K&N without modified exhaust ....worthwhile?

[mikep]

I see many posts and UOA mentioning the use of K&N or similar "high performance", "high flow" air filters. Many of these vehicles are otherwise bone stock. I have to wonder if there is any real benefit to using just an aftermarket filter? Obviously it should allow for a greater volume of air available but without other modifications to increase available fuel and a way to move that air along and out (exhaust), will the motor really make use of it? In order to fully take advantage of an increase in airflow in, wouldn't the throttle body, MAF and exhaust also need to be addressed? Am I totally off base with the other elements of the intake/exhaust path?

Even if there were a slight increase in performance with just the filter is it really worth the hassle of increased silicon and dust/dirt particles? It seems there is often an increase in engine wear that seem to show up in so many UOA with these filters in use? Not to mention the possibility of employing the "more is better" philosphophy when oiling the filter element thus fouling the mass airflow sensor.

Please, nobody take my query the wrong way. My intent is not to knock anyone who uses these filters but instead to understand why and how and with what expectations. Lord knows they are very popular which is why I'm asking questions. There must be something to these things with so many people using them.

 

[T-Keith]

Depends on the car. Some cars can benefit from an air filter change. My 3.8 had a ridiculously small air filter and a power change was immediately obvious. Other cars may not see a noticeable improvement.

The reason a lot of people go with K&Ns or similar filters is to replace the air box with an CAI or better flowing intake system. No paper company supports this, so a cotton gauze cone filter is usually the way to go.

-T

 

[Dan4510]

Mike,

These filters can be useful in adding output if and its a big "if" the factory filter is too small.

There are usually other things that limit flow before the the air filter does. It can be restrictive tubing to the intake side of the engine, it can be the throttle body itself. If the filter flows 1000cfm and the throttle body will only flow 300cfm, no way that the air filter will do any good.

Do a search on the board and you will turn up many threads that discuss this in detail.

Dan