Tuning the ignition

mrQQ · Post by **mrQQ** » April 5th, 2012, 2:54 am

Hey guys,

I've got a question about ignition timing. For each given RPM range, there has to be maximum ignition advance that gives most benefits, after which they diminish and it worsens.

Is there a theoretical calculation of maximum ignition to aim for in each RPM range?

mituc · Post by **mituc** » April 5th, 2012, 4:54 am

No, there isn't, because this maximum ignition timing advance depends on so many parameters that it's impossible to determine those values.
Gas quality, boost air temperature, spark plugs gap, spark plug manufacturer and electrode materials, spark plug heat range, gas additives, gas octane rating, cylinder pressure, spark plug electrode contamination, engine oil and its induced friction, piston temperature, grounding.

Also, with the same timing in apparently similar conditions everything may be fine and sometimes you may see some ignition retard values.

mrQQ · Post by **mrQQ** » April 5th, 2012, 5:30 am

i wasn more like talking about "theoretical optimal" value which, which would never be achieved in real life due to all the things that you've listed..

Kevin · Post by **Kevin** » April 5th, 2012, 10:27 am

Im not 100% sure here, but timing is normally advanced after peak torque is achieved. This is done by determining tdc(think thats the term). If u advance the timing 2much, it will influence the firing sequence and could cause serious damage while the piston is on its way up...this could send the rod through the block