To K&n Or Not To K&n.... Air Filters

[jplumlee]

K&N is what I meant to write... Yes, I'm an idiot. No I can't figure out how to change the title :D

I was able to find some older(er) threads on this subject, but not much.

So..... are they all they're cracked up to be? In their continued quest for increased air flow, do they really allow too much gunk through? Is there really any performance gain to be had on a normally aspirated Cayenne V8?

thanks, inquiring minds want to know!

Edited April 26, 2010 by Loren
fixed title

[odix]

A lot of info on this in the threads here on Renntech -- for somewhat minor performance increases you expose your engine to additional wear and tear from particulate matter. Depends on where you'll be doing your driving -- roads, air quality, etc. It's a subjective decision based on cost and pros/cons.

[wvicary]

They are rubbish and not recommended by any manufacturer that I'm aware of.... the only thing good about K&N is their marketing department.

[Loren]

Porsche uses BMC race filters in their race cars. But remember race car engines are rebuilt every after 50 hours of operation.

[wvicary]

Porsche uses BMC race filters in their race cars. But remember race car engines are rebuilt every after 50 hours of operation.

50 hours of operation or less.

Here's the way I look at it, If auto manufacturers spend millions upon millions in R&D to get more output and better fuel milage from their products and all they had to do was install a K&N type filter don't you think they would??

[ManMN]

I agree with your comment about millions spent in R&D, but on the other hand for example, BMW 330 series vs M3, they are about 100hp different by just tweaking the controls. It's all about marketing, if you have more money, you'll pay more.

[number9ine]

I agree with your comment about millions spent in R&D, but on the other hand for example, BMW 330 series vs M3, they are about 100hp different by just tweaking the controls. It's all about marketing, if you have more money, you'll pay more.

Huh? I assume your comment refers to the E46, not the E90 where the difference is two cylinders, among other things. Even on the E46 3-series, the difference is displacement. 100 HP from an NA engine doesn't come without adding cubic inches. All for a few million dollars in R&D, of course.

wvicary is right, and while his comments ring true for many manufacturers they're especially true for Porsche. For example, the M96/M97 range of engines might be built on many similar parts, but the differences in performance are all accomplished with significant modification to displacement, internals, accessories, and the like. Even the N/A Powerkit engines rely on some serious, expensive internal and external part swaps to make all of 30 horsepower and a dollop more torque. The engine/model differences may be conceived as a marketing excercise, but their execution is wholly dependant on hours and dollars of mechanical engineering, not a "control tweak."

An aftermarket air filter or exhaust accomplishes three things in my mind: 1) a waste of money due to no significant performance gain, 2) the risk of upsetting the delicate balance between engine systems tuned by some of the best engineering minds on the planet, and 3) on-and off-throttle noise that sounds more Tokyo than Stuttgart. Note that 3) is the only measurable benefit, which I think any aftermarket shopper should balance against cost and reliability. Hell, Porsche makes loud bits for their cars that cost a lot of money--see PSE, motorsound, etc. Porsche's items don't come with dubious claims of extra power.

My advice? Take that money and enroll in a PCA driver education weekend. A few of those, and you'll feel a LOT faster in everything you drive. If you want noise, roll the window down or make motor sounds like the kids do when they imagine driving these wonderful cars.

Mark