ignition timing change proceedure
I'm having a power run on the dyno next Wednesday. Now I wanted the guys to alter my ignition timing whilst there (fuel consumption is up and engine pings when under load)
Now I thought that it was possible to get a computer estimation of the optimal ignition timing angle but the chap said that they actually hook up some headphones to the block and listen for pinging, when it stops they back it off another 2 deg and that's it. Kind of like a stethoscope I guess.
My questions are
1. Is this the normal approach or is this old-school?
2. I'm concerned that when the engine is under load (eg climbing a hill at full throttle with a/c on) the engine will still ping if there's only a 2 degree tolerance when set on the dyno. Is this a justifiable concern?