Article on K&N Filters
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8Mud
NAXJA Forum User
- Location
- Central Germany
Bummer TOZOVR, I´ve been lucky, drowned a few. Learned a long time ago, not to try and start them in the water, until I check things out some. When in doubt, pull some plugs and see what comes out (before trying the starter). Much of the damage I´ve seen, done by hydrolock, was done by the starter, more torque than you´d think. The worst damage, I´ve managed, was a valve that looked like an inside out mushroom, that was a close one.
Reading your posts, is making me want to figure out someplace else to get my air from, quick. I´m still running the stock box, on my new to me 88 XJ. Only a matter of time before I baptize this one also.
Was the starter (tech. inspector) for a local, mud pit for a decade. Saw what worked and what didn´t and what kind of worked. The K&N worked better than the paper, in a stock box, most any kind of open filter was a no go. Drawing air trom the rear of the air box was better, drawing air from the top of the motor, center by the firewall was better yet, drawing air from the passengers compartment, was almost fool proof (worked well for CJ, YJ). Guess a snorkle is the best solution (for the XJ). but I really dont want to do that to my XJ. Ran a roof mounted canister (tractor filter) when I lived in the desert, kind of a snorkle.
Most of the wear I´ve seen in the 4.0 has been, cheap oil or years between oil changes (neglect). Pulled the head off of a 4.0 with a 150,000 miles, most of it´s life with a K&N, had worn mains (run a little to hard on the interstate), but very little ridge, which would probably be a tip off for filter related wear. Ran synthetic oil most of it´s life, with bi-yearly changes.
I personally think, frequent oil changes are more important than a few microns of filtration.
Reading your posts, is making me want to figure out someplace else to get my air from, quick. I´m still running the stock box, on my new to me 88 XJ. Only a matter of time before I baptize this one also.
Was the starter (tech. inspector) for a local, mud pit for a decade. Saw what worked and what didn´t and what kind of worked. The K&N worked better than the paper, in a stock box, most any kind of open filter was a no go. Drawing air trom the rear of the air box was better, drawing air from the top of the motor, center by the firewall was better yet, drawing air from the passengers compartment, was almost fool proof (worked well for CJ, YJ). Guess a snorkle is the best solution (for the XJ). but I really dont want to do that to my XJ. Ran a roof mounted canister (tractor filter) when I lived in the desert, kind of a snorkle.
Most of the wear I´ve seen in the 4.0 has been, cheap oil or years between oil changes (neglect). Pulled the head off of a 4.0 with a 150,000 miles, most of it´s life with a K&N, had worn mains (run a little to hard on the interstate), but very little ridge, which would probably be a tip off for filter related wear. Ran synthetic oil most of it´s life, with bi-yearly changes.
I personally think, frequent oil changes are more important than a few microns of filtration.
Dr. Dyno
NAXJA Forum User
- Location
- Al Ain, UAE
TOZOVR said:Nope, #6 cylinder shot the rod right out the side
He's sporting a 4.6L Stroker now.
Ouch! Maybe now he'll fit a snorkel before he takes his Jeep swimming again.
rockwerks
NAXJA Forum User
- Location
- Chito Beach Resort, WA
Ouch! Maybe now he'll fit a snorkel before he takes his Jeep swimming again.
How about smart enough to not go swimming again
How about smart enough to not go swimming again
i have noticed that every one has said that you dont get a power increase from a k&n. weel to notice a real power increase you all so have to be able to exale the air as fast as you suck it in. i run a better exaust and k&n on the toy and it runns great no problems for over 130,000 miles :angel: just my opinon if you do a k&n do your exhaust too.
8Mud
NAXJA Forum User
- Location
- Central Germany
HP isn´t the only indicator of performance, torque plays a roll as does throttle responce, or the amount of time needed from idle to mid range. HP rarley makes a motor rev faster, most HP increases arn´t even apparent, until mid range up. It´s much more apparent on the four bangers, anything that helps remove restriction, helps to turn over the flywheel/converter quicker, helps reach peak torque a fraction faster. A better indicator would be a timed acceleration, from idle to say 2600-2800 RPM (really helps the four bangers, peak torque 2600 or so). Lower restriction in the airbox, fewer bends in the plumbing, less restriction in the exhaust, helps get the motor into the sweet RPM range a little quicker. Every little bit helps, when fighting inertia, pushing mud,climbing a hill, turning large tires.
