Sudden Boost?

[SmokeyMax]

I've noticed that running my 03 Dmax Ali around 80MPH+ my throttle response changes. It seems like the engine decides to give me all shes got. Sound changes (like a big block roar) and there is abrupt surge forward then I let out a little and it abruptly goes normal. It can be kinda annoying as your head keeps going forward and back as it's touchy. This oly happens 78-80+ and works great when Iam towing my 20ft Bass Boat. I have owned other turbo D. trucks and am familiar with a gradual boost pressure. This almost seems to be a fuel rush but no smoke out of the TP? I was wondering if anyone else has noticed this or if it's a change to 03. I wouldn't consider it a problem as I have 5,000 miles she purs like a kittin.
PS she's bone stock.