There are several factors that can contribute to detonation.
Head clearance. percentage nitro used, plug, ambient temperature and altitude.

On cool days 50 to 75F almost all engines will perform and put out lots of HP. On those kind of days detonation with stock shimming and 30% nitro usually is not an issue.

On hot days (track temps at 100F or more) detonation may become more of a problem. Head shims will usually fix the problem, but many guys will also drop nitro content to 25% and even 20% and this will also alleviate detonation. If you run lower nitro you will need to lean out the motor more and retune at the track.

Changing to a colder plug will also help with detonation as well.