Originally Posted By: badtlc
Originally Posted By: jrustles
They never thought of the high-compression, standard displacement,
atmospheric route. Well even if they did, they would have had to pioneer that development completely on their own, costing more money overall and with no time to do it. Ford et al are kind of stuck at this point.
They did do that. Ford developed a 2.0L DI non turbo motor along with their 1.XL engines.
They adapted existing engineering (that they didn't even fully engineer themselves). BY 'develop' I mean Ford's own unique engines developed all by themselves as part of a unique Ford strategy like the Ecoboost V6 and their V8s.
The EB 2.0L is nothing but a beefed up base model Mazda3/Focus engine, with the exact same changes made to it as were made to the 2.3L DISI vs the regular 2.3L-- EB 2.0L is really nothing but a de-stroked 2.3L DISI with Ford-chosen EMS, turbo and other small tweaks like another hydraulic phaser on the exhaust side (a provision that the MZR engine series had already designed into it).
Same goes for the 1.6L EB and 1.0L 3 cylinder-- those engines already existed, the 1.0L sitting in-house waiting for an app, and were adapted to EB duty. A smart strategy for Ford from an economical perspective, just like Hyundai/Kia and their Theta II G4KA/G4KD engines based on Mitsubishi engineering. Hyundai Kia couldn't even be original enough to stray from the Mitsubishi coding convention. Come on, G4KD vs 4G63? lol
Same goes the Germans! If no one else had done a GDI turbo and impressed them, they probably would have a different strategy today. MB in particular now seems to need to prove that they can make the most power-dense 4cyl production engine-- totally ignoring the fact that no one buys a Mercedes (or a BMW) to get a FOUR CYLINDER ENGINE.
As for chamber cooling, DI works by exploiting the 'latent heat of evaporation'. By pressurizing the fuel to hundreds of bar, when it is sprayed, it expands and cools the greater space that it now takes up, somewhat like a refrigerant expansion valve. The cooling is directly proportional to the pressure it is sprayed at, therefore it's cooling effect has a hard limit.
Some traditional cats can't manage richer than stoich mixtures, but I strongly suspect DI unit use different cat technology like single nano-deposited precious metals. Widebands confirm that turbo DI runs rich, the soot seen around tailpipes is an artifact of not only rich, but incomplete combustion- and new car cats are really efficient and mask smoke output. If the cats see outrageously rich condition under load alone, then I suspect the cats can manage the additional oxidation load during high flow conditions, where the mixture's time in contact with the substrate is limited, unlike a car that runs rich all the time and can melt it's cat even with light driving.
Three major factors that will make the best of turbo-DI tech
-better fuel quality
-even more advanced management techniques
-bumping up engine displacement
oh and one more thing
-steep learning curve of turbo DI engine operation, something which IMO logic controls should compensate for to maintain consistent performance
