High speed ignition tables

K-Series Programmable ECU installation questions / support issues
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Lewvr6
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High speed ignition tables

Post by Lewvr6 »

I'm curious, after looking at my calibration a few others including kmanager base maps, I notice it seems to be normal to have high ignition values in the low load/high vacuum columns, and lower end of the table. Talking about 40-42 for most of these sites.

What is the reasoning for this seemingly aggressive ignition? I guess it's good for response when getting on the throttle? but I wonder also how this affects deceleration?

I have read elsewhere (admittedly not Honda related) that it increases engine braking? And therefore would reducing these ignition values decrease the engine braking effect? If they were lower what other effects would it have?
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Hondata
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Re: High speed ignition tables

Post by Hondata »

The ignition advance it largely determined by the mixture burn rate. Low cylinder pressures (low load) has a slower burn rate, so the ignition is more advanced. High cylinder filling (boost) has a fast burn rate, so less ignition advance is required.
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Lewvr6
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Re: High speed ignition tables

Post by Lewvr6 »

So if you lower the high vacuum (low load) cells to less advance/what would be the effect? Would there be any harm to the engine?

I have briefly tried less advance in these cells and found it much nicer to drive at lower speed/partial throttle, with no noticeable negative effect at high speed/revs.
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Hondata
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Re: High speed ignition tables

Post by Hondata »

Low speed / partial throttle but using the high speed tables?
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Lewvr6
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Re: High speed ignition tables

Post by Lewvr6 »

Yeah just the high speed tables, the low speed tables already have much less advance values.

I was hoping to reduce the engine braking effect, which was a noticeable reduction, and would be to my preference on track-my worry is whether this reduction in ignition advance in the first two columns, would cause any harm to the engine-mainly the potential for raised temps on the exhaust valves?
Lewvr6
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Re: High speed ignition tables

Post by Lewvr6 »

Also, for deceleration conditions from high speed/rpm, which ignition table is used- high or low? As the throttle is shut but rpm high?
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Hondata
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Re: High speed ignition tables

Post by Hondata »

My query was why was the high speed table being used at a low load. Perhaps posting a datalog would be best.
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