the flyin' scotsman

If this is accurate then the arrows do point up................toward the upper housing, the hood and against the direction of air flow...............correct?

My paper filter was procured from 928 specialists, has made in Austria stamped at one end with arrows and the same end. I also looked at my K&N filter that I no longer use...............no arrows, no up or down marks, only the K&N logo and part number which I assume is the 'up' side of the filter.

Dennis Wilson

Made in Australia? No wonder the arrow is pointing in the wrong direction. If the arrow points toward the side with ridges, you are right, it probably means up/top/oben.

Dennis

worf928

Either there is misunderstanding or disagreement or the Porsche-branded filters have 'Oben' on the wrong side!

I just went and double-checked one of my Porsche filters and yes 'oben' is printed on the face of the filter that extends from the filter frame. The side that is flush with the filter frame is down towards the MAS. Thus the 'fat' face, or the face that sticks 'out' from the filter is the top and faces up.

Unless the Porsche filters are stamped incorrectly.

worf928

IMO Yes.

BUT, it may depend upon the manufacturer. As I wrote in my first post: David Lloyd and I compared notes and we've seen the non-Porsche filters either way.

the flyin' scotsman

Too funny

I guess its to simple for all the manufacturers to have one orientation stamped on the filters.................up, oben or otherwise.

Its -1C so no worries for some time...............appreciate the input

ew928

Okay. Guess I'm bored.
First pic with the part sticking out. (Top I presume)




Second with the flush side facing up.




Did I get it right?
Same Microstar LX311.
No arrow. No "Oben".
Running a MAF killer ill-fitting air filter in the car right now.
The MAF Killer has no flush surface so it just sits wrong in the filter box.

Ernest (NYC)

the flyin' scotsman

Very bored also.............#1 pic is up..........I think, where's the arrows?

worf928

Ernest, you really are bored.

Yes. IMO, the first pic is up.

If you are bored and wealthy, I will go take a picture of my oFFcIAL Porsche filter - but you will have to buy me a beer or three the next time you see me (that's where the wealthy part comes in) since I will have to put on shoes, socks, coat, dig out the camera, and venture out into the cold garage (hence why I would want payment. )

worf928

Oh, and THIS thread should be proof that NO 928-related question is stupid (or simple.)

ew928

Most of the time, I can't find a thing at home if I hadn't seen it a while.
Why is it that I know exactly where the neglected 928 paper filter is at home.

If you guys hadn't brought this up, I would never had realized that the 928 air filter
was designed with a true top and bottom haven't dealt with the symmetrical reusable MAF-killer filter for so long.

Wonder if the official filter, with it's filter element located further from the MAF screen than the reusable filter, does produce a measurable difference at the dyno.
The denser folds of the paper elements and it's higher placement would differentially soothe the airstream as it tumbles in from the 2 intake tubes. Just speculating.

Of course I'll leave the controversial later style filter box metal latch fastening alone.
Metal latch over wire loop or wire loop over metal latch.

Ernest (NYC)

whiteNSXs

Reviving an old thread. I was looking at my air box. Apparently, the last person who put in the air filter got it wrong so the fitting is quite poor. There are 2 surfaces of the filter. One flat and one curved. The arrows point to the curved side. So the last guy installed the air filter with the arrow pointing UPWARDS with the CURVED side facing UP. WRONG ORIENTATION!!!! The FLAT side should face UP and the CURVED side should face DOWN. The arrows point to the DIRECTION of the AIR FLOW so the arrows should be pointing DOWN.
All the straps are kind of worn so I will need to renew all 4 straps. Where do I get the best price for them?
Steve

GlenL

Curved side is up

whiteNSXs

I don't think so. With all my other Porsche Carreras, NSXs, and Hondas, ALL the air filters have the curved sides facing towards the engine and the flat sides facing the air inlet side.
Steve

worf928

If it makes you feel better to run your air filter upside down and to choke-off air to the mass-air sensor, and to run the air filter in an orientation contrary to the German-language printing that appears on an actual Porsche filter then by all means do so.

You are however, still, quite wrong.

Mrmerlin

Pay no attention to the arrows stamped on the sides of the 928 filter they are for packaging when the filter is made..
( I have seen arrows that point in both directions on different filters)
So a little bit of common sense is required here......

On a 928, The filter has 2 sides , with the filter sitting on a flat surface the raised part is the the side thats facing the incoming air, the flat part faces the MAF/ throttle body.
Note, This Only applies to the 928 air filter housing.


Steve if the filter that you have fitted ( in any of your other cars) can be installed so that a raised portion of it faces away from the throttle housing then you should install it this way, it will increase the air box volume.
Once a filter has been installed it is not a wise idea to try to clean it so it can be turned around. as fine particles will be sucked into the engine.
Replace the filter and install it the correct way.

That said there are some filters that will only fit one way and are in fact made to fit one way as in the bigger or raised side faces the throttle, in that case install the filter the way it fits best into the air cleaner housing

BUT for a 928 the filter should be sticking up when you fit the top cover of the air cleaner housing