spark retard

Good day

I have Silverado 2017 with L83 and 2.9L Whipple supercharger

I've done a log file and I found out that on low RPM and High load my engine is suffering form spark retard I tried to retard the spark advance but still the same issues is there

I have this issue while driving on steady state at 120km/h and uphill or trying to accelerate on 6 gear when the car start to have positive boost

thanks

After you retard the timing was it still knock retarding the same amount?

Have you tried adjusting the burst knock parameters? This can cause knock retard issues when applying the throttle or at low rpm/high load where the engine is very knock prone.