Thats a good start
186rwKw = 250rwhp. Exact same as my first dyno!
The right scale is Tractive Effort and when compared with diff and tyre size gives rear wheel torque.
So 6130 N (Newtons) = 462Nm (Newton Metres) rear wheel torque. Which is 340 ft/lbs (foot pounds)
Yes, both the torque and hp curves take a little dip. Can you just remind us again of your combo & cam size? And what rpm were you red-lining at......5700?
Could be a number of reasons.......
Air Fuel Ratio (Do you know what it was? The dyno guy will have it saved on his computer)
Stock heads (should see a bit more)
With good traction your XE should do a mid to low 13 quarter.