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Real ignition timing

Posted: Tue Apr 03, 2007 11:49 pm
by Razathorn
Do the K series engines and ecus use some sort of ignition timing advance based on rpm that goes linearly up as engine speed increases, making the ignition values in the map not the actual ignition timing the motor is seeing, but more like 'advance over engine base ignition'?

ignition advance

Posted: Fri Apr 06, 2007 11:55 pm
by crackerjack
I would think that you are refering to extrapolating?

doesn't the computer draws a straight line from one point to another(from one map to another) and extrapolate a number from it. If rpm is used then the straight line would be moving as revs goes up.

Re: ignition advance

Posted: Sat Apr 07, 2007 12:51 am
by Razathorn
crackerjack wrote:I would think that you are refering to extrapolating?

doesn't the computer draws a straight line from one point to another(from one map to another) and extrapolate a number from it. If rpm is used then the straight line would be moving as revs goes up.
You mean interpolation? No. I mean there is some hidden table in the honda ecu that says to use additional timing at 8k vs 2k that we are not aware of.

If you look at other engine management software for older honda engines, their ignition advances as engine speed increases, but systems based on honda ecus, the ignition stays pretty much flat. I'm suggesting there is a static advance based on rpm we dont' see.

I'm trying to get doug's opinion if this is indeed the case.

It really doesn't affect anything other that I wanna know ;)