[Gaz64]

I was puzzled as to why the two curves don't cross at 5252 rpm, then I realised the the scales are HP and Newton metres.

What dyno operator uses HP (imperial), and Nm (metric).

So you have 441 Nm, not 441 Ft/lbs. 441Nm = 325 Ft/lbs.

So at 5252 rpm, you have about 325 HP, before you then go onto 354 Hp at 6600 rpm.