MP4-12C Engine fluttering at high RPM’s

Wondering if anyone may know what might be the cause on 12c engine, on hard acceleration at higher RPM’s 5-6k starts to flutter real bad? Engine runs good up to that point then falls right off.

 

I did figure out that when it’s cool outside it’s perfectly fine, but whe it’s hot like 90-105 it’s bad. It’s heat related for sure.