Its the low rpm that I get detonation knock. I slow to turn a corner and get off the gas, then back on it it will ping. Once I up the rpm's its fine. From a slow cruise to on it, it pings if I don't immediately down shift.
If you down shift in these conditions, you'll be at the higher rpm that you state it does not ping. I have a 4 speed car with a bunch of compression and I can almost eliminate the ping by driving technique and gear selection.
What is your cranking cylinder pressure?
Try a NGK R5670-7
