That is serious torque - I have the Morgan lightweight alloys on my Plus 8 400ftlbs is about right I think which is a big bar at about 3' I think.
They are similar fixing to the Aero I believe.
Aero wheels should be tightened to around 380 lbs/ft
They don't come loose at that. Most of the issues are because people don't torque them up properly, and guess "a big bar at about 3ft....."
I broke a 4 ft 1/2" drive breaker bar trying to loosen these off
The wheel nut is the same as the "lightweight" alloys (a bit of a misnomer as they are actually heavier than the standard alloys). Although on the Aero the wheels are peg drive rather than spline drive as on the +8
Simon @ SiFab.co.uk