SV1CEC
NAXJA Forum User
- Location
- Athens, Greece
Just my 2 Eurocents of contribution:
About two years ago, I was trying to improve the performance of my other truck, a Ssang Yong Musso, which has a 2.0 lt Mercedes engine. Too little power (132 bhp) and too low torque (don't remember the figure by heart) at too high RPMs (4000) for a 4x4.
I had found an additional computer you could piggy-pack on the engine's one, and which allowed you to tune the engine's parameters for advance and fuel delivery. The whole adjustment was done on a dyno, with a computer connected to the piggy-pack ECM. Even though the new ECM provided some increase in power and torque, by altering the spark advance, it had to be removed, due to some wierd, hick-up problem.
Anyway, during those 10 hours spend on the dyno, I had the opportunity to try a K&N filter I had on the truck, compared to the standard air filter and box. At the same time, a new exhaust system was manufactured to increase the overall performance. With all other factors remaining constant, the K&N had absolutely no effect on either the horsepower or the torque. Even combined with a better-flowing exhaust, the increase was marginal. As a result, I returned everything to the original specs.
I would say that unless your truck's inlet system is very poorly designed, any change in that area alone would not improve your performance (at least not by as much as the filter manufacturers want us to believe), without changing the camshaft settings.
Rgds
About two years ago, I was trying to improve the performance of my other truck, a Ssang Yong Musso, which has a 2.0 lt Mercedes engine. Too little power (132 bhp) and too low torque (don't remember the figure by heart) at too high RPMs (4000) for a 4x4.
I had found an additional computer you could piggy-pack on the engine's one, and which allowed you to tune the engine's parameters for advance and fuel delivery. The whole adjustment was done on a dyno, with a computer connected to the piggy-pack ECM. Even though the new ECM provided some increase in power and torque, by altering the spark advance, it had to be removed, due to some wierd, hick-up problem.
Anyway, during those 10 hours spend on the dyno, I had the opportunity to try a K&N filter I had on the truck, compared to the standard air filter and box. At the same time, a new exhaust system was manufactured to increase the overall performance. With all other factors remaining constant, the K&N had absolutely no effect on either the horsepower or the torque. Even combined with a better-flowing exhaust, the increase was marginal. As a result, I returned everything to the original specs.
I would say that unless your truck's inlet system is very poorly designed, any change in that area alone would not improve your performance (at least not by as much as the filter manufacturers want us to believe), without changing the camshaft settings.
Rgds
MudDawg
NAXJA Member #728
- Location
- Central Florida
Very good discussion IMHO...both pro and con...however I would bet that the vehicles that have good engine life with wetted gause filters have a low number of hours of exposure to high dust loads...there are engines (boat motors) that dont run filtration at all...then again the dust problem is largely nonexistant.
Take a close look at the filtration systems used by industrial engines such as semi trucks and dump trucks...if a single stage permanent filter worked as well, they could save hundreds of dollars per vehicle in production costs and much more in maintenance costs over the vehicles life span. My engines use at least 2 stage filtration with the final stage being a high quality, properly sized pleated paper element...but then again it don't look cool like a blue or red chrome capped cone filter
Take a close look at the filtration systems used by industrial engines such as semi trucks and dump trucks...if a single stage permanent filter worked as well, they could save hundreds of dollars per vehicle in production costs and much more in maintenance costs over the vehicles life span. My engines use at least 2 stage filtration with the final stage being a high quality, properly sized pleated paper element...but then again it don't look cool like a blue or red chrome capped cone filter
Maz
NAXJA Forum User
- Location
- LaCanada, CA
first off i do have a magic ass:angel: . i did feel a difference in performance not as in a hp feel but as a smoother accel. i dont just have the fillter i have the hole thing so it's open with a smooth tube from filter to tb. i dont know if there is any hp increase but it has run better sence i put it on
- Location
- Desert Beach So Cal
I pulled my running 88 4.0L at 200,000 miles and performed an inspection before I rebuilt it complete. I purchased the 88 (in September 87) off the delivery truck with the plastic on the windows, with less than 4 miles on the odo. The engine has never injected water (but has spent days running silt beds and sand washes at near-WOT in low range).
