K&N air filters
07-26-2002, 06:05 PM
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K&N air filters
Do you recommend K&N air filters on a stock '82 sc? I read a thread on enhanced performance a while back where someone wrote that they use a K&N air filter when at the track the change back to a stock one for around town. Any reason why they would not leave it in all the time? Thanks in advance, Kevin
07-26-2002, 06:19 PM
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Kevin,
Advertising aside, there's not a solid case to use anybody else's filters. I saw one study that suggested that K&N-type filters actually let more dirt/dust particles into the engine than stock filters. The Porsche filters are actually pretty good. If you want more hp on your SC, put SSI heat exchangers on with a good muffler.
Advertising aside, there's not a solid case to use anybody else's filters. I saw one study that suggested that K&N-type filters actually let more dirt/dust particles into the engine than stock filters. The Porsche filters are actually pretty good. If you want more hp on your SC, put SSI heat exchangers on with a good muffler.
07-26-2002, 07:13 PM
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I bought into the K&N hype. It didn't do anything that I can tell, but I sure love the extra room in the engine area. I can reach things back there a lot more easily now. I'm putting on a test pipe tomorrow, so maybe that will optimize the K&N.
07-27-2002, 11:33 AM
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I use the K&N on my 83SC and have done the dyno tests to prove that it does give you an average of 7 HP.I regularly check inside my airbox and I do not find any more or less dirt or dust than with the stock filter.I have used the K&N for about 4 years and I just turned over 237,000 miles on my daily driver SC.
07-27-2002, 03:52 PM
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I had a K&N on my car but the engineer in me told me it made no sense so I installed a paper elemnt.
Why:
1-The air needs to come into the air box through to small opening at the end of the snout which has much less cross sectional area than the filter media. Given this, the opening of the snout sets the maximum flow. The significantly larger cross section of the media wiil allow all the air to flow through without impedance since pressure drop is proportional to surface area.
2-Normal filters work via impaction where the dust particle "rams into" the filter media and sticks. This is a very effective method for particles down to the single digit micron ranges. Filters that attract smaller (sub micron)particles to their surface require huge cross-sectional areas to slow the air flow to allow the particle to "drift" into the media. These sub micron filters have huge pressure drops as a result.
3-The cost of a paper elemnt around me is about $13. The cost of the K&N cleaner and oil is $6. Givent he effectiveness of the paper elements, I can buy one each year to keep my engine internal clean and not mess with the K&N Hassle.
This said, for cars that the air filter represents a significant restriction to air flow (not a P-car), the K&N will show some improvement at the cost of greater particle entry into you engine (and it's subsequent damage). You can verify this for yourself by driving you car with air filter on, removing it, and driving it again (for just a little while, and see if you see any performance difference.
Why:
1-The air needs to come into the air box through to small opening at the end of the snout which has much less cross sectional area than the filter media. Given this, the opening of the snout sets the maximum flow. The significantly larger cross section of the media wiil allow all the air to flow through without impedance since pressure drop is proportional to surface area.
2-Normal filters work via impaction where the dust particle "rams into" the filter media and sticks. This is a very effective method for particles down to the single digit micron ranges. Filters that attract smaller (sub micron)particles to their surface require huge cross-sectional areas to slow the air flow to allow the particle to "drift" into the media. These sub micron filters have huge pressure drops as a result.
3-The cost of a paper elemnt around me is about $13. The cost of the K&N cleaner and oil is $6. Givent he effectiveness of the paper elements, I can buy one each year to keep my engine internal clean and not mess with the K&N Hassle.
This said, for cars that the air filter represents a significant restriction to air flow (not a P-car), the K&N will show some improvement at the cost of greater particle entry into you engine (and it's subsequent damage). You can verify this for yourself by driving you car with air filter on, removing it, and driving it again (for just a little while, and see if you see any performance difference.
07-28-2002, 02:58 PM
#6
It was interesting to read Chuck's dyno results- those are the first 'documented' improvements I've heard about - all the others have been purely anecdotal. Reading the hype of the K&N box, it makes it sound like they're the greatest things since sliced bread and zippers.
3 questions:
1.- Harry D.- for a while people were drilling holes in their airboxes for alleged improved performance. Wouldn't having these extra holes provide the additional air access you concluded was missing from the OEM opening?
2.- Rather than any real HP increase, could the use of the K&N improve throttle response?
3.- would the drilled airbox do anything to improve throttle response?
TIA
3 questions:
1.- Harry D.- for a while people were drilling holes in their airboxes for alleged improved performance. Wouldn't having these extra holes provide the additional air access you concluded was missing from the OEM opening?
2.- Rather than any real HP increase, could the use of the K&N improve throttle response?
3.- would the drilled airbox do anything to improve throttle response?
TIA
07-28-2002, 05:29 PM
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John D,
I think to folks drilling holes did improve air flow but that was engines with larger displacements than mine. You would know if this helps if you remove the air filter cover and your power seems to increase.
I think to folks drilling holes did improve air flow but that was engines with larger displacements than mine. You would know if this helps if you remove the air filter cover and your power seems to increase.
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07-30-2002, 11:59 PM
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[quote]Originally posted by Chuck Harmon:
<strong>I use the K&N on my 83SC and have done the dyno tests to prove that it does give you an average of 7 HP.I regularly check inside my airbox and I do not find any more or less dirt or dust than with the stock filter.I have used the K&N for about 4 years and I just turned over 237,000 miles on my daily driver SC.</strong><hr></blockquote>
Did you prove it by doing before and after tests or just after? Bruce A's test showed no difference and other's have reported a small loss. I've read that just removing the filter completely caused a small loss (4hp).
thanks,
Chris
<strong>I use the K&N on my 83SC and have done the dyno tests to prove that it does give you an average of 7 HP.I regularly check inside my airbox and I do not find any more or less dirt or dust than with the stock filter.I have used the K&N for about 4 years and I just turned over 237,000 miles on my daily driver SC.</strong><hr></blockquote>
Did you prove it by doing before and after tests or just after? Bruce A's test showed no difference and other's have reported a small loss. I've read that just removing the filter completely caused a small loss (4hp).
thanks,
Chris
07-31-2002, 11:07 AM
#9
I haven't installed a K&N in my '88 Carrera yet, but I intend to, based on my experience with other cars. I've used them on Saab Turbos for years and always motice an increase in power, especially on my '00 Saab 9-3 (which is a turbo). The power increase was immediately noticeable and significant (seat-of-the-pants dyno). I used one on an '84 Saab Turbo, and drove it for 217K miles without any internal engine problems or oil use, so I don't think there's any dirt getting past these filters. The intake tracts on the engine side of the filters always appear to be spotless.
