Electric supercharger fitted by Audi as standard

[obi_waynne]

Heres an eye opener! The electric supercharger fans will love this.

Audi are working on an electric supercharger for their TDI 3.0 engine! http://www.autocar.co.uk/car-news/motoring/audi-reveals-electric-turbocharger-technology

Impressive spec, it uses power from the regenerative system.

Will we see more of this sort of thing from other makers?

 

[T9 man]

Well I'll be one of the first to applaud Audi if they pull this off and make it into full production. Does this mean we may have to stop taking the mickey out of those Ebay wonder specials? :blink:

 

[old-git]

I doubt it. Audi's fan will turn a LOT faster than the DIY versions on offer. It is just another way of achieving forced induction but with a fan speed fast enough to make it work.

 

[davalav]

Great... Now we will have the corsa chavs telling us " I told you so"! haha

So they are replacing a conventional supercharger with effectively a more efficient and faster spooling electric supercharger?

 

[old-git]

The fact that a fan will increase boost pressure was never in question, it was the speed of the fan that was. Electric ebay fan 1-2000rpm. Turbo fan 100000+rpm. A slight difference

 

[hicusdicus]

The only electric super charger I ever had dealings with came with batteries, not included.

 

[HDi fun]

20,000rpm should be OK with a positive displacement pump. Mechanical superchargers don't run the 100,000-200,000rpm that turbo superchargers run at.

 

[SLEEPER]

The difference is that the " chav " electric superchrger is a fan in front of the normal induction trying to push air at normal pressure into the induction. The increase in volume of air is so small as to make the system only good on the internet.

If I have understood it correctly on the audi system the exhaust gases which are not useful for the conventional turbo at low revs are driven by a fan at low engine speeds.
Because this gas is already at a much higher pressure than the normal air would be in the "chav" system the practice works (apparently)
This could logically work as that air isnt being used for anything

Incedently the article isnt 100% accurate because it says that twin turbos work by having one small and one large turbo. The smaller one spooling up quickly with the second larger one giving power at high rpm.

If you are using twin turbos it is often better to have two turbos of the same size working at the same time if low down power is the aim as the "turbo kick" comes as soon as they spool up to operating speed.
This will always be earlier as they have smaller wheels so the power will be available earlier with the top end power being the sum total of both.
You do need certain engine charachteristics to be able to do this and the turbos have to have a certain type of compressor map but both of these can be designed at the outset.
There also isnt a flat spot between the the first maxing out and the second coming on full which is the bane of a lot of twin turbo in "series" set ups.

 

[obi_waynne]

I hadn't picked up on that subtle difference Sleeper, so this one accelerates the exhaust gasses, spooling up the turbo more quickly and probably helps scavenging after the combustion phase. - am I right?

 

[SLEEPER]

Not quite
QUOTE
Audi’s electric turbocharger sits in the induction system, downstream of the conventional turbo and the intercooler and is normally not operative. However, at very low speeds - particularly from standstill - the air charged by the main turbo is re-directed through the electric turbocharger, which is already spinning at high speed, and pushed with much greater force into the engine.

or

At low rpm the exhaust gases normally are wasted because although the lower volume of air may be able to turn the turbo vanes it cannot turn them quickly enough to produce any practicle boost.

The important bit is that any exhaust gases ,even on tickover , are at a much higher pressure than normal air ( if they were the same they wouldnt come out the exhaust.)

lets call this air "lower pressured" air - ie most defiantely higher than atmosphere pressure but lower than operating pressure required to produce any boost.

So this "useless lower pressured" air is diverted to the induction system with a fan behind it and thus "useless lower pressure" air becomes useful higher pressured air

Simplzz :cheesy:

 

[claymore]

It sounds more like my setup to me, basically the electric supercharger is compound charging the air coming from the turbo.

 

[SLEEPER]

quite possibly