K&N parts matching Champ Labs. AF3940 air filter

The Champ Labs. AF3940 air filter cross references with the K&N air filter parts below. K&N offers compatible air filters for many Champ Labs. air filters giving you an alternative.
ProductPart NumberProduct Image 
K&N Replacement Air Filter
  • Designed to Increase Power
  • Million Mile Limited Warranty
A. DL., Washington DC
Very good air filter. Had similar product in two BMW M3s in the past. Highly recommend them. Not sure if it increases HP but they are easy to clean and last a long time.
George Cambria, Brooklyn, New York
Awesome filter in my S5 with Stage 1+ 2, with supercharger pulley upgrade, made a big difference in air flow to the supercharger in low and high speed acceleration.
Celerino Lopez, New Milford, New Jersey
The installation was fairly easy, and the instructions were helpful. I still have to observe if fuel efficiency improved as time goes by. I noticed improved pick up during acceleration which was very pleasing. My only complain is that the threads on the filter bolts stripped very easy. I believe I may have stripped the threads on one of them when I tightened it, and I wasn't even applying too much pressure. I just hope it doesn't loosen to the point of disconnection.
E-1987 K&N E-1987 Replacement Air Filter
List Price: $111.99
Your Price: $71.99