Probably a stupid question but having just replaced my standard filter for a K&N cone filter I now have a noise, when taking foot off under heavy acceleration, which sounds like I have a dump valve fitted. I know it is each to their own but this is not what I was hoping for. I am happy for a louder noise from the air intake generally but I guess unless I put the standard box back on that is the way it is- the sucking noise is ok it is the aftermath which I was not expecting. Is a foam filter a little quieter perhaps or anything else I can do? Happy to have a better breathing car but not sure on this extra noise - I struggle enough for my misses to buy into the scoobie (wants a fiat 500 - really!!) but this additional noise is making her sink into the passenger seat even lower than normal and its giving her a bad back !! Any thoughts appreciated - cheers all - TB

 

the noise your hearing chap is your recirculating valve dumping air back into the inlet so you hear it now you have cone not the standard box that masks the noise.

 

The sound you are hearing will be the standard recirculating dumpvalve, now audible due to the shorter, resonator-less induction tract.

TBH unless you are going to have the car mapped the best thing you can do with the cone filter is probably to get rid. Uprated panel filter is all you really need on a standard-ish car, and the induction kit causes a few problems you're better off without.