intake systems

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07-09-2007, 11:01 AM

#16

Ed Burdell

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Quote:

Originally Posted by Pan58

Jeff that is my plan at this point is to buy a used lid and modify it like the cup car design and see how it goes, plus either a K&N (lightly oiled)...

Didn't someone here say that the oil from the air filter would eventually make the mass air sensor fail?

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07-09-2007, 11:51 AM

#17

Mark in Baltimore

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Quote:

Originally Posted by TargaTango

Mark, Exactly what I thought when I read this thread but I am not sure it is that simple. Check out this thread which I am wading through:

https://rennlist.com/forums/showthre...ferrerid=26865

All the best,

Thanks for the link, Chris! Lots of posts to wade through.

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07-09-2007, 12:21 PM

#18

JasonAndreas

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Quote:

Originally Posted by Ed Burdell

Didn't someone here say that the oil from the air filter would eventually make the mass air sensor fail?

The 993 MAF uses a HOT-WIRE that is heated up to a "burn-off" temperature (1000°C) for one second after the engine is switched off. This vaporizes and/or splits off the deposits (oil, etc.) and cleans the wire. The 996 and newer Porsches use a HOT-FILM that in theory does not require a burn-off. The theory part being that the contaminants collect on the leading edge of whatever is sitting in the air stream and the sensor element is protected/surrounded by a metal. This works for the most part but not perfectly so Porsche had Bosch redesign the airstream path (1st image) inside the sensor for MY02 (2nd image). Manually cleaning the newer 996 hot-film style MAF still makes noticeable improvement. So an oily air filter is not as big of a problem for the 993 as it is for the 996. Any sensor drift is usually taken care of after you turn off the engine and eventually you won't be sucking in oil but it can still be a minor issue. The thing is there are no benefits financially or performance wise to running a K&N filter in a 993. You can buy an OE air filter from a Porsche dealer for $15.67USD and you replace them every 15k miles. For the price of a single K&N and the cleaning & oil solution you can buy quite a number of OE air filters.

MY99-01 MAF air path

MY02 MAF air path

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07-09-2007, 12:49 PM

#19

jimbo3

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Quote:

Originally Posted by DJF1

Not so with the 993 air cooled engine. Over the years there have been many that tried, ALL unsuccessful. K&N cone filters literally fell apart when installed in the 993 engine bay a few years back...
A 911 engine is not your typical detroit iron. The air flow in conjunction with the stock ECU is optimized already. What any aircooled engine needs is cooler air. Both systems that you linked will draw hot air in abundance and you will loose power. The most effective add on, if you have an RS tail or any other fixed tail, is the RS snorkel, a $10 part that connects to the end of the stock airbox and draws fresh air from below the wing.
If you want more power you need more dollars than a cone filter....

+1. (Actually, +100). If you're looking for HP, modifying a 993 intake will gain zero. OEM filter works best and the MS airbox cover will give you a little nicer sound. Maybe look into a chip and different cats as the lowest cost mod for addtl 10 HP. Or, save your money and put it into a LWF.