At the the 2009 SEMA show I discussed this with K&N, told them my concerns, what others on this forum thought and that something is really amiss.
I haven't read their website, but they do claim to use a "horsepower under the graph" way of calculating horsepower, not just on peak figure. Their system is supposed to be explained on their website. I'll try to study what they explain on their website and see if a feeble mind like mine can get a grasp on thier concept.
I also complained that they did the run in 3rd gear....what the heck??.... Again, they expained that 3rd gear was used to give a smoother curve
Lastly, I was told this was K&N's owners car...an early 2008 that had some computer issues. The thought that maybe the car wasn't running perfect was also considered.
I'll get ahold of the guy I talked to at SEMA to see about re-running the test with a couple of other GEN IV's. To K&N's credit, they listened to my concerns, were interested in clarifying this problem and trying to figure out what is going on.
I'll see what I can do to get a re-test....if there are any stock GEN IV's in the SoCal area that would like to be used as test mules, P.M. me. I don't have any idea if K&N will do anthing to compensate you (free intake system or just free dyno time) but I'll find out. I am also thinking that the stock system is very good...but I've got to admit the K&N system does "look" pretty cool. If it can be proven to pump out more power (especially trap speed increases at the drag strip, more important than a dyno run IMHO) I would definately consider buying the setup.
Cheers,
George