2011 2500 with BTR stage 2 cam, LT, air intake, and Whipple on around 7-8 psi.
Truck runs great until 4550ish on the dyno/92ish mph, or 97 mph on the street. On the dyno, it yanks timing and closes the throttle. On the street, it runs up to 97 and goes into limp mode. It runs perfect through all gears until then.
That is in true MAF mode - in SD, it doesn't open the throttle completely. A small increase from stock peak torque will add about 10% throttle but it stops there. If i set the MAF transition point to stock, it is stupid lean until it hits the MAF point.
I currently have peak torque and driver demand cranked but no benefit. I've had this truck to 127 on the dyno before the blower.
have you tried Tow Haul?
We had a weird issue with a 2012 2500 with a 6.0. tried everything with tune and in Normal it would do the same thing but in tow haul it would run up to 130 no problem.
Never could figure it out.