Just Installed K&N Filters
#31
05-23-2008, 04:25 PM
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#32
05-23-2008, 05:03 PM
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#33
05-24-2008, 03:45 PM
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Nissan dealer wants $20 for one filter.... where can I buy pair for $20? Thanks....
I think nissan and infiniti have the same part, maybe its cheaper at nissan dealer.
I decided to put back the old stock filters, there's 10K miles on them so i guess i still have 5K miles to go but man they look black dusty nasty dirty, like lung cancer patient! Must be the heavenly los angeles air quality.
I think nissan and infiniti have the same part, maybe its cheaper at nissan dealer.
I decided to put back the old stock filters, there's 10K miles on them so i guess i still have 5K miles to go but man they look black dusty nasty dirty, like lung cancer patient! Must be the heavenly los angeles air quality.
Last edited by oughttoreturn; 05-24-2008 at 03:50 PM.
#34
05-24-2008, 04:09 PM
Originally Posted by oughttoreturn
Nissan dealer wants $20 for one filter.... where can I buy pair for $20? Thanks....
I think nissan and infiniti have the same part, maybe its cheaper at nissan dealer.
I decided to put back the old stock filters, there's 10K miles on them so i guess i still have 5K miles to go but man they look black dusty nasty dirty, like lung cancer patient! Must be the heavenly los angeles air quality.
I think nissan and infiniti have the same part, maybe its cheaper at nissan dealer.
I decided to put back the old stock filters, there's 10K miles on them so i guess i still have 5K miles to go but man they look black dusty nasty dirty, like lung cancer patient! Must be the heavenly los angeles air quality.
#35
05-24-2008, 05:00 PM
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#36
05-24-2008, 06:44 PM
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Originally Posted by oughttoreturn
Nissan dealer wants $20 for one filter.... where can I buy pair for $20? Thanks....
I think nissan and infiniti have the same part, maybe its cheaper at nissan dealer.
I decided to put back the old stock filters, there's 10K miles on them so i guess i still have 5K miles to go but man they look black dusty nasty dirty, like lung cancer patient! Must be the heavenly los angeles air quality.
I think nissan and infiniti have the same part, maybe its cheaper at nissan dealer.
I decided to put back the old stock filters, there's 10K miles on them so i guess i still have 5K miles to go but man they look black dusty nasty dirty, like lung cancer patient! Must be the heavenly los angeles air quality.
I believe the recommended replacement interval for the engine filters is 30k. The cabin filter is 15k. But if your filters are already that dirty then...
Last edited by CalsonicVQ; 05-24-2008 at 06:49 PM.
#41
05-24-2008, 11:12 PM
I installed k+n drop ins along with z-tube so I did notice minimal improvement in throttle response and gas mileage. I would like some evidence that k+n filters are not as efficient as oem in cleaning intake charge. Like someone stated before, im sure k&n manufacrtures filters for automakers, I am absolutelty sure they make the air filters for the ah-64d, apache helicopter, because I was aviation in army and actually held one in my hand. With as long as they been around I would expect k+n to have r&d a superior air filter. With as much as they cost Im sure if k&n wasnt a more efficient air filters there would be a hell of alot of complaining and they would have bad rep. in all the motorsports world.
#42
05-24-2008, 11:29 PM
http://www.bobistheoilguy.com/airfilter/airtest3.htm
also, regarding airflow:
"So what do these results mean? For one, there is very little pressure drop across any air filter, and the difference between the best (K&N) and worst (paper) is very small. Yes as total power output increases, air flow increases, and differential pressure would also increase. So a K&N probably does yield some power on higher output race motors where every last ounce of power must be squeezed out. On lower powered street cars, it is probably not much of an improvement over paper. Basically, an air filter is first and foremost a filter, and should be chosen for it's filtration ability. I know after this enlightening experiment, that is exactly how I will select my air filters. Also remember, that this total differential pressure is measured from the atmosphere via the stock Miata air intake tube, airbox, accross the filter, though the test port, about 6 feet of tygon tubing and the manometer and back to the atmosphere. This is not the pressure drop across the filter itself. I may do a quick test with no filter ( I really hate to do it, but might anyway) to get a good estimate of how much is the system itself sans the filter.
