[Scorcher]

Here comes yet another BMW first, an electric turbocharger that minimizes turbo lag and eliminates the need of a wastegate. Who's gonna miss the Turbo-whoosh?

Source

After months of speculation, BMW has reportedly patented an electronic turbocharger.
The specifics are somewhat technical, but the system uses an electric motor and a series of clutches to minimize turbo lag. When the driver steps on the accelerator, the electric motor spools up the turbo to optimize performance. Once the electric motor is no longer needed, it acts like an alternator to recharge its battery. More interestingly, when this occurs, the motor prevents the turbo from spinning too fast which eliminates the need for a traditional wastegate.
It remains unclear when BMW will introduce the technology, but rumors have suggested an electric turbo was under consideration for the next-generation M3.

[vina]

^^^^ I think turbo-lag has too dimensions - the first everyone talks about is that unless the engine is already running at some RPM, the turbocharger doesn't even start spooling as there is not enough exhaust gas (and energy in the exhaust) to turn it.

The second, and often neglected part, is that even after engine has attained "sufficient rpm" the turbo will take time to spool up and spin, and the air flow will then take time to stabilise and build pressure.


I think the technique being talked about will help the delay in initially spinning the turbo, but will probably not help the usual problem people complain about - no turbo at low rpm. Otherwise the technique is basically a turbocharger-supercharger combo.

As far as introduction in a real product is concerned, getting a patent doesn't even mean that the company internally considers it a serious technique, let alone something worthy of a product.

[pranavt]

Originally Posted by vina

^^^^ I think turbo-lag has too dimensions - the first everyone talks about is that unless the engine is already running at some RPM, the turbocharger doesn't even start spooling as there is not enough exhaust gas (and energy in the exhaust) to turn it.

The second, and often neglected part, is that even after engine has attained "sufficient rpm" the turbo will take time to spool up and spin, and the air flow will then take time to stabilise and build pressure.


I think the technique being talked about will help the delay in initially spinning the turbo, but will probably not help the usual problem people complain about - no turbo at low rpm. Otherwise the technique is basically a turbocharger-supercharger combo.

As far as introduction in a real product is concerned, getting a patent doesn't even mean that the company internally considers it a serious technique, let alone something worthy of a product.

I think it will solve the problem of not having any boost at low rpm. The turbo is being driven by a seperate motor whose purpose is to just spool the turbo. However, the implementation leaves a little to be desired. An ideal system would be where the motor would keep spinning the turbo as long as it wasn't being spun by the exhaust. With an open charge pipe, the compressor-side gas would just be let out without going into the intake. The moment the driver put the foot down, the BOV would close and you'd have instant boost at all RPMs.

Either ways, what BMW did here has already been done by many smart folks, one of them being this guy.

Nick Mann's Mannic Beattie hillclimb car - YouTube

He used a helicopter engine spinning at a specific RPM to spool the turbo, instead of an electric motor.

[SirAlec]

Heard of similar thing called Surbo long ago. It was made in china and some dealer in delhi were selling it.

[Sutripta]

Wonder what the patent is for. It cannot be for the idea of using an electric motor as auxiliary drive. Maybe for using it as a boost regulator/ governor.

Regards
Sutripta

[dhanushs]

Originally Posted by Sutripta

Wonder what the patent is for. It cannot be for the idea of using an electric motor as auxiliary drive.

Sutripta Sir,

Are there any production vehicles with electric motor to power the turbo?.

Might be the boost regulator/ governor too, but then, isnt it a by-product?.

- Dhanush

[dot]

Originally Posted by Sutripta

Wonder what the patent is for. It cannot be for the idea of using an electric motor as auxiliary drive. Maybe for using it as a boost regulator/ governor.

Regards
Sutripta

As you know, many times patents are used for blocking others to enter rather than putting into practice by oneself.

[srishiva]

Dont know what all is becoming patentable. A supercharger used the engine power, now you use battery power.
Hybrids are using battery power for AC and stuff, wonder if they patented that.

[pranavt]

Originally Posted by SirAlec

Heard of similar thing called Surbo long ago. It was made in china and some dealer in delhi were selling it.

