Depends on the CAI you go with, Janetty Racing did a comparison test on a bunch of the CAI's that was a true no catch 22 test. The results varied per CAI no matter what the manufacturer printed on the box. The test may be listing in the results are JRE CAI comparison, I believe the test was done & posted in 2011. I've heard great things about CAI Inc's kit and according to the test it provides something like 12+ HP, that will probably be the one I buy when I get my car. Also is your car LS3/Manual 6 or L99/Auto 6? AFM delete/L99 tune on L99 cars help the performance greatly at least 25HP+. I have no idea what the LS3 tunes can provide, but I'd imagine with the mods you would have with the tune I'd say at least 30HP.