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Maximum torque @ 16-18 degrees past TDC

EFI Tuning Fundamentals

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Hello mates,

Anyone has an idea why (physically) the maximum torque happens 16-18 degrees past TDC ?

Andre has gone into this in one of his videos and/or a thread here.

In short it is a function of the burn speed of the fuel-air mixture in the cylinder, the timing, the rpm and the geometry of the piston/connecting rod/crankshaft.

When your peak pressure occurs in that range of crank angle degrees, the piston is just starting to accelerate and pick up speed towards bottom dead center in the expansion stroke. That cylinder pressure helps accelerate the piston downward and create more torque.

Many thanks for your input guys !

What vehicle?

Just curious.

Hey Kyle, this holds true for any piston engine. Just remember that we aren't setting the ignition timing to 16-18 degrees. We're setting the ignition timing to whatever it needs to be in order to generate peak cylinder pressure at 16-18 deg after TDC. I know a lot of people confuse the two.