Ask forum member, MarcS, about my '11 5.0L. He works for The Mustang Shop in Auburn, WA where I had the dyno pulls done and he witnessed the pulls and knows what little mods I have. Other people in the shop, Marc, and I were guessing I'd see about 375 to 385 rwhp based on the limited mods (SCT canned tune, K&N drop in filter, and GT500 axlebacks). All three pulls were over 400 with a best of 409 rwhp so we were all really surprised!
So, I went to the dragstrip a couple days later to see if that dyno number made sense. Before racing, I calculated that 409 rwhp would mean a 116 mph trap speed so I was very skeptical. However, after experimenting with my launch technique for a few passes, I was rewarded with 4 passes over 116 mph and one over 117. Those trap speeds support the 409 rwhp figure. On a side note, I weighed my car on the drive home from the track and it was 3,720 lbs with me in the car (I weigh 180 lbs, so the car is 3,540 lbs).
The only other mods on the car have nothing to do with power production: adjustable LCA's and M&H Racemaster 275/50/17 drag radials.
So, perhaps my car really is a factory freak. It is fully broken in with 10,000 miles on the odometer and I have driven it very hard since day one, which I've always preached as the best way to break in a new car. Oh, and this isn't my first factory freak, so I believe that my method of breaking in new cars works. My 2000 Mustang GT, 2003 Mach 1, and 2007 Mustang GT all went quicker than most people expected. I bought them all brand new and drove them hard from day one.