KB cobra did seem weak. it should be at least door to door with and exhaust Z. at least from what ive seen my friends 04 2.8KB & supp mods tuned at 589whp walked about a car on a full exhaust C6 Z till 140 then the z started to pull back up.
Yeah seems weak...I had a newer (not sure how new) Z06 w/ full exhaust (loud!) do some 2nd/3rd gear pulls with me and I was next to him and most of the time pulling...I only have 570 to my tires....
I actually know all these guys in the vid. Kb cobra never seems to run right! There was a pro charged c6 making 600 and the exhaust only c6z. They are both red lol. The c6z is H/C/I now on e85! Makes about 630 whp. That thing is rediculous!