Ignition Timing and Intake Cam Advance

SpecG said:

Hi guys,

I would like to know how ignition timing and intake cam advance affect the power and torque of VR38.
Can anybody please explain this or point me to a right direction where i can get more information?

Click to expand...

have you read the Cobb atr guide ? you can carefully test adding timing on dyno to see at which point adding no longer increases torque but increases knock & stress

"Dynamic Ignition timing computation - The Nissan GTR uses a complex computational process to
constantly calculate optimal ignition timing. An internal mathematical model of engine function together
with an array of sensor information is used to calculate ignition timing. The values in the timing tables
are referenced within this computational process but are NOT traditional ignition timing in degrees before
top dead center as most tuners will recognize. These numbers are best thought of in terms of fuel burn
time. The numbers in these tables do heavily impact timing calculations so timing can be adjusted.
Higher values will lead to higher ignition timing and lower values lower ignition timing. One to two
increment increase in table values will lead to a single degree increase in ignition timing.
Detonation based timing adjustment - Ignition timing is also adjusted in response to detonation. The ECU
actively reduces timing in response to detonation. Timing adjustments in response to detonation are
logged with the "knock Sum" monitor. Each degree of removed timing is reflected by a -300 knock sum
increment.
Generally speaking, higher ignition timing supports higher torque and greater power. However, ignition
timing should be increased with great caution. Higher timing yields higher cylinder pressures and this is
limited by fuel quality and the mechanical limitations of the engine. Too much timing will produce knock
correction when fuel quality is limiting. When fuel quality is high, ignition timing should ONLY be added
when its addition produces a substantive increase in torque and power. If increased timing does not
increase torque the extra cylinder pressure is simply producing unnecessary stress on engine components.