Cat timing advance

The ECM decides what part of the lobe to use as the Cam Injection lobe is driving a PUMP not an injector. Grinding the Cam lobe will have no real affect on timing at all.

 

Yes directly related to Boost in this instance.
Wrong quote sorry see below.

 

Yes,
Directly related to Boost in this instance.

 

some strange jumps in a couple of areas, other than that looks normal. What emission engine it is from? I've heard a rule of thumb that you should have about 1 degree/100rpm, if those are degrees then it is about 10 degrees retarded from optimal at 100% load
.

 

Somewhat related question:

On older engines, did "nox tunes" mostly ###### timing? If so, how much?

 

you need to change the injector calibration map and smoke limiter map to get smokeless and well behaving engine, that is hat good tuners always dose.All electronic engines are low nox, at least 5 degrees retarded.

 

I'm talking about the late 90's early 2000's tunes that engine shops were required to put in trucks on the road after the EPA lawsuit. These tunes are known as "low nox tunes" and kill power and mpg.

 

the injection timing is changed by controling the spill valve in the unit-injectors,when its closed the injection starts.The only way to change the timing as you wish is to reprogram the ecm