Fred wrote:If they burn slowly, then they'll not require any ATDC timing, in any region, right?
I couldn't say for sure, but that is probably a semi-safe assumption.
Fred wrote:
Ben Fenner wrote:The amount of fuel and air packed into a cylinder to make that kind of power produces a flame front speed requiring 5-15 degrees ATDC timing to make use of the energy in a productive way.
Says who? The same guy claiming to need ATDC timing on 16psi with "high flow"? :-p
Yes. I guess so.
Fred wrote:Seriously, the flame front speed is going to depend on compression,
Yes.
Fred wrote:chamber shape,
Not really, no.
Fred wrote:fuel type,
All gasoline can be lumped into the same boat basically for speed of combustion, even leaded.
Fred wrote:and many other things.
No, not really. Assuming a burnable air/fuel mixture, combustion speed is basically related to how dense the mixture is and nothing else. (Fuel type held constant.)
Fred wrote:If done well, I strongly doubt that such figures are required or desired.
All I can say is that you should speak to 2010 Redline Pro Time Attack Super Mod FWD Champion Dez Ballard. He campaigns a 650 HP BMW Mini. I believe it is 1.6 liters displacement. It could be slightly more. Find out if he's running ATDC timing anywhere. If he's not, then I'll drop it.
Fred wrote:Seriously, you should try some *good* fuel some time, it makes a world of difference...
I've said this before, but I guess I'll have to repeat it. The timing I'm referring to is to make best torque, not avoid detonation. Mean best torque will require very late timing in instances of very high density cylinder charges.
Fred wrote:BenFenner wrote:Fred wrote:BenFenner wrote:Are we concerned with injecting for diesel engines?
No.
Got it. The fuel injection timing resolution would have to be quite more precise if you were going to support them.
It looks like you don't got it...
Resolution is easy to attain if it makes sense, there are other operational concerns for diesels which do not fit with the architecture required for spark ignition engines. Resolution is NOT the reason that diesels are not in the game plan.
I wasn't meaning to say that the diesels are out because of resolution. I was explaining the reason for my question. If diesel's are not in the main picture, then we can forget about them. I brought it up because we're talking about ignition and fuel timing/resolution in this thread. Diesels would obviously need quite a bit of fuel timing resolution. If we're not concerned with them, then we can avoid bringing them up again.
I wanted to ask this to clarify. Say for example we get a resolution of 0.50 crank degrees for timing. Would the interpolation math still give better resolution? Even if we're limited to 0.05 degree increments on the tuning "maps", could we expect greater resolution when interpolating between cell values?