I don't usually have it on that setting, but what temperature was the oil when the power dropped as you should be on 70c anyway before opening up the engine.

 

86 degrees when I got 423 and around 102 when it wouldn't go over 377.

You don't get full power until the engine warms up.You can tell when that is as the icon for the engine oil stays blue when it's cold and goes white when it is ready to go.

 

I've been monitoring the HP level much more since this thread and I haven't yet seen it drop below 423 hp. It might be because the air temperature is a bit cooler now but I also wondered if the drop you noticed was at a higher altitude.

 

for me its always on 423...

 

The figures aren't an absolute correct figure, even after a remap or tuning box, it still says 421/423.

I think it's just a relative reading taken off a sensor or two, and a lookup table, rather than anything clever.

 

I agree but a big reduction like Paul's is strange unless it's a sensor error but the torque number was holding up.