jwillman

So my recently purchased 1979 928 5 spd has a new K&N airfilter installed. I did a search and read a few posts about concerns with the K&N filter affecting MAF because of the oil and mixture because of the increased air but they were older discussions.

Do I need to replace with a stock air filter or if I am okay running the k&N?

Thanks
Jim

Nicole

Since your model doesn't have a MAF, you should be OK with the K&N. Just don't expect any performance gains from it.

jon928se

As Nicole said

You don't have a MAF so no problems.

JHowell37

Any performance gains are a result of it allowing more **** to pass through and into the engine.

VehiGAZ

Oh no he didn't!!!

linderpat

aaaannnd they're off!!!!!

Maleficio

I wished Amsoil made an Ea air filter for the 928. I've never used a better air filter in my life. I've got one in my Volvo XC70. There's nothing better (in my opinion).

http://www.amsoil.com/storefront/eaa.aspx

robot808

ha ha ha, ha ha ha.

RKD in OKC

I used to swear by K&N oiled filters. Put them on everything I owned.

Then I put one on my 90GT. I removed it to clean and re-oil it. Underneath the K&N filter the filter box was coated with a very fine dust. I put a stock filter back in instead of re-oiling the K&N. Haven't used K&N since. Gave away my filter recharge kit.

Just my experience.

docmirror

I just replaced my K&N too. You see, I had put over 140,000 miles on it. That's 140k miles on a truck that does mostly towing duty, and plenty of gravel road work. The intake looked spotless, I just figured the filter had done it's job.

Use it right, make sure there are no leaks, and it'll do the job it was designed for. It's also on my Ferrari with 100,000 miles, and a few other cars.

mark kibort

There are small gains to be had by the KN filter, but it is a hassel to keep it clean and oiled I usually only oil the entry side, which is a trick to keep any contaminants from entering the engine. the KN flows a lot better than the stock filter. one of the BIGGEST issues with testing this with the dyno is the seal of the filter in most air boxes. a more restrictive filter, sometimes will cause the air to bypass the filter at the seal area, and then you get UNfiltered air that enters the intake. anyway, by sealing the air box, using the KN, you get the best flow. for non racing applications, and ease of use, use the stock filter and seal the air box or make sure the air box straps are very tight. Im probably the only one that has really tested this from a flow perspective. (sunx pressure sensors on top of the filter and below the filter during WOT conditions, paper filter , vs KN, and sealed vs compromised sealed tests).
I raced the car for 10 years with a sealed air box and KN. I run at laguna where Ill pull out several ounces of sand after a day on the track from the air filter. yet, pulling the engine, the cylinder walls were perfectly clean with no scratches and the engine was clean as a new engine after not being disassembled for over 20 years!

there is no doubt that the stock air fliter flows less than the KN, BUT, there are other factors to consider, an the extra protection of a stock filter that filters better due to that restriction, might be worth it for you. its all personal preference.

Stromius

Jim you can have mine . I won't be using it in my S4 either.

Brent

Uh ho.

jwillman

Thanks all for the input and education.

Jim

Stromius

Oh snap!