Napa 6637 vs. OEM Filter

07strokerftw · Sep 17, 2011

I'm posting on my brother's account (creating new account soon) and I have a 2001 F250, just curious as to what the better option would be for optimum filtration AND air flow. Previous owner had a K&N installed in the factory location, and I just pulled it out and washed it today and got it nice and clean, but I don't trust the K&N's. Checked the intake tube and it looked clean for the most part, but I was just worried since the K&N had been on there that it may not have been filtering as well as it should. Let me hear it

Talyn · Sep 17, 2011

There are good K&N systems out there.
but as for a K&N stock replacement? They are junk.

I had great luck with my K&N on gas motors. I just dont think I'd trust it on a diesel.

Arisley · Sep 18, 2011

Nothing wrong with a 6637. Especially until you decide an something else.

07strokerftw · Sep 18, 2011

I'll probably keep the 6637 for a while, the way I've understood it you remove the factory intake box and the filter attached directly to the intake tube? Is this correct?

Viking · Sep 18, 2011

My 6637 AFE "BIG" boost didnt fit in the stock location. I had to trim off the air box "frame" that is attached to the battery box.

I have an 03 with the 7.3

07strokerftw · Sep 18, 2011

I already plan on removing the box if its necessary, which if I understand correctly is what has to be done

Arisley · Sep 19, 2011

Correct. Just remove the factory airbox completely. On some trucks you have to do some trimming. Or get an early 99 battery tray.

Big Bore · Sep 19, 2011

Arisley said:
Nothing wrong with a 6637. Especially until you decide an something else.

Just curious, and I'm not trying to stir, what else would you use?

Talyn · Sep 19, 2011

they make a few cold air kits which replace the battery try and stock air box.

Some argue that pulling from the engine bay pulls hot air.
but I don't think they factored in that our trucks are huge air scoops and the air in there is always outside temp or colder.

I've watched my OAT on my scangauge, it's really accurate.

lincolnlocker · Sep 19, 2011

Talyn said:
they make a few cold air kits which replace the battery try and stock air box.

Some argue that pulling from the engine bay pulls hot air.
but I don't think they factored in that our trucks are huge air scoops and the air in there is always outside temp or colder.

I've watched my OAT on my scangauge, it's really accurate.

at idle not moving it pulls hot air. but once you get moving past 30mph the under hood air temps stay close to ambient air temps...

OP. lots and lots of people run the 6637. i would still have it if i didn't get amsoil dryflows for cost... 6637 has the best filtration you can get at a higher flow rate.

Big Bore · Sep 19, 2011

After running oiled filters on at least a dozen vehicles including AFE intake and Pro Gaurd7 on my 96 F350, I love the Tymar/6637. No washing or oiling. No pinholes (trust me, if you run it dusty, it has pinholes. Take it in a dark room and stick a flashlite inside, the sealing will look like the stars at night.) and change intervals are much longer. I dont think the oiled filters hold up to the velocity of air being sucked in by our high boost diesels.

Plus, the 6637 flows more air.

I will never ever run another oiled filter on my trucks.

Tonka350 · Sep 19, 2011

I've been running my 6637 kit from riffraff for almost 2 years now and I love it. between my wicked wheel, intercooler pipe foil removed and the filter my turbo is loud as he!!. it's really a great filter, but your best bet while you're doing it is make a whole new intake pipe from a piece of 4" exhaust pipe and do the CCV delete at the same time. it really paid off on mine.

Chad

Arisley · Sep 19, 2011

Big Bore said:
Just curious, and I'm not trying to stir, what else would you use?

Personally, I am running a 6637 and have been for about 80K. Some people want the nice pretty enclosed filter that costs a lot of money. For me, the 6637 is what I use.

OBSWIZ · Sep 19, 2011

IMO, get the orginal a Tymar intake kit with the correct Donaldson filter..we have them in stock.

07strokerftw · Sep 19, 2011

Great info guys.

PStroked444 · Sep 20, 2011

I looked at my fathers 6637. I helped him install it about 3 years ago. Its still on there LOL Today it is black and dirty. I told him I would get him a new one. He replied "Im still getting 20mpg why waist the money". Just a funny thought.

07strokerftw · Sep 21, 2011

What did you do to install it?

PStroked444 · Sep 21, 2011

I used 3" of 4" ehaust pipe as a coupler for the 6637. I first painted it black just because. Then I slid one end into the stock intake. The rest slids right in to the filter. I guess I should say I removed the atock air box befor placing the filter in the truck.

Its a little tight but, a small amount of grease on it helps it slide in.

On a side note I used some dryer exhaust tubing to help syphen some cool air directly to the filter. Dont think it really helps but....its not hurting anything.:shrug: