The Boss is much quicker around the track than the GT-500 already.
everyone seems to think that but so far the evidence just isn't supporting it. The only people that I know of that have done a head to head test is InsideLine and the Shelby beat the Boss around Streets of Willow by half a second. And thats a relatively tight track, and the Shelby in the test was a well abused press car with a notchy tranny.
If you look at VIR times, in order for the Boss to be "much quicker" it'd have to be running lap times roughly equivalent to the 430 Scuderia, and as much as I love Ford, I don't see that happening.
From what I remember of Laguna Seca times I've seen, the LS Boss is 6 or 7 s seconds quicker than the 2010 Shelby, but the 2011 Shelby is a LOT quicker than the 2010. On VIR the 2011 was actually NINE seconds quicker than the 2010.
There's no doubt that the Boss is the superior track car for other reasons (better balance, no heat soak, lighter weight = brakes and tires hold up better, etc), but as far as just turning in the absolute best lap time, they seem fairly equal and if anything the Shelby has an edge. What the Shelby gives up in balance and precision it appears to make up in grip and power. I would imagine the monstrous amount of torque the Shelby has on tap comes in handy pulling out of corners, for example.
I'd love to see some more head to head tests, other than the InsideLine one. Kind funny that right now the best competition for the Boss isn't from Chevy, Or Dodge, but is another Mustang.
It's definitely a good time to be a Ford guy.