I combined some data in Excel so I could look at the basic shape of the HP curves of these three engines. The numbers are from the more optimistic Dynojet curves I've found while searching. I used 2 2011 GT and 2 2011 GT500 curves, but just the one Boss curve from Insideline.com. I didn't feel like doing the torque curves

 

I like magenta.

 

It's amazing to see a HP curve just flatten out and stay at peak power over such a broad RPM range. Look at the Evolution Performance curve - car just sits at peak power from 6200 RPM to 7700 RPM - you just don't see HP curves like this very often.

 

Looks like a stock Boss does that

 

I agree & consider the Evolution a "raised" version of the stock curve, albeit with an offset that makes comparison to the dynojet numbers difficult. Also, not sure it it's a property of the Mustang Dyno or the averaging of the curve, but the "flat" is easier to see on the Evolution curve.

 

For the money I'll leave it stock
But I would like to see other dyno results of other Boss owners.

 

I'll be dynoing mine once it's broken in.