Elaflex

Hi all, I am new to this forum so please excuse if this question has already been asked although i did check. Is the 4.2 RS5 engine direct injection or manifold injection on the 2013/2014 model?

twentysevenlitres

All 4.2's since about 2004 have been direct injected.
The RS5 engine definitely is.

Audi nomenclature for direct injection is "FSI" - stands for "Fuel Stratified Injection" (something else in German, but close enough!).

Elaflex

Thanks so much for the info. I was told the 4.2 was the only on left injecting before the valve which therefore made it ok to covert to LPG but your info confirms my suspissions. Cheers again.

Dan

twentysevenlitres

If you were to use a liquid injection system, I don't see why it wouldn't work...
surely they can time well enough with the black box, and I would have thought the compression ratios were still within limits for non-direct injection?

I'm sure I've read of some D3's being converted (I know of a W12 for sure, but sure I've read about a 4.2 too...)

Then again, something just doesn't sit right with me when cars of the RS5's calibre are converted to gas! (thats what Aussies call LPG - petrol is petrol)

Elaflex

LPG is very cheap and you have the performance to a degree! If you want 100% you also have petrol. Gas is definitely a compromise but it makes the difference whether the car is a toy or a useable car! I am reliably informed that they can gas up direct injection but the injectors burn out on the tip, as the injector gets too hot on the gas, therefore not being able to start on petrol which they have to do to get around the ECU self diagnostic program on start up otherwise they go into limp home mode.

twentysevenlitres

I would check with another LPG converter for a second opinion.
Gas burns cooler than petrol, not hotter. You're supposed to drop your spark plugs down two heat ranges to optimise performance.
Besides which, if the injector nozzles can't stand the heat, why are they in there!!

On port injected American style V8's down here (Gen 3's and 4's), liquid injected LPG (latest tech) produces more power than petrol due to the gas having higher octane than petrol (around 110 RON).
I doubt that would be the case with something as highly tuned as an RS5 though.

Elaflex

I have actually looked into this today as it happens and there are companies that say they can do it so the saga continues. Thank so much for the advice and info chaps I will let you know how it goes. Dan