K&N filter with Evolution
 

New to the site and I have ordered an evolution a few months ago and love it. I am in need of a new air filter and am thinking of going with the K&N drop in filter. I've heard of people running lean with the CAI and custom tunes took care of that. My question is do I need custom tunes if I am only running the drop in filter? Only other modification I have is flowmaster SI/DO exhaust and my truch is a 2004 f150. I will probably upgrade to custom tunes sometime in the future but right now I don't have the need to.
Thanks.

I'm pretty sure a drop in filter will not affect the air flow enough to cause a lean condition. I believe a lean condition only arises by adding a CAI system of whatever brand you decide on.

Ehh hard to say :notallthere:,the 04-05 can be strange beasts when it comes to messing with the air intake.The gotts mod also increases air flow but im sure not as much as the K&N will. The K&N to me will add much more air flow than stock and the Gotts mod. With more air flow than the Gotts i wonder if a custom tune will need to be built. This will be best answered by bill. Very unique question!

Pretty sure a drop in filter makes little or no difference in causing a lean condition as it is well after the air flow sensor and there is no difference in the routing of the air. The CAI type dramatically changes the way the air enters the motor with the filter being first in line. However, been wrong before :)

I got the K&N filter and noticed a small difference after installing it. Also noticed a little more power after doing the Gotts mod. Those two by themselvs do not need a custom tune calibration because it does not effect the flow of air over the MAF sensor. I was just chatting with Bill yesterday about it, and as long as the air goes through the same stock tube that holds the sensor, the computer will still know how much air is coming through and keep the A/F ratio up to spec.

I had the K&N drop in before getting the FIPK and noticed the same as you.....plus a tick louder when ya floor it.

OneTom - you're right as usual! The K&N will not need a new tune. It has no effect on the MAF environment. Longshot, you're dead on too.

That's it - I'm going to take a year off! :howdy:

As an aside though, I HAVE heard that bad things can happen if the oiling of the K&N is not done properly. This seems a pretty rare thing, however.

- Jack

thanks for all the help here. Now I feel more confident getting this K&N filter but will still probably upgrade to custom tunes in a year or so. Great website with lots of good information!