Originally Posted by E36toF30
Yeah, that's part of it. The other reason is elevation. The OP said he's in Colorado; I'll assume somewhere near Denver, which is about 5280 feet. That means the naturally aspirated Camaro loses a straight ~15% of it's power compared to sea level, meaning the 426 hp Camaro effectively has more like 360. The turbo charged engine in the 335i will have slightly more turbo lag at elevation, but once the turbo is going it makes virtually the same power as at sea level. Plus, BMW does tend to underrate their engines a bit.
Didn't realize he was in Colorado. So yeah, that too. If you want to get technical the 335i actually makes closer to 320lb-ft of torque if you look at actual hp. And not to mention if you have the 8-speed auto, you have closer spaced gears in the Camaro which do a better job keeping you in the ideal powerband combined with faster shifting, which again aids in that perception.