The rod and mains were within standard bearing tolerance specifications, but out of round (wear was ~0.0005 more on the thrust side of the journals).
There was near zero ring ridge in the cylinders. The wear taper in the cylinders was ~0.001" (the top bore was greater this amount from the clean bottom of the cylinders). The factory hone cross-hatch was visible through the entire bore.
The lifter gallery was clean. The lifters were all worn ~0.005" on the tappet surface. The cam wear was 0.0005" or less from lobe to lobe (the lift was 0.264-0.265: equal to 0.424" with the 1.6:1 rocker ratio).
I mention all this because the wear was/is very light for a vehicle that was not receiving regular oil changes (only every 6000 or more miles) and that was driven in very dirty environments (SoCal desert and Baja Mexico).
The kicker is that for 170,000 of those miles the air filter was (and still is) a K&N flat panel in the stock airbox. All the mild wear data suggests the K&N filtered (filters) extremely well (contrary to the numerous competitor sponsored studies that claim otherwise).
I have read many of the oil analysis tests and the static pressure drop tests, and performed actual airflow tests and oil analysis of my own oil, and my results were never as conclusive (or as negative) regarding a problem with a K&N filter.
The clean K&N will flow better than paper or oiled foam with less pressure drop, and with a carb you may need to rejet to make use of the power available through the extra airflow. On one of my other cars 327 the K&N element outflows the factory oil/foam enough to allow a slight step up on the AFB needles (worth ~0.15 seconds off the ET). This indicates the K&N can contribute to more power, if the engine allows fuel tuning to exploit the additonal airflow. The XJ MPFI adjusts itself for everything but WOT, so an injector change is needed to exploit any real power increase.
Does the K&N increase power in the XJ, without an injector change? Not really, maybe 1-2 hp, well below the power peak (better power under the curve, but with the same injector limited peak).
Does it impact emissions? My 88 easily passed CA emissions without a catalytic converter, with the K&N, when it had over 150,000 miles. I don't think it has an impact.
Oil or dust in the intake? I would make sure the CCV system is pulling air from the intake tube, and not pukeing unfiltered crankcase debris and oil into the intake downstream of the K&N. The crankcase can become a very nasty place if you allow unfiltered air to enter it (if the CCV system is defeated).
Read all you can, and post the links, but I will likely stick with the K&N.
The rod and mains were within standard bearing tolerance specifications, but out of round (wear was ~0.0005 more on the thrust side of the journals).
There was near zero ring ridge in the cylinders. The wear taper in the cylinders was ~0.001" (the top bore was greater this amount from the clean bottom of the cylinders). The factory hone cross-hatch was visible through the entire bore.
The lifter gallery was clean. The lifters were all worn ~0.005" on the tappet surface. The cam wear was 0.0005" or less from lobe to lobe (the lift was 0.264-0.265: equal to 0.424" with the 1.6:1 rocker ratio).
I mention all this because the wear was/is very light for a vehicle that was not receiving regular oil changes (only every 6000 or more miles) and that was driven in very dirty environments (SoCal desert and Baja Mexico).
The kicker is that for 170,000 of those miles the air filter was (and still is) a K&N flat panel in the stock airbox. All the mild wear data suggests the K&N filtered (filters) extremely well (contrary to the numerous competitor sponsored studies that claim otherwise).
I have read many of the oil analysis tests and the static pressure drop tests, and performed actual airflow tests and oil analysis of my own oil, and my results were never as conclusive (or as negative) regarding a problem with a K&N filter.
The clean K&N will flow better than paper or oiled foam with less pressure drop, and with a carb you may need to rejet to make use of the power available through the extra airflow. On one of my other cars 327 the K&N element outflows the factory oil/foam enough to allow a slight step up on the AFB needles (worth ~0.15 seconds off the ET). This indicates the K&N can contribute to more power, if the engine allows fuel tuning to exploit the additonal airflow. The XJ MPFI adjusts itself for everything but WOT, so an injector change is needed to exploit any real power increase.
Does the K&N increase power in the XJ, without an injector change? Not really, maybe 1-2 hp, well below the power peak (better power under the curve, but with the same injector limited peak).
Does it impact emissions? My 88 easily passed CA emissions without a catalytic converter, with the K&N, when it had over 150,000 miles. I don't think it has an impact.
