Does anyone know if KN makes an air filter for my 04 Cummins? My dealer told me KN filters allow more abrasives through than conventional filters, but I think he is only trying to protect the parts department at the dealership. Also would an aftermarket filter void the warranty?

 

For a change I actually agree with the dealer

The K&N's have a bad rep for not sealing well in these trucks, there are MUCH better alternatives out there.

 

You'll get a lot of opinions about which air filter to use, but most agree that for our trucks, K&N isn't the best option.

I've had both Airaid and AFE Pro-Guard 7 in my truck. The Airaid isn't bad at all, and never let anything through that I could see or feel when I drove down normal roads. But the more I started running dirt roads, I would find a little dirt got through, not a lot, but some. Switched to the Pro-Guard 7, and so far nothing has gotten through, and my air filter minder still hasn't budged (unlike with the stock filter). Also you'll hear of folks with foam filters and such as well. Like I said, everyone has an opinion, but you'll find AFE's to be pretty popular among this group (who, as far as forums go, tend to be pretty on the ball).

 

I have an Amsoil foam replacement filter that appears to be working very well, in addition to dropping my EGT's nearly 300 degrees.

 

300 degrees from an oiled foam drop in? Must be that Amsoil miracle in action again...

 

I had to force myself not to make this same comment. But I was going to add; "No need for a twins now"

 

i also run the drop in amsoil filter, works better then factory junk!!!
the KN's work good, but they work good only dirty, as they let too much fine dirt pass through.
i wouldn't run one , but any of the 2 stage foam ,oiled filters and kits will work great.

 

I run the TrueFlow oiled foam air filter and like it very much. I drive a lot on dirt roads and when you look down the tube it is clean as a can be. If you are off road a lot I highly recommend a oiled foam filter.

 

AFE makes a drop in filter nearly identical to a K&N. IMO its still too small too allow adequate airflow. I took out my stock air box, bought an AFE ProGuard 7 Conical replacement filter(90007) and mounted it to the stock rubber with a PVC connector and clamps. I took the Air sensor and drilled a 5/8 inch hole in the rubber and screwed it in. Made a little bracket that attaches from the heavy rubber of the top of the filter to a bolt on the radiator mounting for supprt. Also bought an AFE prefilter and the setup looks and works great all for $125.00 bucks.

 

I prefer the True Flow oiled open cell foam for dirt retention as well as air flow.
The True Flow is a drop in replacement made by Uni Foam Filters for True Flow. Scotty now uses a pod type (round cylinder style) Uni foam filter with his systems. The True Flow drop in part number for the 2003-2005's 5.9 CTD's is 30200. It has a formed silicon rim around the filter kind of like the OEM paper.

I have an Amsoil TS189. The blue surround separated from the foam filter media. It's going back to them. I'm sure it let plent of dirt in my '04 since it wasn't sealed due to the delamination problem.

As far as the oiled cotton gauze K&N style, the AFE Pro Guard seems to offer the best protection for that type of filter media based on several UOA's I've seen over at bobstheoilguy.com. Silicon numbers have been quite respectable.

 

I'm running the Airaid kit now. Seems so far to be doing good. I agree with the K&N. I used to run it on my quad and once in real dusty conditions most of the fine grit went right through. I don't mind them so much for dusty conditions anymore. I figured I'd try Airaid and see how that treats me. Once you buy a intake kit, or even not, you can try different air filters and see which one you like best.

 

I like the AFE progaurd 7 drop in. Lots of guys don't like the drop in set-up, but mine has worked great.

 

I might try one of those True Flow air filters.

MikeyB

 

Except the AFE has more layers and is pretty universally been found to filter better.
I suppose the "too small to allow adequate airflow" could be true, but I submit it depends on what you are doing to the truck.

My filter-minder has not budged since it went it, which is way more than I can say for the stock filter (that was well over 50% down stemming from just one trip to the floor....). My personal truck is pretty much stock at this time, and the way I figure it if I'm drawing a big enough vacuum to pull that minder down, I've got plenty of flow.

Now, with mods and more boost, etc., that could very well change.

 

FWIW, I dynoed pre-twins install with the B1, stock drilled airbox and AirAid MIT (in the classifieds), and a stock filter. 467hp and 1187tq at 44 lbs of boost. Doesen't sound terribly restrictive to me or I wouldn't have seen 44+ lbs with a stock filter. Just for reference, not trying to be argumentative.


Richard