ArcticZ28

iTrader: (14)

http://www.audiworld.com/news/02/fsi/content.shtml

I've read it a couple times now but I'd like to spark a pro's/con's discussion, as I already have a couple of questions that maybe others can answer.

In stratified charge mode...
1 - If the fuel is vaporized in the chamber, wouldn't it require a lot of time to allow for this vaporization before ignition (since usually it's already done before it enters the chamber)? If so, they say the fuel is sprayed in the compression stroke, which doesn't seem like it allows for much time before ignition to get this done.

2 - "An additional benefit: during combustion, a layer of air insulates the hot, ignited mixture from the cylinder wall. This cuts the amount of heat lost to the engine block and increases the engine's operating efficiency." ... but as this charge burns and mixes with this extra air, would that not cause it to burn hotter (less fuel and more air = hotter burn, right?)?

gametech

iTrader: (1)

#1--I don't know.
#2-- I think applies to light load conditions.
Audi is NOT the only manufacturer experimenting with this technology. I'm very curious how this turns out.

chuntington101

its a great piece of kit. have you seen the pistons?? very strange shape. what they do is try and mix the air fuel mixture up in the cyclinders. i think thats what they are goiing on about in 2) of your post.

as for the vapourising, have you seen the injector preusres they run?? very very high, almost that of diesels i think.

and as gametech says their not the only ones doing it. be nice to see if there is any advantage on the performance side of things.

Cheers Chris.

ArcticZ28

iTrader: (14)

"The injector, which is located under the input channels, is supplied by a high-pressure pump driven by the camshaft and a single distribution pipe for all cylinders, the common rail system. The injector controls the injection time to within thousandths of a second at injection pressures of up to 110 bar."



Now, if only the turbo would run in a linear rate

tomustang

I think Audi needs to refine it alot more, what they want out of it is the combination of more power and less fuel consumption, from what I've seen from audi is that most of their competition has engines that output the same or more power. Audi needs to work on trimming more fat before working on engine achievements

PAGregSS

iTrader: (10)

Sounds very similar to the fuel injection being used on the new Solstice GXP and Saturn Redline motors.

http://www.highperformancepontiac.co...injection.html

ArcticZ28

iTrader: (14)

"In this way, fuel is metered and delivered in a finely atomized spray, which, during the intake stroke, is introduced into the chamber near the intake valves, in direct line of the spark plug."

It seems as if GM is differing by spraying on the intake stroke, rather than the compression stroke like Audi.

kahunaking

iTrader: (1)

The mazdaspeed 3 uses the same style of injection. The thing makes a ton of power for a 4 banger and 280ftlbs of torque too. When we hooked up the obd 2 scanner to it the fuel pressure was at 1100psi or somthing like that.

ArcticZ28

iTrader: (14)

Sounds about right since Audi is claiming up to 110 Bar = ~1600 psi.