KNN Drop In Filter

Jerrygfd · 09-23-2004, 10:29 AM

I've read a little about this drop in filter and would like to hear from other Titan owners who bought one, mine is being shipped. There have been warranty issues, applying to much oil after cleaning, etc however, it seems in the long run this is a better filter replacement. Anyone seen any difference or any problems with this filter?

Smoke SE 4x4, UT Pack, BT, Off Road Pack, Power Cpt, Westin Plat Step Bars, Billet Grilles (Shipping from Socalmotorsports)

Hatchman · 09-23-2004, 10:56 AM

Dropped mine in, instal is easy, only took a minute. It came pre oiled, and I didn't apply any more to it. No problems so far, but usually they come pre oiled with just the right amount.

When oiling them after cleaning, just coat the filter enough to change the color from white to pink. If it comes dripping out at all, it's too much, and you'll probably have to re wash it to get some of the oil out.

I like it because it is suppossed to flow better than stock, get better horsepower, get better gas mileage, and can be cleaned and reused. Not sure about the better gas mileage or more horsepower, but I know I'll never have to buy another air filter for this truck.

the head · 09-23-2004, 11:22 AM

No problems with mine. I did not see a gain until after I put an exhaust on. It actually lost some mph in the 1/4 mile with the stock exhaust (barely). Even the gain was minimal after the Banks went in. Maybe 1-2hp, if that.

rawze · 09-23-2004, 12:31 PM

i love mine with the factory airbox mod

spoonman · 09-23-2004, 10:36 PM

we have one, no problems. One thing though is it does seem a little louder. Well maybe we didnt notice it before but i notice a "whoosh'ing" sound which might be because of more air. Not complaining though, sounds pretty cool

JS02 · 09-24-2004, 07:34 AM

I have had no problems with mine. I don't think there is much difference in performance. I like the idea that you don't have to buy new filters. I have used K&N filters on many vehicles and I have not had any problem with them. I also use them on some industrial diesels in my business. They have performed well there too.

Throttle · 09-27-2004, 12:36 PM

When I was trying to decide whether or not to use a K&N a couple of years ago I came across this site:

http://www.bobistheoilguy.com/airfilter/airtest3.htm

This guy really took a common sense approach to testing this. It seems that at least in this test they do flow more particulate matter. This doesn't answer the question of how harmful it is to your engine though. But it seems reasonable to me that less dirt in the cylinders is a good thing. If you're going to keep your truck for the long haul (pun intended), a high-flow filter may not be for you.

The other issue is performance. If you are trying to eek out an extra 10 or 20 hp at 6000 rpm, a high flow filter may be for you. If you mainly rely on mid range torque for you acceleration a K&N is not necessary. K&Ns literature gives cfm ratings for stock panel paper filters. If you do the math (I have) you'll find that flow restriction is only an issue at very high rpms.

http://www.knfilters.com/facts.htm

Note that these are average numbers. Now the cfm requirement of the Titan can be calculated by multiplying the displacement (341 cubic inches divided by 1728 for cubic feet) by the rpms divided by 2 (1 intake stroke out of 2 crank revolutions). This yields the cfm requirement for the Titan engine at that particular rpm.

For example: (341 / 1728) * (6000 / 2) = 592 cfm at 6000 rpm. That is not within the average clean paper panel filter (or K&N for that matter), but the Titan's panel filter is larger than the average unit. An average unit would be more like a mid size sedan like a Maxima. I originally did the calculations for a Maxima and found that it needed 318 cfm at 6000 rpm, which is within the average. Since I do not know the cfm rating on Titan filters, I cannot say for sure about them. But I would venture a guess that it is near 600 cfm. More info here would be interesting though.

I have performed back to back testing with Maximas and found that there may be a slight performance increase on the high end, but measuring the acceleration difference throughout the rev band yielded a different result. By leaving it in 3rd (it was a manual) and letting the engine pull from 2000 to 6000 rpm, there was no difference in the acceleration until maybe above 5500. And after repeated tests I was still unsure about that high end gain. I really enjoy high performance, but I will not sacrifice engine longevity to get it, especially if the power increase is only marginal, and at an rpm I am almost never at.

There are other flow issues that should be considered. Easing restriction does not always produce more power. It does in many cases, just not all. Since naturally aspirated (non-blown) engines fill the cylinders based on vacuum, pressure in the induction stream is essential. A buddy of mine had a 427 race Camaro when I was in school that ran stronger on a single 4 than two 4 barrels. Why? Pressure. Just like a nozzle increases the pressure of a water hose, a smaller intake can sometimes pressurize an induction system. In the short window an engine has to fill a cylinder this pressure is a big issue. So it is possible to actually reduce power if air flows too freely. In other words, there could be an offsetting decrease in power in the low end or mid range with a K&N filter. I doubt it though. Most of the airflow velocity and turbulence issues are handled by our very effective variable intake system.

For me, I guess I have decided K&N filters are not worth it. The extra dirt in the engine is what really gets me. K&N says its filters trap more particles once they get a little dirty (they don't mention what happens to flow), but that's just another area where I'm skeptical. If the power increase was across the band and very fat (and its not), I would still be leery of this dirt issue. I am planning on keeping my Armada as long as it will run. If I still own it 10 years from now with let's say 300k on the odo and it uses little or no oil, I will be a happy dude. However, for folks that plan on trading before 100k, it is probably a non-issue.

GETSOMZ28 · 09-27-2004, 02:29 PM

Quote:

Originally Posted by Throttle

For me, I guess I have decided K&N filters are not worth it. The extra dirt in the engine is what really gets me. K&N says its filters trap more particles once they get a little dirty (they don't mention what happens to flow), but that's just another area where I'm skeptical. If the power increase was across the band and very fat (and its not), I would still be leery of this dirt issue. I am planning on keeping my Armada as long as it will run. If I still own it 10 years from now with let's say 300k on the odo and it uses little or no oil, I will be a happy dude. However, for folks that plan on trading before 100k, it is probably a non-issue.

