Quote:
Originally Posted by Carolina Dyno
On top of that they have to meet strict emissions standards. That's where the money is spent.
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Serious understatement. Huge amounts of research was/is done to minimize the amount of time and air flow before the TWC reaches light-off temperature and the O2 sensor(s) provides useful feedback. The bulk of preventable emissions happen during that early part of the driving cycle.
OEMs are really creative at dealing with this... with injection methods, stratified combustion chambers, valve timing, knock-based control, and some really impressive prediction algorithms that emulate the O2 sensor behavior as things warm up. All to meet the Tier 2 (etc) targets.
There's still plenty of value in these complex systems, but Carolina Dyno seems to be focused on supporting reliable race cars with high power density. To make high-power DI reliable, you're diving into the deep end of combustion chamber modelling (which is a dark art even with the right software). Couple that with the early issues we had with the DI system, and I'd be hitting the eject button too.
Keep up the good work OP, and know that the silent masses enjoy your posts.
And for the sake of the forum:
60 secs/min * 2 rotations/cycle / 10,000 rotations/min = 12 ms
You generally don't want to run injectors over 80% duty cycle, so the open time will be between 0 and 10 ms. You also have to consider the 0.5 - 1.5 ms latency of injector opening for most systems.