audi v8 fsi

[pyry]

not exactly f1 related but i thought it was interesting
http://www.fourtitude.com/gallery/galle ... di%20Booth#
what are those curved structures in between the v configuration? i read that the engine has a kind of camshaft balance in which there are opposing weights to the pistons to balance resonances out, anyone have any more specific detail on this? quite a piece of engineering, max torque at 5500 rpm, 430nm, but does over 400 from 2250-7500 rpm, with peak power of 420hp at 8250. fsi rules

[dumrick]

That is the intake manifold. The length of the intake pipes is determined as a function of acoustic variables, therefore it is not direct like usually is seen in competition engines.

[riff_raff]

pyry,

That engine may have some F1 related hardware. It is a GDI engine. I've heard rumors that Ferrari is using GDI on it's F1 engines.

The benefit of GDI vs. port injection is that GDI allows a higher air mass flow throught the intake ports, produces a lower SFC at part throttle due to stratification of the intake charge, and increases the knock limit at WOT due to lower cylinder charge temps.

Of course it's more expensive and complicated to get an injecton system to operate at the conditions required by a GDI 18,000 rpm F1 engine versus a GDI 7,000 rpm road car engine.

Finally, variable length intake and exhaust systems are not legal in F1.

[Guest]

doesnt bmw have variable intake? besides, isnt there a difference between fsi and gdi, they are quite similar but i have understood that fsi is somewhat more advanced?

[bcsolutions]

doesnt bmw have variable intake?

Quite a few production cars have a variable intake system. However, as riff_raff pointed out, it is not legal within F1.

[Reca]

We already discussed GDI last year and the situation isn’t changed since then AFAIK, no F1 engine use direct injection.
Variable length intakes are legal and almost universally used, since mid 90s at least, they will be banned only next year with the introduction of the ridiculously constrained V8.

[ib141]

Not wanting to sound stupid, but what is FSI? do you know a site I could look at to help? thanks in advance

[bcsolutions]

If i'm not mistaken FSI is a VAG acronym for Fuel Stratified Injection. I've put a link to an Audi page below, it's fairly basic but offers some insight into the technology.

http://www.audi.co.uk/acs/ownershipbene ... p?id=11614

[riff_raff]

2005 FIA reg's:

"5.4 Exhaust system :
Variable geometry exhaust systems are forbidden."

Apparently, variable intake geometries are OK though.