This is probably a silly question, but was the XR6 turbo actually an F6 Typhoon perhaps?
That's bugger all drivetrain loss for a 240 flywheel kw motor
Unless they're playing silly buggers with numbers like a few certain Japanese manufacturers have been known to do
But that being said...... all motors are not created equal
I've seen a lot of dyno graphs of XR6 turbos running up 185-195rwkw dead stock, but then again I've seen a near standard series 2 R33 run up 170 at the wheels as well