was wondering whats wrong with k&n air filters is it the turbo? and as money is a little tight for the holidays what is the best way to gut the cat? thanks all jared

94 2wh reg cab #6 plate auto

 

The K&N controversy, Hum. Well for my and many others money they stink. Heres why. Look closely at one, Its quite easy to see clear light thru the media even after oiled. What does that tell you. Theres no filtering protection. Granted as they say "HP gains, Higher flows more,bla,bla,bla" sure it does cause it has no restrictions cause theres no filtering. They state the dirtyer it gets the better it gets. True somewhat, it wont flow better but it will filter better. Now some of the holes are finally plugged with oily dirt and it will in fact filter better.These are my expiriances only. Im gonna get flamed on this one I know by those who love em. AFE is better OR?

 

BHAF with outerware prefilter, AFE PRogard 7, or Scotty 2.....these are by far your best choices. A K&N doesnt belong on these trucks, IMO.

 

I've bought a K&N for my last 4 cars and have been quite pleased with them, well all things except for one. When they are brand new their filtering is **** poor IMO. I didn't notice it so much until my MB, once I pulled the filter off and there was a fine dust inside the turbo. I like K&N but I don't think I'll buy another, I'm probably going to try AFE next time. BHAFs cost like $40 don't they? Granted it'd take a while for it to clog but a AFE is only a little over double that. Oh and one last comment, I'm anti filter cleaning. It'll look horrible but I won't clean it because K&Ns are at their best when dirty. Out of all the filters I've had I've only washed one, that was due to a exhaust leak about 2" away from it which had it layered all over one side of the filter.

 

For every story of a K&N passing dirt there are many stories of them not.
212k on my drop in K&N with no problems, it's only been serviced twice.
Most folks run into trouble by overservicing and not following K&N's service instructions to a T.

 

I could not possibly agree with you more Bill, I know a lot of people who think they should wash their air filter at every oil change or every other. You are the perfect example of what should be done, consider cleaning it every 100k miles or a little less. Not even paper filters are supposed to be serviced every other oil change, that is why they have the new vacuum gauges so people stop breaking the seal on the air box creating a possible entry point for dirt.

I can't say I've ever had problems with them, but I don't feel good about the amount of dirt they allow in when clean. I noticed it in my Talon and in my Mercedes. I never looked or noticed it in the other cars. Are they good filters? Yea. Are there better? Yes there is, next time....

 

Seriously Infidel, twice in 212k ? and no flow issues. Do you run a filter minder in a stock box? or BHAF? Thats pretty dang good

 

That sounds pretty good, remember he serviced it twice so it means it was clean 3 times which amounts to about 70k miles. I bet he could go a lot further than that before the filter minder would go into the red, unless it caught a lot of bugs and crap that get stuck in the mesh.

 

just put a BHAF on it... cheap, killer flow, excellent filtration, and best sound. you can't go wrong.

the best way to gut the cat is to remove it, hollow out the catalyst material w/ a crow bar or a piece of re-bar and a BFH, then run a piece of straight pipe through it so you don't mess up flow...

I hear ya on money being tight for the holidays. good luck on squeezing some more cheap power out of it!

 

If you decide to go that route;

BHAF
Fleetguard AH19037
NAPA 2790
WIX 42790
Donaldson B105006
Baldwin PA2820
Hastings AF1012

 

What is the expected life span out of a BHAF?

 

50K plus.

25K on mine, still fish belly white.
I also run an outerwears water resistant prefilter, wash it twice a year or so (every fuel filter change)


phox

 

food for thought,


1. What size pipe will slide inside of the cat?

2. With a pipe slid inside of the cat will it still act as a resonator to help reduce/eliminate exhaust drone?

3. How do the resonators in the 24v trucks flow, as they look just like our cats?

4. If their were some holes drilled in the pipe that we slid inside of our cat would we get the best of booth worlds? A drone reducer/muffler and good smooth air flow.



Just hopping to get some more ideas, which could help jaredbs and many others. I have gutted my cat, but have been pondering these things for a long time. I don't want to get rid of my cat because I have heard that it may be checked when going in and out of canada and want to avoid the hassle.


BTW I gutted my cat in the truck by using a large drill, making the holes, then vacumming it out and then putting everything back together.

 

My K&N, it's an FIPK II, works very well. 40,000 on it and going strong. I use the Filter Minder. Have used K&N for years on many vehicles.

As stated, I too believe over servicing, and specifically over oiling, is the problem for those that expirience problems. I have never had oil or residue in my intake tube or in my turbo inlet, as many report. I will leave it be until the filter minder says otherwise!

RJ

 

cut the cat ends so that you can slide a 4" pipe through it. if you drilled some holes in it, it would act as a resonator, but I wouldn't do it.

the 24v resonators are 3", but they neck down to ~2.75" at one point, and they don't look like a catalytic converter.

when you "gut" a cat, you remove ALL of the catalyst material... if you just drilled some holes in it, there's a good chance that it's going to crack and break up, and get lodged sideways in the pipe somewhere.

Forrest