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Hey guys Post #103..what did I miss??? LOL...
I use a K & N Filter and clean it yearly (before Hershey, +/- 3,000 miles)...I like it...
YMMV,
Jay
“Faster, Faster, until the thrill of speed overcomes the fear of death.” - Hunter S. Thompson
"I couldn't find the sports car of my dreams, so I built it myself." ~Dr. Ferdinand Porsche
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So from reading this thread I guess the majority conclusions are:
1) The HP gains from running a K&N are significant
2) The grit passed on by the K&N filter, while significant, is not causing significant wear
As for the first, the claims seem unrealistic. And how many unbiased tests are out there? A magazine or website supported by advertising, some of which is for companies that sell performance parts, is not really unbiased. K&N, obviously, is not unbiased. Some performance gain is expected but as the overall restriction from a typical paper filter in a properly-sized airbox is quite small, cutting that restriction even in half is not likely to result in significant gains. I understand some people think there is something not-understood at work that allows for these gains and that is somewhat possible (a possibility is that an open-loop system running a bit leaner at WOT.) Overall I think the gains are overstated as they usually are when car parts and money come together.
As for the second point , I think the grit is significant and while in my tenure as an owner of any given car it might not add up to much, it still bothers me. Having torn down a lot of dirtbike engines I have seen what bores can look like after eating a lot of dirt and dust and still run quite strong. The fact that it is possible to eat a lot of dust and still make good power does not mean I am OK with doing it. I've seen the holes in K&N filters, I've seen the grit they pass. Even if there is 5hp on the table it's not enough IMO. You might think differently and that is your right.
-Joel.
Joel Frahm
1992 968 Cabrio Black/Cashmere
1994 968 Cabrio Iris Blue/Lt. Grey - Supercharged
1987 928S4 Diamondblau/Blue
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" i think the debate only goes on amongst guys who are too cheap to pop for the K&N"
Well I think there are three of them on the shelf in my garage that I have removed from cars I have purchased. I did not care to run grit through the engines, so I swtched them back to stock. So it's not always cheapness. Perhaps there are no real-world complications but I'm just not comfortable with what I have found thus far.
Joel Frahm
1992 968 Cabrio Black/Cashmere
1994 968 Cabrio Iris Blue/Lt. Grey - Supercharged
1987 928S4 Diamondblau/Blue
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"he had the entire top of my engine in separate parts sitting on his work benches, in addition to showing me how incredibly clean the intake valve spaces were, as well as the entire surrounding exposed area were for that matter, he also mentioned that the intake manifold was so clean you "could eat off of it""
That's the result of all the grit you pulled through the engine, it sand blasted the intake valves and other interior spaces LOL [img]style_emoticons/<#EMO_DIR#>/laugh.gif[/img] [img]style_emoticons/<#EMO_DIR#>/laugh.gif[/img] [img]style_emoticons/<#EMO_DIR#>/laugh.gif[/img] [img]style_emoticons/<#EMO_DIR#>/laugh.gif[/img]
Chris Vais
1994 Coupe Midnight Blue Metallic
2015 Audi Allroad Quattro Brilliant Black
2008 Audi A5 Brilliant Black
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It's not like you are going to find mud and dirt and dust bunnies in there but more particles will pass through. Perhaps not enough to matter at all in the service life of the engine. Maybe it's like the volcano, yes some dust is in the air but enough to measure? and does it matter?
If you want some laughs put a smear of axle grease or a shot of K&N oil in your airbox on the clean side and see how gritty it gets after a few thousand miles. On my FJ1200 I was amazed at how much grit I found in the intake tracts, the PO had fitted K&N pod filters and I serviced them a few times.
My general impression is that they do not produce enough of a gain to warrant messing with. One day I will try to give them a fair test as I have the filters for 968 and 928 on the shelf and all the cleaning/oiling supplies... I think I might have one in the Duc too, I do not recall. It'd be hard to test on that platform though.
My SC car has a K&N also but there might not be an easy alternative. Low priority. I plan to move the MAF under the header in that car so I might look for a different filter at some point.
-J.
Joel Frahm
1992 968 Cabrio Black/Cashmere
1994 968 Cabrio Iris Blue/Lt. Grey - Supercharged
1987 928S4 Diamondblau/Blue