RE: K&N Air Filter
I replaced my OEM paper filter with a K&N drop in on my Challenger R/T..... Definitely a seat of the pants improvement (better throttle response) and it has increased induction/ exhaust sound just a bit.
I had removed my stock air filter box / intake tube on my 06 Daytona, and replaced it with an AFE stage 2 CAI..... IMO I would say they (K&N D..I vs CAI) seem to perform very similar, but I do not get the CAI whistle when I punch it on The Challenger!
I experimented with the CAI at the track....I tried to plug the hole on the bottom of the CAI shroud = tried to keep out as much hot air as possible.... resulted in a loss of et and mph!!!!
Our Challenger R/T stock air boxes have the same hole on the bottom as the LX Daytonas and Road and Track Charger R/Ts do. The regular LX Charger R/Ts do not have that hole.... some speculate that is part of the reason the Daytonas as well as R and T R/Ts are rated with 10 more ponies. The hole in the bottom acts as the aftermarket Volant type CAIs.
....... This is why I tried the K&N drop in this time, and I am real happy with the results! I spent $50 and get very similar performance as a $350 CAI!!! And I'm thinking about a modification with ducting the hole to a true cold air source