Timing -v- Temperature Programming Issues
Re: Timing -v- Temperature Programming Issues Timing on a stock car is retarded as a function of inlet air temperature, manifold pressure, and determined "knock". (if this is what you are asking)
Base timing, during normal driving conditions, is determined by a simple load calculation on the engine.
g/cyl = 15 * Inlet Mass Flow / RPM
This value along with RPM is referenced against one of two timing tables, high octane or low octane igntion advance. This referenced value is then adjusted according to the ambient conditions as mentioned above.
Base timing operates independantly of coolant temperature. Knock retard adjustments to the base timing, however, are very dependant on coolant temperature. Higher coolant temperatures will yield a more aggressive reduction in timing.
So, if you are building a race car or simply a track tune, the perameters that you should be interested in to maintain your program timing are IAT/MAP and KR
If you are playing with timing on a normal car, I have found it best to dial in the base timing as best as possible, but leave the IAT/MAP and KR adjustments alone.
Good Luck,
Kevin
Base timing, during normal driving conditions, is determined by a simple load calculation on the engine.
g/cyl = 15 * Inlet Mass Flow / RPM
This value along with RPM is referenced against one of two timing tables, high octane or low octane igntion advance. This referenced value is then adjusted according to the ambient conditions as mentioned above.
Base timing operates independantly of coolant temperature. Knock retard adjustments to the base timing, however, are very dependant on coolant temperature. Higher coolant temperatures will yield a more aggressive reduction in timing.
So, if you are building a race car or simply a track tune, the perameters that you should be interested in to maintain your program timing are IAT/MAP and KR
If you are playing with timing on a normal car, I have found it best to dial in the base timing as best as possible, but leave the IAT/MAP and KR adjustments alone.
Good Luck,
Kevin