Please don't confuse it with that trash. The electric/conventional motor is used to spin a real turbo which does cause forced induction of air. The Surbo/Turbonator/XYZ is a stupid fan in the intake pipe, nothing more.

[vina]

Originally Posted by Sutripta

Wonder what the patent is for. It cannot be for the idea of using an electric motor as auxiliary drive. Maybe for using it as a boost regulator/ governor.

Regards
Sutripta

I wasted some trying trying to find the actual application number, all I could find was the same drawing as above.

Using it as a boost regulator makes sense unless we start thinking about what would happen if that is achieved by reducing the rpm of the turbo - the flow of the exhaust will be restricted and will cause higher back pressure at the exhaust - how is that good for performance?

Originally Posted by dhanushs

Sutripta Sir,

Are there any production vehicles with electric motor to power the turbo?.

Might be the boost regulator/ governor too, but then, isnt it a by-product?.

- Dhanush

If they are patenting this, there should not be any production or non-production vehicles ever produced (otherwise this isn't new)


If all they want is supercharger at low rpm and turbo at high rpm - then that can already be done by using a combination of the two - a small super + a large turbo. I believe Laura TSI engine already has it. In this new "innovation" All that is saved over that solution is the supercharger's compressor turbine (you still have the exhaust inlet of the turbo, and the electric motor of the super. And you still have the compressor which now has to support a wider air flow range than the twin solution of TSI)

Originally Posted by pranavt

Please don't confuse it with that trash. The electric/conventional motor is used to spin a real turbo which does cause forced induction of air. The Surbo/Turbonator/XYZ is a stupid fan in the intake pipe, nothing more.

I don't know about the Surbo technology - but even a turbojet's compressor is a fan in the intake pipe. In fact so is a "real" turbo or supercharger as well. How is the Surbo stuff different?

[vina]

Update to the above^^^

Found this link BMW Patents Its Electric Turbocharger Technology. More Power, Less Lag. - BMW 3-Series Forum (F30 / F32) | F30POST (it was right their at the bottom of the page @Scorcher referred) This explains the idea better.

They do intend to eliminate wastegate (and I still do wonder what that would do to the back pressure of the exhaust)

Otherwise also, this is like having a supercharger in parallel to the turbo - I'm not sure how is this one better than that or even better than VGT.

[Sutripta]

A number of years back, in one of the IETFs, a German company was exhibiting something similar. Forgotten the name of the company.

Originally Posted by dhanushs

Sutripta Sir,

Are there any production vehicles with electric motor to power the turbo?.

Might be the boost regulator/ governor too, but then, isnt it a by-product?.

- Dhanush

An obvious idea cannot be patented. Does not have to be prior art always.

Originally Posted by vina

They do intend to eliminate wastegate (and I still do wonder what that would do to the back pressure of the exhaust)

Both reduce power. Not working at crosspurposes.

Regards
Sutripta

[pranavt]

Originally Posted by vina

I don't know about the Surbo technology - but even a turbojet's compressor is a fan in the intake pipe. In fact so is a "real" turbo or supercharger as well. How is the Surbo stuff different?

Fooling gullible people into believing that a small fan actually produces positive pressure in the intake pipe. I do understand that the concept is the same. However, a small fan spinning at a few thousand RPM is not effective enough to produce boost. The advertising specifically highlights that lie and charges anything from 20-100 USD for it.

They do intend to eliminate wastegate (and I still do wonder what that would do to the back pressure of the exhaust)

Backpressure isn't usually considered beyond a point. All exhaust manifolds on factory cars are quite restrictive anyways.

[AlphaKilo]

Good discussion! The question mark in the title is apt because this will not end the turbo lag, rather this is going to be a costly technology probably the M-series will get this technology(if at all it gets produced). On the other hand, I see a future for parallel and series turbos taking over the market than these electric or similar funky technology. The very basic restriction of these mechanical devices is their rotating components, which have limitations due to structural vibration and the restrictions due to metullurgy. With lots of turbo power, and lots of torque coming out, the traction control at the wheels will play an important aspect in utilizing all or atleast most of the torque obtained.