I own a IR 2135QTiMAX, which is the the quiet version of the 2135TiMax. It is rated at 780 working torque, 1100 ft/lbs nut busting torque.
While I like the gun, I don't think it lives up to its rating. I just bought the Nitocat 1200K to remove a harmonic balancer bolt that my IR 2135QTiMAX...