Running a Pre-filter. Choking off engine?

[ryan2022]

Hi guys,

I'm thinking about running a K&N foam prefilter on my Jeep.

I'm running the stock paper filter in the factory air box, but I'm thinking about running this extra filter over the inlet of the airbox.

Some of the areas I run trails gets REALLY dusty.

Would this hurt the engine at all? I'm assuming it'll add a little more resitriction to the paper filter.

Any input?

Thanks

 

[OAS]

Are you getting any dust through the stock filter?
Look up into the intake tube to see.

A prefilter will most likely restrict flow and lose a bit of power.
I know its not the same situation, but i tried that with one of my dirtbikes a few years ago.
Cut a small section of the white poly prefilter that the used to use on the old 7.3 powerstrroke deisels.
(about 1/2 inch thick)
put it over the airhorn under the seat, and the bike barely ran!
It was a lose poly foam material and you could see through it, but it was just too restrictive for the 500cc motor.
Im sure it wouldnt be so bad with the Jeep, but it would still lose a bit of power im sure.

 

[JakeR22]

I've thought of that before too.

It would make your paper filter last much longer.

I would think the only possibility of restricing flow would be at wide open throttle, towards redline, where your engine needs the most air. So if you don't drive much like that, I'd think it'd be fine.

 

[mechjames]

I got my prefilter from Outerwears racing. Its not foam, it's polyester mesh with uniform micron openings, treated with an optional hydrophobic water-repellent process. (yes I copied and pasted)

It doesn't seem to make any difference at WOT unless its dirty from using my Explorer Offroad. But they are cleanable in a soapy water solution.

I do have a S&B open filter element though.

 

[ryan2022]

Thanks guys,

I actually just ordered it. The filter is for an ATV, and is roughyl 3.375" in diameter. Its supposed to be oiled, but I might just run it dry, and keep it clean.

I figure this will be a good comprimise. I may just run it while offroading though.

I may move to 1 year/ 9K oil changes, and want to keep the oil as clean as possible.

 

[Hitzy]

Pre filter is normally used to catch the bigger stuff, should not restrict airflow unless it gets really clogged up.

 

[widman]

I don't see much reason to guess at filter changing when $20 and 5 minutes labor can put a restriction monitor on the intake. It will show you when to change, or in this case if the prefilter is too restrictive.

 

[Loobed]

Originally Posted By: JakeR22
I've thought of that before too.

It would make your paper filter last much longer.

I would think the only possibility of restricing flow would be at wide open throttle, towards redline, where your engine needs the most air. So if you don't drive much like that, I'd think it'd be fine.



I had some extra foam material from my off road motorcycle that I installed into my airbox because I was getting rocks, leaves and sticks inside the airbox, and I wanted extra protection. I did not get any flow restrictions.

 

[virtual]

I would just had a snorkel if i was you, instead of the ram air,run a prefilter on top of it.Now all you have to do is extend your breather,and you can have some fun in mud and water .