Noted Pontiac Tuner Dave Miranada who used to be involved with Superjet Specialities in Queens, New York.
He deduced that the detonation threshold of a Pontiac V8 was right at 185 psi cranking compression.
Dave also came to the following conclusions:
The optimum (maximum) cranking cylinder compression pressure for a performance/street application using 93 octane fuel = 160 -170 psi
Changing the position of the camshaft (and thus intake valve closing event) by 4° changes cranking cylinder pressure by about 5 psi. (Advancing increases pressure, retarding decreases pressure.)
