
This example is tuned by Kevin Baldi of Labworx and @kbaldi29 was able to get some big power and torque out of it.
On 93 octane pump fuel the car is making 891 rear wheel horsepower and 719 lb-ft of torque at the rear wheels.
Look at how far it is revving out as well:

It is making power to roughly 8800 rpm. The factory redline is 8500 rpm for the M840T.
A very nice top end here making for a monster McLaren.