This is something many oems are working on. Everyone wants turbos as they allow you to capture waste heat from the exhaust. However lag has always been the problem here.
IIRC BMW's system uses an electric motor to spool the turbo until there is enough exhaust gas flow to power the turbine. This is going to be a good stopgap measure until thermo-electric generators become cheaper and more efficient. If we could capture even half of the heat which is current wasted out the exhaust and radiator we could double fuel economy.
Lots of people want to think the ICE is dead but the truth is we have a long way to go before that happens.

Need MOAR POWER!!!!

Im going to go out on a limb and say a full reconstruction of OEM voltage (a la 24-48 volts) is a little ways off in the future. Think of the poor aftermarket parts suppliers lol and theres just sooo many places to lose energy in a system like this its crazy!

I suppose they could make it like an aircraft (which btw have 28 volt electrical systems) and have the starter also be be a generator when required to run the turbo at high throttle settings... :iono: I'm more than willing to see it in action

KERS and "mild hybrids" are the key to making electronic turbochargers happen. Alot of racing teams already employ regenerative braking. Some are developing regenerative dampers (using voice coil and piezo tricks). Seebeck generators are only ~5% efficient at converting thermal energy to electricity, so it will be a while for that tech.

If KERS systems become faster and larger capacity, it will be simple enough to integrate an exhaust turbine generator and electric supercharger.

Storage is already getting there. Ultracapacitors (like the Maxwell units) are still pretty expensive, but the technology is there. The car audio competitors have developed some amazing systems that maintain voltage at insane current draw:
http://i651.photobucket.com/albums/u...1-32-22_96.jpg

Typically DC motors run at 90 or 180V, but you can get custom windings from most manufacturers. I'd imagine the starting circuit will stay at 12 or 24V, but the KERS systems will be stored at a higher voltage and connect via step-down transformers and a really big diode bridge.


side note: If you think the Toyota/BMW collaboration is just about making a car, you're forgetting just how many patents and R&D hours the Prius has clocked. You're also forgetting all the EfficientDynamics research that has gone into BMW's plug-in hybrid turbodiesel.

@serialk11r

This is your type of discussion, right?

you need a lot higher voltage to put out the crazy power necessary to compress massive amounts of air really quickly. current brushless motors about the size you'd want in a turbo/supercharger/nutty electric hybrid thing (like a 700 size rc heli motor) can make 6-12hp, and they weigh very little. i'd call it an eventuality at this point... just a matter of time before it's possible, then some day practical.

it makes sense that it would be best used to spool a turbo, since keeping up with the airflow demands at high rpm would require a ton of power (and generate a ton of heat).

That's one of those ideas that's so simple and yet so brilliant. I love it. :thumbup:

There's a really cool duality to this if it plays out the way I think it might.

When diesels first came out they needed a supercharger to run. Two stroke diesels with the ports in the sides of the cylinder walls didn't have the ability to create sufficient suction and keep the intake port sealed off during combustion, so they absolutely had to be force fed.

I wonder how long it'll be before they stop designing intake port head flow to ever work in a vacuum/ And I wonder what that'll do the shape of the posts.

This is a much more interesting thread than i expected. You could run an alternator off a turbo exhaust housing also. Not neccesarily as efficient as a normal turbo but would be interesting none the less.

I remember reading about a possible future WRX/STI platform.
Not hard specs, but a supposed theory.

The turbo has an electric motor matted that can engage/disengage.
At low RPM electric motor assist the turbine = reduced/no lag.
Disengages when the engine produces enough exhaust gasses itself to spool.
Thermal energy from exhaust housing is converted to charge the units separate battery.
That battery or cell is also supplied power from vehicles power supply.



Off topic below.

Above speculation plus a new light weight, smaller, AWD chassis has me excited.:happyanim:
As of now, one can only dream.:sigh:

Don't do it. Been tested don't work. There's a clip on YouTube on those electric turbo.

read
the
thread

this is not about the ebay electric turbos for sale

this is about theory and developing a future electrically powered turbo utilizing advanced battery/capacitor tech

From my experience from playing with alternators, generators, and electronics with motors. I can tell you that it is possible to do, but this application eats too much efficiency out of the system to be... efficient.

I can see a three phase AC generator being used to power a three phase electrical motor to power the turbo.

The reason that we use the mechanical TC's and SC's is that they have a high efficiency at the moment. Efficiency as in when we convert energy from one system to another we lose energy.

You know that fan motor that you put in font of your car when you dyno it? That is what I'm talking about, or very close. Yes a 120V AC motor would do the job. Now I just need a 120V alternator.

Hm... brb

Its possible but not worth it, simply due to weight(electric motor+cap/bat+drive) and other way of making more power cheaper/easier.

KERS(at least mecanical one) are use for specific usage in specific race regulation, not as efficient in the real world.

As for voltage or type of voltage, there no really link with the power an electric motor give, its mostly all about want kind of caracteristic you want from motor and how it is built(High amperage generate more heat in component(loss), so best to keep low by having higher voltage).

I think, if I would go for some crazy design(did not say its feasable) for higher power in short burst, I would start by having directly an electric motor that replace the drive shaft(weight would be low as for gravity), possible torque(due to large surface) quite high, could be use as regenerative device, since connect directly with the rear tyre, or with the engine when clutch engage, would not put more stress on the engine. And would not take any efficacy(MPG) out of the current system.

Lot's of talk about "how" it could work, but what about "how long" will it last? There will obviously be a trade off for useful time and battery / capacitor size, but what do you consider "enough" before it putters out? One lap on an auto-X course? Several laps on a big boy track? Are we only looking for a boost at low RPMs or will this also keep the turbo spool'd in between shifts (mitsu did that right?) because that'll play into how long the juice lasts.

How long would to recharge it would you find acceptable? For instance my very mild hybrid CRZ takes quite a bit longer to recharge when you compare it to the useful battery. It's (lol, sadly) a better hybrid if you switch between normal and ECO modes instead of just leaving it in ECO (eats the battery charge quick).

The efficiency could be there in a hybrid where you already have a secondary electrical system in place, and get power from regenerative breaking.

As for KERS its not just for race use anymore, new systems are making it into production cars as we speak. Porsche, and Ferrari already have production models with KERS, and Volvo, BWM, and Toyota have systems in development.