For this test differential pressure for the Napa filter is lower due to different atmospheric conditions (different day) and 500 less rpm at the data collection point. That said, it is still noteworthy that the Baldwin and Mazda filter do not flow as well as the Napa, but are still very, very close. In all honestly, all 3 flow about the same or very nearly the same. So it is safe to say from the first test, that the K&N is still the best flowing filter. What is interesting to note is that there was a 5.1 inch of H2O differential pressure in the stock air box and intake piping. If you subtract this different it says worst case one can see a 2 inch of H2O differential pressure loss due to the air filter. This is equivalent to 0.072 psi or very nearly nothing. The air filter posses very little restriction at all in this application. As long as an air filter is properly sized for an application, the lost airflow will be very minimal. This means that there is very little if any power to be found from removing the air filter, much less changing the filter type. The K&N did flow better than the Napa Gold in the first test to the tune of 0.02 psi. That is less than 1/3rd the loss in the factory piping, and it is a whopping 0.14% of atmospheric pressure (14.7 psi). If you need the 0.14% better airflow, than the K&N is hands down the best filter. "
also, regarding airflow:
"So what do these results mean? For one, there is very little pressure drop across any air filter, and the difference between the best (K&N) and worst (paper) is very small. Yes as total power output increases, air flow increases, and differential pressure would also increase. So a K&N probably does yield some power on higher output race motors where every last ounce of power must be squeezed out. On lower powered street cars, it is probably not much of an improvement over paper. Basically, an air filter is first and foremost a filter, and should be chosen for it's filtration ability. I know after this enlightening experiment, that is exactly how I will select my air filters. Also remember, that this total differential pressure is measured from the atmosphere via the stock Miata air intake tube, airbox, accross the filter, though the test port, about 6 feet of tygon tubing and the manometer and back to the atmosphere. This is not the pressure drop across the filter itself. I may do a quick test with no filter ( I really hate to do it, but might anyway) to get a good estimate of how much is the system itself sans the filter.
For this test differential pressure for the Napa filter is lower due to different atmospheric conditions (different day) and 500 less rpm at the data collection point. That said, it is still noteworthy that the Baldwin and Mazda filter do not flow as well as the Napa, but are still very, very close. In all honestly, all 3 flow about the same or very nearly the same. So it is safe to say from the first test, that the K&N is still the best flowing filter. What is interesting to note is that there was a 5.1 inch of H2O differential pressure in the stock air box and intake piping. If you subtract this different it says worst case one can see a 2 inch of H2O differential pressure loss due to the air filter. This is equivalent to 0.072 psi or very nearly nothing. The air filter posses very little restriction at all in this application. As long as an air filter is properly sized for an application, the lost airflow will be very minimal. This means that there is very little if any power to be found from removing the air filter, much less changing the filter type. The K&N did flow better than the Napa Gold in the first test to the tune of 0.02 psi. That is less than 1/3rd the loss in the factory piping, and it is a whopping 0.14% of atmospheric pressure (14.7 psi). If you need the 0.14% better airflow, than the K&N is hands down the best filter. "
Last edited by mal_TX; 05-24-2008 at 11:33 PM.
#45
05-26-2008, 02:56 PM
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Originally Posted by Wes_888
So in other words, K&N filters are better than regular OEM filters? If I understood correct?
they do absolutely nothing appreciable. you net zero gains worth talking about and it's damn near the worst dollar/gain mod you can do. *sigh*
aaaanyway... what makes injen better? nothing at the moment. they're the only folks showing any real gains on their dyno runs, though. the stock setup is pretty well matched for the motor so it's hard to improve just by tossing tubes and cones on