In Pursuit of Max Torque Timing #Motorama

Northstar V8 SC 2006 4.4L V-8 (LC3) for Cadillac STS-V

Each engine has a perfect timing advance across RPM that results in the maximum torque for that engine.  GM tucks this info into a table that HPTuners refers to as Max Torque Timing vs RPM vs Cylinder Air — the theoretical timing that provides maximum torque for the engine.

Max Torque Timeing vs RPM vs Cylinder Air

Max Torque Timing vs RPM vs Cylinder Air

The advance at various RPM points in this table may not be achievable — there could be knock or detonation at those points at this advance.  The PCM uses the table as a reference to determine delivered torque.  This is one of the few tables that HPTuners recommends the user not change.

Comparison of Actual Timing to Max Torque Timing

Comparison of Actual Timing to Max Torque Timing

This graph shows the actual timing during a 2nd gear run in green vs the theoretical max timing in the green dashed line.  You can see that the actual timing follows along with the general shape of the maximum torque timing, although generally 0.5-2 degrees behind.

Theoretically, if I add timing to move the actual timing toward the theoretical maximum torque timing — without detonating — the STS-V will make the most power.

Now my STS-V also has an aftermarket intake, and an aftermarket exhaust.  Those change the ‘equation’ a bit.  But this is what I will be inching toward as an experiment — maximum torque timing.

Feedback

What do you think?  Have you used this table as a guide for tuning?  Or are you with the “more advance is always better” school?

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