist would be easier, if we go back to thinking just about practical EM bolt-on ideas. I have two vacant spots on my crank pulley from the delete of AC and PS. I could leave the stock alternator in place and add a small electric motor. The belts are prolly smaller than ideal but hopefully still useful with a properly small motor. That motor could maybe propel me around parking lots or extend glides. But that's not really the topic of this daydream concept general efficiency discussion.

As a bolt-on solution for e-assist, you might choose to change the cam timing so it functions in the Atkinson cycle. A net gain in thermodynamic efficiency, increased engine load, and you still maintain adequate power down low. I could see a huge gain here for relatively little cost.

[hayden55]

Audi should be coming out with theirs this year. And ford will here in a bit as well. Basically the entire goal of echargers is to spool up faster to mimick a larger engine and allow a smaller engine to save on fuel (similar to how a hybrid uses its electric motors to allow a smaller engine).

[teoman]

https://youtu.be/G8XT00GpKuE

This guy is doing experiments.

[California98Civic]

Originally Posted by teoman

https://youtu.be/G8XT00GpKuE

This guy is doing experiments.

There is the highly impractical again. He never really gets all that much boost for at the power he is consuming.

[niky]

Too big a compressor wheel.

The Thomas Knight kit made 10 psi.

[pgfpro]

Originally Posted by Ecky

To be fair, there are still energy losses associated. Intercoolers exist for that reason. They add exhaust restriction and there's also added friction, but I imagine it to be a net gain.

The losses associated with todays turbos is very little at lower boost. On my last setup the turbo improved the engine efficiency of my engine a ton, but to improve FE I had to run it in lean burn do to air mass increasing.


I still think you can use a turbo compound system on a downside engine like I did on my 2.0L. and be more efficient then an electric assist setup?

[ProDigit]

An electric supercharger or turbo would generally not work, unless,
Mercedes has been doing some research...

Instead of a Turbo compressing incoming air, Mercedes equipped their car exhaust with turbo-like turbines; powering a small generator; feeding a battery, that goes straight to an electric motor.

You could even do without the battery, and just install an electric motor to one of the rear wheels, and directly connect it to the generator powered by the exhaust turbine.
It would only be bad if you'd be pressing the brake at the same time as the accelerator.

Anyway, you'd be surpassing 50% engine efficiency like that, or add about 30% of MPG.

If you do install a battery pack, or supercapacitor pack, you could harvest kinetic energy on one wheel (if engineered well).


The simpler solution is use one of those turbo exhaust blades and electric generator, to power an electric supercharger. The exhaust would be making a few HP in most cases.


Just adding a 12V supercharger would probably increase HP by 1% or less, and isn't worth it.

[ProDigit]

Originally Posted by teoman

https://youtu.be/G8XT00GpKuE

This guy is doing experiments.

Take a look a this:

https://www.youtube.com/watch?v=cbGWgvJN1_8

[cRiPpLe_rOoStEr]

The most realistic approach by now is Volvo's PowerPulse system fitted to some of its Diesel engines, which resembles the air-starters fitted to most commercial jet aircraft. But anyway, if I would ever consider enabling electric drive on a turbocharger, I'd be mostly inclined to have some sort of starter-generator coupled to the central section of the shaft like it's done with the generators and other accessories of a modern aircraft engine.