One of my best friends is a diesel mechanic at a huge rig dealership in Ga. When he was in school up near Atlanta, learning to be a mechanic and getting certified, he had an instructor that was big on this kinda stuff. They were always testing stuff like throttle body spacers, synthetics vs. conventional oils, etc.
So anyway they dyno'd a 350 Chevy Truck, about a '98 I think, with a K&N drop in and it got about a 6-7 RWHP gain over stock paper according to their test. (Actually, the more I think about it, it may have been a K&N CAI they tested, I'll have to give him a call and clarify.)

As far as it letting more debris through, I don't know, I've heard it before. Read an article online, about how the the K&N and Amsoil filter flow about the same, but the Amsoil filters like 5x better.
Of course, there was a HUGE amsoil ad on the top of the web page. HMMMM...
Then, I've got a very popular off-road & truck magazine, and in an article from alate '06 issue, they rated the K&N #1 in airflow out of 8 tested, while not letting any larger particles through than any of the others tested. Of course, there were 3 separate K&N ads in the magazine. HMMMM...

So who the hell are you supposed to believe.

 

Sometimes it's hard to decide which to believe. In this case it's done for you....

 

Oh, I'm sorry P-man, my signature doesn't allow room for all my mods, so I have listed VERY few.
Let me upload this pic for you, buddy... I have the pretty shiny one, the one that REALLY echo's the EGR valve. I'll always have it in my truck, until Pappy gets the one that you have (he keeps saying he's gonna), and I switch my pretty, shiny, noisy tube for his ugly, dull, quiet one one night...

[IMG]local://upfiles/67238/CC66EAE9616C49158C3B3C3DB3A1D7AC.jpg[/IMG]

 

If you like drop-in style filters, AFE offers a synthetic one that uyou wash with soap and water instead if oiling.

 

I'm just waiting for things to settle down...Paying off the Harley and some bills.

Then it's K&N time.

Hopefully the Halloween Front Yard Security System will deter any K&N intake tube swapping. [sm=forgetit.gif]

 

You will get better MPG with the K&N.

 

Dont know if you will notice any HP gains with a big engine to start with but you may get some extra MPGs...my own experience with K&N filters is with my saturn SL1....right after dropping it in five years ago I could accelerate going up hill in 5th gear and the MPGs improved to an outstanding 48 MPG combined city/hwy...as for letting more debris thru, I recently did a compression test on my '96 SL1. Factory specs are 215 psi and my readings were 210 psi across the board.....letting debris thru? not likely

 

My question with the drop ins are this: How cana filterwith an overall less surface area allow more air pass? I don't care how well it's designed, because if by square inch it flows that much better then it can't filter as well.

 

Well, for me the proof is in the pudding. My eleven year old saturn with 300,000 km has compression that is 97 percent of original specs but lets say for instance that the rings are tight because of the synthetic oil I have always used...what about the valves? After five years of using aK&N filter if there was as much dust getting thru as people speculate then there would be evidence of wear on the valves as indicated by much lower compression test results...but there isnt. And the final convincer for me is that after eleven years including five years of K&N filtering, there isnt one iota of dust on the inside of the air cleaner right back to the throttle body. not a trace. So all you non-believers dig yur K& N filters out of the trash and put em back in...your going to be fine....

 

i dont know i have heard a lot of great things about true flow and i think that is what im gonna go with when the time comes try some research on them...