Without any other variables to consider (same brand/octane gas, same oil, same driving style, what else could it be?

It's noticable on my 911 turbo as well as my 928 (pre-turbo). I'm not the first to report this either.

The K&N poses no issue. I've had one on my Audi S4 for 150,000 miles and that is a draw thru straight to the MAF (same MAF style as the 928 uses). On the twin turbo I draw in thru the filters and then thru the turbos, past the intercoolers and then past the hotwire...again no problems on this system with over 12,000 miles on the system now. My intake is BONE DRY on the 32V twin turbo. There has never been a drop of oil anywhere in the intake system, not from the filters or the turbochargers.

You don't need excessive oil on them to make them work.

There are many myths out there and I believe this is one of them. Just like the myth that turbos don't work on a 928...that wasn't true either.

Naah, it's fact. Just like this:
http://lilymichaud.files.wordpress.c...09/unicorn.jpg

Mule you got me wrong.

I have a K&N on my turbo 928: I'm not against them, they work well, better on some cars than on others, though I've noticed darker (dirtier) oil mostly in my 911 turbo when i ran the K&N vs a factory filter, that's all.

I'm merely stating an observation: Maybe I imagined it, but I remember black oil (K&N) vs brown (Mahle) at roughly the same time/mileage interval.

how true this basic comment is------;)


--Russ

perhaps you could run a test with your cars using the two different filters......

run the Mahle for a certain interval, change the oil and pull an oil sample for testing, then run the K&N the same number of miles, change the oil and pull a sample for testing.

compare the test results and then you can make an "informed" decision about your filters and their affects on your engine oil.

Holt Caterpillar in Austin has oil sample kits for relatively low cost (less than $15).

Check it out-----

--Russ

Mule, is that Stallion Turbocharged? Man-Bear-Pig would approve!

I think that's Manbearpig's actual ride.... :cool:

I agree that a fresh out of a box K&N won't cause a MAF problem. I've had one on my car for several years.

But I don't recommend them as over oiling can dump more oil on the hot wire than it can burn off. The additional oil can then be burnt onto the wire.

Maybe a carb/MAF cleaner will help in those cases. I see quite a few MAF saturated in oil, but suspect they are from oil burning engines blowing lots of oil back up the intake.

On a stock 928 I don't believe the K&N has any performance benefit.

It's an extremely high tech, new design located in the horn.

It was for a while. Algore told MBP that it's methane gas emissons were too high, so MBP is back on foot errr hoof.

From what I know, oil is discolored by combustion by products. If a situation exists where so much dirt is in the cylinder that it is somehow finding it's way into the oil, my guess is that you will need an overhaul soon.

I think it would take an 87 or later to see a noticeable performance change.

The air filter isn't for keeping the oil clean, its for keeping abrasive particles out of the engine wear areas. Most of anything going in with the air I suspect goes out with the exhaust, but some is bound to end up in the ring area, and thats bad.

That's all we need around here...a horney manbearpig turbocharger.

The factory filter area is huge, and is dome shaped to allow more room under the filter for better airflow into the AFM/MAF.

The K&N doesn't fit properly, and usually leaks at the edges. It is flat, and taller, so it takes up more room in the airbox.

My S³ made 312 rwhp SAE with the stock filter, airbox, and the smaller 85-86 air tubes. (Taking the airbox lid off leaned out the A/F ratio and it made 316.)

[img]http://www.***********************/images/product_images/images/WORLDPAC/W01331624373MAH.JPG[/img]

That appears to say that a freer flowing K&N should make more power, especially in an '87 or newer.

Mark Kibort did some testing with a sensitive pressure meter using a long thin sample tube that allowed measurements at various stages of the intake system right down to valves almost.

For best results, get rid of the whole silly filter box, and supply cool air.

No surprise there. Herr Kuhn's system is sweet. So's Dave Roberts' but the cost is steep for the power increase. Next best bet, stock system with a K&N.

I've used K&N filters for years and didn't have any problems until I over-oiled one, which ended up ruining the MAF on one of my cars (not the 928). My experience leaves me with the impression that K&N filters are fine when new out of the box, but can be troublesome if they are over-oiled. I know a few folks that buy a new K&N filter when it needs replacing as they don't want to risk ruining their MAF.

I removed only the airbox lid, not the stock filter. This leaned out the A/F ratio, and gave a higher HP number, but torque went down. (Best numbers come with a rich mid-range for TQ, and lean at high rpm for HP.) The lower A/F ratio may only have been from turbulence into the MAF because of the lid missing, or hotter air from around the engine, not an increase in airflow.