BMW Patents Its Electric Turbocharger Technology. More Power, Less Lag.

[Bowser330]

Check out phantom electric superchargers. They are using electric motors to drive centrifugal compressors.

They have dyno proven results in several types of cars.

Unfortunately the systems are rather small however I wonder if two systems one for each turbo could work on the S55.

Compounding turbo technology could be an alternate to turbo upgrades, by pre-pressurizing the air charge the pressure ratios are multiplied and the stock turbos can produce higher than normal boost pressures more efficiently.

Thoughts?

[crashtestdummy81]

I thought this all initially sounded good but looking deeper the advantages seem to be unavailable from such a system under real world conditions.

Using electricity to drive the T/C at low engine speeds will help reduce lag but the electricity has to come from somewhere, unless you are driving with sufficient load after pulling away (a situation where a normal waste gate would be opening) there can be no electric generation without slowing the turbo, the charge used for spooling the turbo will need to be replenished from the vehicles electrical system.
Conversely If you are driving under high loads where you have plenty of excess exhaust to drive the generator this charge needs to be stored somewhere, should the battery reach a state of full charge you have no facility to stop the turbo over spooling unless the waste gate is retained.
Based on this it would seem that the battery sizing and initial charge state would need to be tailored to the actual driving conditions the vehicle is about to experience to be fully effective.
Other manufacturers have had success with combined turbo+supercharging which removes the need for the (heavy) batteries these systems would require. The supercharger is clutched in only at low rpm before the turbo spools up or under heavy throttle for increased performance, so as to minimize power taken from the engine.


Ultimately though, I feel that the anti lag system employed in the S55 (even though I'm not really sure quite how this works) is sufficient to render the concept of electric turbos redundant.


The electric supercharging concept mentioned in the previous post may be suitable as a performance upgrade but you would have to consider the size/weight of any batteries required to run this for any sustained length of time. A mechanical supercharger would be a more efficient option should you consider using the vehicles existing (or upgraded) electrical system as you cut out the losses associated with turning mechanical energy to electrical energy, electrical resistance and then turning it back to mechanical energy again.
An alternative idea would be to use the electrical supercharger like a rechargeable NOS system, having a much smaller battery being trickle charged from the vehicle when not in use but giving a short term bump in power at the push of a button, only when "needed", before waiting for the battery to recharge.

[Boss330]

Originally Posted by Bowser330

Check out phantom electric superchargers. They are using electric motors to drive centrifugal compressors.

They have dyno proven results in several types of cars.

Unfortunately the systems are rather small however I wonder if two systems one for each turbo could work on the S55.

Compounding turbo technology could be an alternate to turbo upgrades, by pre-pressurizing the air charge the pressure ratios are multiplied and the stock turbos can produce higher than normal boost pressures more efficiently.

Thoughts?

Similar to this?

http://www.aeristech.co.uk/electric-supercharger

[crashtestdummy81]

The 48V 10KW eSupercharger mentioned in that link, if connected to 4 of the lithium batteries in use in the M3/4 to give the correct voltage could pull a continuous current of up to 208A, which would give you a run time of a little under 20 mins from full charge to bone flat assuming 100% efficiency.
wouldn't like to say how long that would take to charge again.
Based on the data sheet 2 of these would actually slow things down on the N55 down above about 6000rpm. 2 would also cut the run time in half.

[Bowser330]

Originally Posted by Boss330

Similar to this?

http://www.aeristech.co.uk/electric-supercharger

Yes just like that one and that one looks to be much more powerful however not clear on the availability and price point, it's looks expensive.

The phantom system was tested by this guy....http://www.wildweasel.ca/HowTo/Auto/eturboTest.aspx
He's been blogging about the crappy ebay electric superchargers and gave the phantom a test and was impressed that it works. He tests the electric supercharger with and without his roots blower to show that compounding the boost works.

I am concerned about the cfm output being enough from the electric superchargers, anyone know the peak cfm of the s55 turbos ?

[Aridk]

Boss 330

Check out this page in connection to,our earlier posts
Picture is from:
http://www.evo.co.uk/bmw/3-series/14...plug-in-hybrid

[Boss330]

Originally Posted by Aridk

Boss 330

Check out this page in connection to,our earlier posts
Picture is from:
http://www.evo.co.uk/bmw/3-series/14...plug-in-hybrid

Thanks for the link

[saxonb]

This is cool:

FullElectric Electric Turbocharger Technology (FETT)

http://www.aeristech.co.uk/full-elec...ger-technology



Aeristech’s FullElectric electric turbocharger introduces an electrical coupling between the turbine and compressor, replacing a conventional shaft layout. When using an electrical coupling, the turbine and compressor are free to operate at different speeds, meaning their design is capable of far greater aerodynamic operation.

If available, a small energy storage device (such as a capacitor, supercapacitor, or battery pack) allows the compressor to respond rapidly to transient demand. The energy storage device can be conveniently recharged from the approx. 40% excess energy available in exhaust gas whenever a turbocharger is in use.