Ever since I got back from murillo having it dyno tuned I have noticed a distinct smell whenever I go WOT. I figured it might have been belt slippage but it never drops below 13psi with a 6lb lower. Today on the way to work it was 60 degrees (im in daily driver mode) and I had to pass this slow mover in front of me Once i get pass him I smell the usual smell and decide to go ahead and turn OD on just to see if it would actually pull above 115. Everytime I have raced anyone I have always run 3rd out which stops at 115@5000, So today I decided to try it and as soon as it hit top of 3rd goin into 4th it falls smooth on its face like someone was holding the brake while driving.

Whats the easiest way to fix belt slippage ( if thats what he problem is?)
Why did my truck fall on its face when I hit 4rth?

Any help would be greatly appreciated


mods:
K&N cone filter
6lb lower
SS bassani
FTVB
boost bypass
dyno tune by Murillo (has 3 tunes, daily, winter, race)
400rwhp anf 505rwtq in daily driver tune