Your power curve isn't bad but I looked through what info I could find on the interwebs and put together an optimistic but reasonable set of data if you want. This is the meat of it:

torque: 3709
volume: 18.1

torque_curve[]: (250, 0)
torque_curve[]: (300, 0.1)
torque_curve[]: (500, 0.39) #1066 lbft, about right for an 18L engine off boost
torque_curve[]: (800, 0.47)
torque_curve[]: (1000, 0.71) # 521hp
torque_curve[]: (1100, 0.85)
torque_curve[]: (1200, 0.95)
torque_curve[]: (1300, 1) # 677hp
torque_curve[]: (1500, 1) #781hp
torque_curve[]: (1600, 0.96) #800hp
torque_curve[]: (2100, 0.73) #800hp
torque_curve[]: (2200, 0.35) #400hp
torque_curve[]: (2250, 0.0)

rpm_idle: 600
rpm_limit: 2300
rpm_limit_neutral: 2200
# Allows for wide gears with up to a 0.5 drop per gear(Allison 4700 0.54). Closer ratios also work well.
rpm_range_low_gear: (900, 1800)
# Expects tighter ratios in the high gears. Closer than 0.6875 (12 speed about 0.71, 18 speed 0.85)
rpm_range_high_gear: (1100, 1600)
rpm_range_power: (1300, 2100) # might need to adjust this to (1050, 2050) to make sure the transmission gets the shift done before falling off the cliff above 2100 while keeping it wide for 6 speed transmissions, or (1500, 2050) to keep it in the powerband for 12-18 speed transmissions.

engine_brake: 2.0
engine_brake_downshift: 1
rpm_range_engine_brake: (1200, 2100)
engine_brake_positions: 3
adblue_consumption: 0.0