anyone using the K&N aircharger intake system claims 12+ horsepower gain any good or bad comments?

 

Don't believe everything you read.

 

which air cleaner do you recomend for the most hp gain?

 

A lot of people go with the K&N filter but it's not close to a 12hp gain.

 

agree with above, i do not believe you will see 12 hp from a filter, hp can be gain by adding displacement, or head job, motor work, etc. obviously the more work you have done, the more the filter has a factor...

 

I think the important word here is "system" in that K&Ns advertising up to a 12HP gain is not about changing just the filter but the claim is made when you remove the OEM intake assembly and install the K&N intake assembly. It definitely flows much more air than stock and (using the air pump analogy) lets your engine produce more power and is typically referred to as "Stage 1" when you do three basic things - provide a freer flowing exhaust, let more air "in" and add a bit of fuel to the increased amount of air. This minor modification "package" is probably the cheapest horsepower you'll ever add to your big twin.