Oil or dust in the intake? I would make sure the CCV system is pulling air from the intake tube, and not pukeing unfiltered crankcase debris and oil into the intake downstream of the K&N. The crankcase can become a very nasty place if you allow unfiltered air to enter it (if the CCV system is defeated).
Read all you can, and post the links, but I will likely stick with the K&N.
rockwerks
NAXJA Forum User
- Location
- Chito Beach Resort, WA
Read all you can, and post the links, but I will likely stick with the K&N.
Another man who did his own test, as I did years ago, the things work, I will always trust my K&N's
Another man who did his own test, as I did years ago, the things work, I will always trust my K&N's
ylojelo
NAXJA Forum User
- Location
- central VA
Hey 8mud, take a lok at this and let me know what you think (its the $11 hidden snorkle/cold air intake):
http://www.madxj.com/MADXJ/technical/technicalfiles/JJcustomSnorkle/CustomSnorkle.htm
here is a thread about it:
http://jeepsunlimited.com/forums/showthread.php?s=&threadid=439758&highlight=snorkle
I think its a great idea, haven't done it tho.
http://www.madxj.com/MADXJ/technical/technicalfiles/JJcustomSnorkle/CustomSnorkle.htm
here is a thread about it:
http://jeepsunlimited.com/forums/showthread.php?s=&threadid=439758&highlight=snorkle
I think its a great idea, haven't done it tho.
XJ Saga
NAXJA Forum User
- Location
- Ol'Virginy
http://performanceunlimited.com/illustrations/filtercompare.html
http://performanceunlimited.com/projectmpg/aircleaner.html
K&N's do work even on dead stock engines, the fipk will you give you more than a couple of hp.
http://performanceunlimited.com/projectmpg/aircleaner.html
K&N's do work even on dead stock engines, the fipk will you give you more than a couple of hp.
Dr. Dyno
NAXJA Forum User
- Location
- Al Ain, UAE
According to K&N's own dyno testing, the FIPK produces a 7.1rwhp gain on an otherwise stock 4.0 XJ:
The gain is even higher (11.8rwhp) on the 4.0 YJ since the YJ has a more restrictive intake than the XJ:
The gain is even higher (11.8rwhp) on the 4.0 YJ since the YJ has a more restrictive intake than the XJ:
Seriously, talk all you'd like. Bring you junk to the Drags and shut me up. Till then it's all talk...christ, it's not even web wheeling! It's worse!
Take it to the drags and run it flat out with a stock filter, then do the same with a K&N.
Know what, as soon as New England Dragway opens again we'll do it. I'll Go to NED and baseline the XJ with the paper filter. Then I'll toss in a K&N panel and run. Then I'll run with no box at all and no filter...
No Joke, let's make a meet and greet out of this for the New England Folks....
I read this, I saw this Blah blah ....we'll we've DONE this, and we'll do it again
We can get a stock XJ or two as well.
Take it to the drags and run it flat out with a stock filter, then do the same with a K&N.
Know what, as soon as New England Dragway opens again we'll do it. I'll Go to NED and baseline the XJ with the paper filter. Then I'll toss in a K&N panel and run. Then I'll run with no box at all and no filter...
No Joke, let's make a meet and greet out of this for the New England Folks....
I read this, I saw this Blah blah
....we'll we've DONE this, and we'll do it again We can get a stock XJ or two as well.
snake oil
No, the Tornado does not work, especially on an MPI system like the Cherokee uses. On a carbureted system the Tornado might just manage to give you an extra 1/4th horsepower or so due to better mixture of the fuel and air. On a Cherokee all it's going to do is restrict the intake flow.
Don't waste your money!
No, the Tornado does not work, especially on an MPI system like the Cherokee uses. On a carbureted system the Tornado might just manage to give you an extra 1/4th horsepower or so due to better mixture of the fuel and air. On a Cherokee all it's going to do is restrict the intake flow.
Don't waste your money!
XJ Saga
NAXJA Forum User
- Location
- Ol'Virginy
DARKFLY said:
Garbage. http://www.salemboysauto.com/tornado.htm
TOZOVR, I'm not calling your bluff. I'm posting links that are based on my personal experience with my fipk and on what, based on initial impressions of the product, I believe to be actual hp figures. Dino's jpg from K&N's own testing is more conclusive to me as well. I dont doubt your statements, I just hope you dont doubt mine either.
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