Optimized timing is that which results in the most fuel combustion energy being delivered to the crank in the form of rotational torque, and ultimately to the wheels. It is where our 35% engine efficiency comes from at WOT. (2/3rds of fuel running through the motor is wasted heat.)
I have been doing some research and it seems we often overadvance our tuning.
Timing and boost. Adding boost, speeds up the flame front, so timing must be retarted to prevent that coveted efficiency from going south.
Timing and IAT. Same thing
just starting a discussion thread. The moment you jump off the 5 second dyno, everything changes. Intake charge might be 100 degrees for a race launch, but after 5 minutes towing up a grade, 200 degrees. Yet no timing change. Add the increasing cyl head temp. Fuel with increased Cetane. Dry environments, even a free flowing exhaust. All these factors add to the requirement to retard for optimization.
I just seem to have it stuck in my head, advance is possibly overused, particularly when dyno tuning.
Timing and ....
Vehicle Systems Engineer/Professional Tuner
04.5 GMC 2500HD SRW LLY
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