K & N Air Filter Opinions

[HarryMann]

I'm sure they're fine James and spacewise can be a real boon...

but not so sure your Scooby has an AFM type flow meter rather than the hot-wire, so called MAF type. Maybe those Subaru turbo hot-wire (or film) anemometers were extra sensitive, but there were problems, supposedly due to replacement (performance) filters.

[Aidan]

on something like James' scooby install in a vehicle run by a mechanic who does actually service the KandN and where it saved on fitting a paper filter housing to the vehicle in a position that it wanted to be rather than where VW intended it makes sense but in stock application for me stick to stock and replace as per service schedule or more frequent if used in harsh conditions and if you have a cyclone fitted keep it cleaned out too as that will also guide you on state of unseen paper filter

Oh I fitted K&N to the SA 2.1 velle with the ported heads and big bore exhaust and the intake noise was noticeably higher, compared to syncro long life paper filter; sold the van after the first filter service, wonder if it's been done in the last 41/2 years ?

I worked out the cost thing with the K and N you'd have to keep it more than 5 years for it to cost the same as using paper filters at GSF Man prices assuming there is no mpg difference and you have to clean it and re oil it regularly, seen plenty fitted to vans that haven't been serviced and they were strangling the intake

[faggie]

i use k/n filters on all my cars as they work out cheaper in the long run than replacing stock paper filters , on my camper van with a open style airfilter housing and a stock style panel k/n filter it produced 11more bhp on the rolling road than with stock air filter set up , the van does have a slightly modified engine

[lloyd]

i use k/n filters on all my cars as they work out cheaper in the long run than replacing stock paper filters , on my camper van with a open style airfilter housing and a stock style panel k/n filter it produced 11more bhp on the rolling road than with stock air filter set up , the van does have a slightly modified engine

11 bph increase with just air filter on rolling road ???

[HarryMann]

i use k/n filters on all my cars as they work out cheaper in the long run than replacing stock paper filters , on my camper van with a open style airfilter housing and a stock style panel k/n filter it produced 11more bhp on the rolling road than with stock air filter set up , the van does have a slightly modified engine

Are you comparing like to like? Same day, same RR, test stock, remove stock filter (must have been new else bad comparison), replace with K&N, re-test and another 11 bhp...

Even the Mfrs wouldn't be using paper filters if that were true, they spend millions gaining 4-5 bhp from the same engine