Quote:
Originally Posted by rmay635703
I bet a little more compression, a longer stroke and lean burn would reduce carbon.
Also which Asian market GDIs go lean? Just curious.
Who said water mist has to be on all the time and always the same volume?
Could easily have it shut off near WOT. and be on during lean burn partial throttle.
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It is more about time of injection. If there is not enough evaporation, large enough droplets will be available at combustion and these provide the basis for the carbon soot. Compression and stroke have little to do with this. Look at modern diesels. They always run lean and they produce soot. And they have strokes and compressions far above what a GDI is talking about. But, the soot formation in a GDI is more similar to the diesel than to a PFI spark ignition engine.
A source in Korea has told me that some Hyundai models as well as others have the capability of lean burn depending on the target market. Many countries care little about NOx.
And yes, you are correct, you can limit your water injection to only part throttle. Of course there are in cylinder injection schemes that are worth the effort. You will not be able to leverage that with port water injection.