But your only example is Le Mans when Audi was marketing that technology for its street cars and where fuel efficiency is very big.

I don't see GDI dominating in ALMS or really any other series? I mean, once again, is a hybrid diesel the ultimate race car setup because Audi is winning Le Mans with it now? Or is it just that setup gives them great efficiency for a 24 hour race?

There's a paper that used a turbo DI gm engine and compared DI to PFI for all sorts of things from knock to flame progression with different DI injection timing with the incoming air. I think there was a section on droplet size and how heat from compression affects vaporization when they compared ethanol blend fuels. I'll see if I can dig it up. It was a big dissertation from a MIT guy with the head of sloan as corresponding author. I like reading things from sloan. But pretty much the same as what you're saying. Issues to keep in mind but not necessarily game breaking. Time will tell, though. Valve float and airflow from all components need addressed first.

N54 already operates in homogenous mode

near TDC is stratified

it's already 'started sooner'

and it can inject x many times per cycle (it's in the tech data for the injectors)... 4 or something?

Good info. At high rpm DI has disadvantages to port fuel, but nothing sheer size, pressure and precise control can't counter of course. Nice specs, thanks!

I think a bigger issue for our DI at high rpm would probably be air fuel mixing, injecting too late at high rpm also lowers the window for the mixture to, well, mix. That will probably manifest more in very high powered cars at high rpm than what we have so far, but something else to keep in mind. Personally I love DI, as the technology progresses these side notes seem to matter less and less, which is a good thing.

Ok this is a good example but if it's so dominating why was GDI ditched and no longer used by Audi in Le Mans?

I really can't think of any racing series using direct injection especially with NA motors and high revs. The Audi motor was a twin turbo unit and Le Mans tends to emphasize efficiency more than raw power because the less pit stops the more distance you cover.

How is it false when the window gets smaller as rpm rises?

Its false in the sense that its much harder or impossible for DI vs a decently sized port fuel injector. DI injectors have plenty of fuel overhead if you read the conti literature on them. About 500hp static flow per inector or enough fuel for about 3000hp in an N54- at stock fuel pressure. Yes you can't run them that hard but even at 1/3 dc, that's 1000hp. That's why I also said I'm more worried about block issues before running out of injector.

And how are you supposed to do that?
Code in the dme. Somewhere there is a table of injection start by CAD, rpm and prob several other factors. The dme at lower rpms and load uses multile injections already. Cake for proefi or equivalent when it arrives.

In what series?

hmmmm if it comes with more than they're stating... that may not be a bad price then...
unless they plan on upping the price

might sent them an email just in case

wonder what's so hard about the springs, there's countless designs in other motors, all of which have solutions