I ran a stock replacement AFE for a while. I DID get residual oil initially. Changed to BHAF. When the BHAF got bad, I put the AFE back on and didn't see the oil again. I have not seen a K&N myself, but seems I read they are slightly smaller than the AFE, so I would assume the filter oil gets sucked in at a greater rate. I must've just injested the excess initially with the AFE. My limited experienced opinion, is that the residual oil being found on the turbo blades is trapping the extremely fine dirt that you wouldn't normally be aware of. I did not and would not spray anything on the blades to clean them, they cleaned themselves during the time I ran the BHAF. My intentions are to eventually make a nice air box for a BHAF for the most flow after future mods. It's just the AFE is good enuff for what I have now (as I never saw a differance running the two), and my BHAF kept getting trashed while unprotected. I have not seen anything where anybody actually dimanteled any of the filters to compare mmedia and construction, hopefully it won't be too long and mine will be available for testing if anybody wants to take it on.

 

This is off the subject.

I keep reading about air flow, which filter is best, and lower EGT's.

If your truck produces 32 lbs of boost with a stock filter or 32 lbs of boost with a K&N or 32 lbs of boost with a BHAF or 32 lbs of boost with any filter how can it change air flow or lower EGT's? 32 lbs of boost is 32 lbs of boost, the engine is engesting all the engine can engest at 32 lbs unless you increase boost. Now if the different filters allow different boost numbers then that would be the real comparision as to why you should use any filter other than a stock filter. On a stock engine that limits boost through the ECM and MAP sensor you are not doing anything except maybe a minutly small amount of faster spool up of the turbo and that is hard to prove by seat of the pants testing and I have not read any testing done on spool up speed.

 

Way I see it is if the filter minder isn't pulling down the engine is getting all the air it can use. Think a lot of people use other than stock filters when they don't really need to.
Another thing I'm highly skeptical about is when folks say such and such filter lowered their egts 150°.
150° compared to what? Did their egts really need to come down that much?
I've found it almost impossible to duplicate conditions were a person can honestly say their egts have dropped due to a particular mod except on a dyno.

 

I would think the pressure would not change, but the quantity (CFM) would improve/increase.

 

All the cussing about K&N Filters here, I want to make sure I understand. Most of what I am reading here talks about the replacement K & N filters for the stock air box, I have the Air Canon on mine, is that also include in this conversation?

 

AT 28 PSI currently, my point was that I don't feel I'm benefitting from what the BHAF is capable of. There is some difference going from stock to a swiss cheesed box and AFE, or open BHAF. I don't have my pump turned full blast yet because of stock injectors, but when I get POD's, crank the pump and modify the turbo, I assume I'll get more use out of the BHAF than I have been. I am shying away from the oil element filters, because I will be pulling more air and don't want to injest the oil everytime the filter gets reconditioned. The larger, cone shaped filters would probably offer the least resistance to sucking in the oil, which is probably why the K&N got noticed so quickly, being the smallest offered. Looking at how thin the element is compared to the element on Karen's Ford gasser K&N, I'm sure there's little, if any difference in construction technique. I also use permatex on the seal BTW.

 

rare1, do you still have that k-n? i'll give you 10 bucks for it. i don't think eople know how to clean and oil it properly, and that is why it doesn't work as good as it's supposed to. if you still got it, pm me and i will buy it from you if it will fit my truck. 94 model

 

banks twinram, donno if it will fit, but I'll keep it for further comparisons.

Everyone, I took the K&N out of the box, greased it PER INSTRUCTIONS and ran it for 2000 miles, resulting in 41 PPM silicon. I did not clean it or oil it or peek at it to see if it was dirty. IT WAS NEW AND PROPERLY INSTALLED. The paper NAPA I took out had 15-20,000 miles on it, was dirty but not clogged, had no holes in it, and yielded 4 PPM silicon on the last oil change.

If some get low PPM and others get high PPM silicon (with a NEW K&N, and low PPM with a paper filter) a logical conclusion is that K&N quality control is poor. Yes, a dirty air filter traps more dirt than a clean one, but don't ask my engine to be a dirt trap while the filter is loading up. A paper filter starts with clean air and still provides enough intake during the life of the filter, on my engine.

At some later time I'll do an experiment by swapping filters again with more oil analysis, maybe run the K&N (without cleaning and oiling it) on alternate oil changes for a while to see if the PPM silicon jumps up and down.

 

Not saying you didnt do it right or you dont know how to do it but did you make sure the K&N you bought wasnt damaged? Holes, tears, bad construction, ect.? Maybe your air box didnt seal right, being different than the Napa? Just questions.

 

I don't claim to be an air filter engineer but my stock filter had 5000 miles on it when I replaced it with the K&N. 90000 miles later my K&N filter is cleaner than my stock filter was after 5000 so the only conclusion I can come to is it's not stopping the dirt. After reading Rare1's post I went to Napa and got a Napa gold filter I don't know if it's any better but I feel better about it. I've been putting this off thinking the K&N is really filtering better than I think. I haven't ran it hard to see about boost or EGT's. I'm running 39 to 40 psi so if it cuts it down that's fine to I'm just super heating the air after 36psi any way.

 

I have run a K&N FIPK II, with the larger "cone" unit (see gallery), for last 50,000 miles. Boost levels up to 51 psi. High grade synthetic oil run for 10,000 miles between oil & Fleetguard filter change. Oil analysis has showed 3-5 ppm Silicon every change, and my air inlet tube has been spotless. The only exception was a very busy time, with lots of dirt roads, when I went 13,000 miles between changes...with a silicon reading of 15 ppm.

I believe talking about silicon levels, without including the variable of type driving and change intervals...is misleading. Also, the 15 ppm is no biggie for the amount of back roads I drive...was not even "flaged" as "corrective action recommended". Those who argue over 3 ppm vs 10 ppm are, IMHO, picking at nits!

I suspect many overservice their K&N's...others appear to have gotten poor results from original K&N's which may denote poor quality control at the factory?? Don't know about that, all I can say is......
My K&N has served me well!

RJ

 

The main reason I like the BHAF over the stock filter is getting rid of the gasket. That is just a problem waiting to Happen if you are pulling high flow through the stock box. It just wasn't designed for that kind of flow, no matter how many holes you put in the box. It still has to pass through the flat element area.

Having a clamped connection to the filter makes me feel better about the seal to the outside world.

J-eh