Good informative post. I am with you that it is not worth the etra dirt it allows into the engine. As a matter of fact, I have gone back to a paper fram filter on my modded LS1 after realizing 0 hp gains from a Holley Powershot filter (same as K&N, but seals better).

Throttle · 09-27-2004, 08:00 PM

Quote:

Originally Posted by GETSOMZ28

Good informative post. I am with you that it is not worth the etra dirt it allows into the engine. As a matter of fact, I have gone back to a paper fram filter on my modded LS1 after realizing 0 hp gains from a Holley Powershot filter (same as K&N, but seals better).

Scott,

Very, very interesting. Since your Z has virtually the same displacement and probably the same size panel filter as a Titan that is an excellent piece of corroborating information. I too ran the high flow filter (K&N in my case) for a month or so before switching back to the stock paper unit. BTW, what mods have you done to your Z? I used to run a 454 Chevelle with nitrous back in the day, and I'm a big Chevy fan when it comes to high performance street cars. Would love to hear what you've done to it.

Chris

GETSOMZ28 · 09-28-2004, 08:19 AM

Truck 41, It has been the real world track/dyno results that I (as well as alot of the LS1 community in general) havent seen any measurable performance gain using a K&N or similar cotton air filter over a cheap paper filter. I think the gains people see when they purchase the FIPK is from the design of the straight flowing tubes (no more stock silencers) and not due to the filter itself that you will get any appreciable gains.

Some of those finest engines you are talking about are only good for a couple races, not 100K miles. I challenge you to do a back to back track run with the K&N and stock filter to see if there is any difference. I have and found none.

Throttle, my Z is modded with a 3000 stall, 3.42 gears, longtubes, cam, and a few misc other items. It is good for running 12's at 8000ft DA.

GETSOMZ28 · 09-28-2004, 09:07 AM

One other thing about re-useable filters. GM has gone so far as to send out a letter to all their dealerships to deny warranty work on cars that have these installed. They have been known to wreak havok on MAF sensors and such. Even on this forum, some folks have had problems with theirs. Funy thing is these dealers sell the K&N filters in their parts dept...

Now if someone would make a paper filter that would fit on the end of the tube that comes in the K&N kit would be the best of both worlds.

Throttle · 09-28-2004, 09:24 AM

GETSOMZ28,

Interesting post. I have also heard of the MAF issue but was not aware of the service bulliten. Makes sense though. After I became dissillusioned with reusable high flow filters I went out and found a round paper filter at Advance. It was for Chevy pickups and Tahoes. This thing is big too. The K&N literature I posted shows a dramatic flow difference between round and flat panel filters. I believe this is due to more surface area for flow that can be achieved in a smaller space. So I went out and found the biggest round paper one I could find and attached it to the CAI I had for my Maxima. I didn't do enough testing to say for sure that it worked. But in principle, it should improve the flow, assuming K&Ns stats are legit. I actually took it back off because of the noise. This is a quiet car and I kind of like it that way. Plus, a V6, or I4 for that matter, just don't have that good sounding growl from the cowl you get with a V8. My opionion I guess.

Throttle

Titan4x4Aggie · 09-28-2004, 10:35 AM

any pictures of this round filter?

i wonder if you could fit it into teh stock air box with a few more mods in addition to trimming the extra plastic off.

GETSOMZ28 · 09-28-2004, 10:43 AM

yeah, my '96 Ranger with the 4.0L had a paper cone filter also.

GETSOMZ28 · 09-28-2004, 10:44 AM

here is the bulletin from GM about reuseable filters:

WARNING: All K&N And Other Rechargeable Air Filter users
The following is a memo from GM stating the use of rechargeable air filters may cause transmission shift problems, engine driveability problems & SES Light On problems (throwing codes). It also states these problems will NOT be covered under warranty. Yes, in part of the memo, it states "excessively oiled" filters. But for the most part, it reads any use of this type of filter & these issues won't be covered. I just figured some of you might want to know so you can throw a paper filter in if you take your car in for a problem.

SERVICE - ALL BUICK, CADILLAC, CHEVROLET, GMC TRUCK, ISUZU, OLDSMOBILE, PONTIAC AND HUMMER DEALERS

Subject: A/T Shift, Engine Driveability Concerns or SES Light On as a Result of the Installation of an Aftermarket Reusable, Excessively Oiled Air Filter -- 2004 and Prior Cars and Lt Duty Trucks and 2003-2004 HUMMER H2
Message #: VSS20040056

Corporate Bulletin Number 04-07-30-013 will be available in SI on March 18, 2004.

Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES)
Light On as a Result of the Installation of an Aftermarket Reusable, Excessively Oiled Air Filter

Models: 2004 and All Prior Cars and Light Duty Trucks
2003-2004 HUMMER H2

DO THIS
First, Inspect the vehicle for a reusable aftermarket excessively oiled air filter

DON'T DO THIS
DO NOT repair under warranty if concerns result from the use of a reusable aftermarket oiled air filter.

The installation of an aftermarket reusable, oiled air filter may result in:

1. Service Engine Soon (SES) Light On

2. Transmission shift concerns, slipping and damaged clutch(es) or band(s)

3. Engine driveability concerns, poor acceleration from a stop, limited engine RPM range

The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur.

When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively oiled air filter. The MAF, GPS reading should be compared to a like vehicle with a OEM air box and filter under the same driving conditions to verify the concern.

Transmission or engine driveability concerns that are the result of the installation of an aftermarket reusable, excessively oiled air filter are not considered to be warrantable repair items