NAPA BHAF vs K&N

[stownsend]

Thought you'd heard enough about air filters... I've got another one for you. About a year ago, I installed the NAPA BHAF... the suckers about as big around as a basketball. I thought I would give it a try to lower EGT and increase power. Besides, it was fun to show to my Power Stroke lovin friends.



This year, I put back the stock box with a K&N filter. I was surprised. With the K&N, at 70 MPH on level road, the EGT is 25 degrees lower. On a hill pulling a 20' boat, the EGT is 100 degrees lower! I also noticed that the overdrive kicks off later with the K&N than with the NAPA. But the down side; more air = more fuel. The fuel mileage is worse with the K&N.



A couple of things may attribute. What do you think is more significant?



1. The NAPA is exposed to hotter, less dense air. (However, I drilled 4 or 5 1-inch holes in the bottom of the stock box for the K&N, so it is also getting some hot air from the engine compartment. )

2. The K&N lets more air through than the NAPA.



Opinions??

 

[bmoeller]

But the down side; more air = more fuel. The fuel mileage is worse with the K&N.

Did you change how you drive at all? You will only need more fuel IF you are using the fuel (power). I never saw a difference in mileage between the 2.



I had a slight drop in EGTs running the BHAF, vs. the K&N. Couldn't get the air box to seal properly, even with gobs of grease on the sealing gasket. Won't ever go back to the K&N, even if it was given to me.

 

[Supermod56]

See if you can either buy or build a cold-air box for the BHAF. Like the AFE has, might help!

Tom