The K&N filter costs a,little more than a stock one but it is reusable after cleaning. So even if there is no improvement in performance, is is cheaper in the long run.

From what I've read (and as described by Zed Head above) the K&N filters are much less effective than the traditional paper alternatives. If that's the case, it would be a lot cheaper to replace your paper filter a whole bunch of times rather than pay for an engine rebuild because your rings or cylinder walls are worn.

 

I'm no filter expert. Have you researched any effectiveness comparisons?

Full disclosure - I have one of the flat K&N filters on my Pathfinder.  There is a certain freeway hill nearby that I take on a regular basis and I wanted to see if I could get an extra HP or two to help haul the SUV's mass up the hill without having to shift down in to fourth.  It seemed to help so I left it in there.  The engine is high mileage anyway so the extra dirt probably just slides by the rings in to the crankcase for the oil filter to clear out.

I have the K&N stock replacement filter in my 240Z. (Stock air cleaner) The paper filters are not available locally, so I bought it for convenience. It is almost never dusty here in Indiana, so long as you stay on the PAVED roads. (The sole benefit of living in what was once a swamp) Except for bugs and pollen there isn't much to filter out of the air around here. And since I seldom drive the car 6000 miles a year, I am not that worried about filter efficiency.

  On 12/2/2014 at 2:00 AM, Captain Obvious said:

Hahaha!! ::

 

Is that all you got? I had vultures storing carrion in mine!!

Carrion?  Vultures were storing their baggage in there and riding in the cabin with you?  

  On 12/2/2014 at 11:11 AM, siteunseen said:

Carrion?  Vultures were storing their baggage in there and riding in the cabin with you?  

Haha! And I thought I was bad... 

A little off topic, but IMO the main thing is to change or clean the filters frequently. A few years back, a friend had a 90's Nissan SUV that was running crappy. A "mechanic" had done some stuff and charged him money, but he still couldn't keep up with traffic on the freeway. We pulled off the air cleaner, shook about a cup of dirt out of it. After that it ran fine.

I have K&N's with the round chrome housings (carbs) and clean and oil them about every six months, always get a fair amount of dirt out of them.

I bought an Exmark commercial mower a few years ago.  At the end of the season, getting leaves up it would die when I tried to engage the blades.  Scared I'd torn it up already I carried it to where I bought it, they put a new air filter in and I've blown it out once a month since then.  It's ran without any problems ever since.  *Egg on my face emoticon*

Exmark! 

 

 

 

  On 11/30/2014 at 3:30 AM, Michael said:

I would like to purchase and install a cold air intake for my 1975 280Z which is currently stock.  I was hoping someone would have experience with this kind of bolt-on upgrade and whether it was worth it and also if they could recommend the best manufacturer out of the many choices out there.  

There aren't any "cold air intakes" that you can buy.  People have tried making them with different kinds of tubes, support brackets, and a cone filter. No one has mentioned if there is any kind of improvement. As with most things on the L28 engine, there isn't any such thing as an "upgrade."

I think that when you're making "upgrades" you should start with the largest contributors to performance and work down the priority list from there. The problem is that things like cold air intakes are almost always starting from the wrong end of the spectrum. Pulling warm engine compartment air is not a significant detriment to your Z cars performance. Neither is the pressure drop across your paper air filter. Not until you've spent lots of money on your engine first.

 

After you've done a bunch of engine and carb upgrades, THEN maybe you might want to turn your attention to something like a cold air intake. But with a stock or mostly stock engine? Nothing to be gained.

 

How much time do you spend at WOT anyway...???