Asiandude

Thinking about fitting a K&N air filter to my '87 S4 auto, nothing strange about that I guess, but will the filter oil damage my MAF element? Anyone using this type of filter with the LH system - good or bad idea?
Appreciate your input.
Joe.

jon928se

Well I've had one on my 88SE for the last 9 years and there was one on my 90GT when we got it 5 years ago. No harmful effects noticed yet but they're not over oiled. And both MAFS have been rebuilt within the last 15k miles average

When I last looked John Speake (JDS Porsche) had one on his 86, but as the MAF rebuilder extraordinaire I guess he doesn't really care.

Asiandude

Sounds reassuring Jon, my car has only done 14K since new (and nine of those in the last year) so I'm hoping the MAF will last a few more years.
Thanks
Joe

Marine Blue

Not sure it will offer any Hp gains, maybe increased noise though.

I've heard that the K&N and other aftermarket filters allow fine silica past the filter and into the engine. This was noted on several oil analysis reports years ago but I haven't done enough research to verify it.

VehiGAZ

[QUOTE=Asiandude;6756595]will the filter oil damage my MAF element? /QUOTE]

This is an admittedly weak answer, but it depends on the car...

I had a Honda Prelude SH with a K&N on it for 100k miles with out a problem. I put one on my Isuzu and fried the MAF in 2-3 months. I won't go back to them though.

Mike Frye

I think the issue with the MAF is a result of overoiling because for us, the stock filter is right above the MAF. Lots of people use them though.


You need this K&N setup!

OBehave

SSSAAAWWWEEETTT!

GlenL

I still have never seen dyno runs of a fresh K&N versus a fresh stock sir filter.

Mike, Any numbers for that rig? Eyeballing, it looks like the filters will have a larger area than a stock filter...and that can matter.

The_Remora

I have nothing against K&N filters in general, but the ones they build for 928's (stock replacement, not Mike's sweet setup or 928Specialist's Blackbird which is awesome) do not fit the filter box well and allow unfiltered air/contaminants to sneak past the filter. Between that and the oiling/MAF issue I would not use a stock replacement one.

Mike Frye

No numbers yet, I just put it on a week ago and at the same time I went with a larger FPR and Porken's new chip setup so it's hard to say if there's any difference. I don't expect to see anything noticeable, but I do plan to test it on a dyno with this setup vs. stock airbox and no other differences in a month or two. I'll post results.

..and thanks for the compliment Chris and Ed. The filter setup is all Kuhn. I just made it fit my car.

Asiandude

I'm amazed at what some of you guys do to your cars - that is a hardcore filter setup!!! When I bought the car a year ago i found the filter element to be installed upside down, that'll be 20 years of grit sucked straight in (thankfully the compressions all seem good) Still like the idea of a K&N though.
Thanks for the opinions guys.
Joe

Mike Frye

I don't think the filter has any kind of 'one way barrier' in there does it? It's just paper and stuff with some tiny holes, right? As long as you don't reverse it, does it matter?

Asiandude

Clean side facing up, dirty side facing toward MAF = not good. The workshops here are capable of this!

Mike Frye

Ah, yeah, that's a problem.

ew928

What's the point of a filter.
To control the size of particles being ingested.

K&N 928 filter. Lets more air though. Maybe.
But last time I looked though a factory 928 filter at a bright light (home light bulb, don't encourage anyone to look at the sun), I see nothing.
Look through a 928 K&N filter, I see many points of light shining through.

Will that 'schticky' oil tack onto incoming particles traveling at speed. Maybe.
For how long till the tack of the oil goes away.
Dunno.