Chrome intake with K&N

Well..... Even the K+N has been shown by folks on this group that it passes dust through.

I like to have my engines running really well and I stick with stock paper filters.

Being able to breath more air in doesn't really help a 4.0 unless there is some place for it to go so if you put on some headers and a 'cat back' and maybe a cam, then it might be worth the extra dust and wear, maybe....

Just my $0.02,

Mike

I've always run a K&N intake on my 91 YJ -- AZ, NM, NV, UT and the mid-atlantic states. I've got 255K on my Wrangler and it's still going strong. Therefore, I don't much believe that the K&Ns are any less capable than the OEM paper filters. Proofs in the pudding.

There have been several occasions where I have ended up with an oil soaked air filter that wasn't working or passing air any more and I have just taken the sucker out to continue on. Running with no air filter and then putting one in has made no noticeable difference in the performance of my engine.

I have done this with 'both' my 4.2 and 4.0 engines due to the PCV or CCV systems having the odd fit.

Therefore I sure wouldn't bother using a 'performance' air filter that even admits on it's website it lets more dirt to pass than an OEM filter. Makes no sense to me.

Mike

"L.W.(Bill) Hughes III" wrote:

I have considered 'streamlining' the factory intake while retaining the paper filter.

It seems reasonable that the intake resonator and the corrugated piping introduces disturbances in the airflow that robs performance.

Of course, I don't know how much, if any, effect this would have on the engine but as K & N (and others) claim that the 'Intake Systems" are superior to just their drop in filters (into the factory airbox) it would be reasonable that the improvement is actually due to the smoother airflow into the throttle body.

Has anyone tried this?

Most of their effect is supposed to be due to picking up cooler air from their physical location. If that air intake happens to be where there is also a local boost in air pressure, you get kind of a poor man's supercharging effect. Is why some of the old muscle cars had actually functional hood scoops and some of the smarter ones picked up the higher pressure air often found at the base of the windshield. For some cruising performance boost maybe the OP could attach a few air pressure sensors to a laptop and move them around until a location with a pound or so off local pressure is located. Add temperature sensors and choose the lowest temperature and highest pressure available.

The shape of the intake channel isn't as important as it might appear, at higher speeds the airflow takes place in the main channel using a boundary layer that forms along the irregularities. Most of those creases and such are to stiffen to avoid intake boom while avoiding weight. Too smooth is actually worse than some roughness. The air will try to stick to a smooth wall more. Most hotrod manifolds these days use microsurfacing rather than the old smooth polishing that some hot rodders thought was a good idea.

billy ray proclaimed:

You have to 'really' watch out for ram air scoops in Jeeps! Some YJ's and also TJ's I think have a ram air scoop just below the headlight. If you cross water with this hooked up, as soon as the water tops the bumper, gulp and your engine is hydrolocked.

I know folks like 'seppster' from this group has disconnected his and routed it with ABS pipe up higher and pointing back I think too.

Others didn't know they had it and oops...

Mike

On the WJ it is alongside the driver's headlight at a height of 36" on a stock suspension.

When going off-road you can pull this off and rotate it upward so it is now at the height of the top of the airbox.or attach an air hose and relocate the intake to the rear of the engine compartment.

At a local off-road rally last month a local Jeeper couple tried to see how fast they could cross a water hazard and hydro-locked their motor.

Almost all of these systems are set up so they draw superheated engine compartment air from the nearby exhaust manifolds

When I put the K&N in my Cobra, I immediately noticed a difference in the way the car 'breathed'. It was as if I had taken a pillow off of it's face.

I won't put one on my Jeep though. I hated the maintenence BS with the K&N, it's a real mess cleaning them and the cleaning kit is around $30

I'd rather just change the paper filter than mess with the K&N

Kate

Turbo City's Rock-It! air tube gets it from right on top of the valve cover. In city traffic it can get hot up there, but it must be cool enough going down the highway. I am getting 25 mpg in my four cylinder 1995 Wrangler. One of the things we learned in science and engineering courses was not to put too much weight in unverified theoretical predictions.

Earle

FWIW I'm using the Jeep/MOPAR air intake on my '04 TJ six and it is positioned in the right front of the engine compartment as high as the original box with snorkel. The kit also includes an air dam/shield between the intake and engine. It was dealer installed and at least my dealer says the warranty is unaffected. They service the filter when I get my scheduled service. My gas mileage ranges from 19+ to 23+ with most tanks getting 20 to 21. It varies with a/c use and type of road used.

Sounds like your system is still sucking in heated (engine compartment) air.

There are a very small number of these K & N type systems that duct in outside air into the 'shielded area' but probably 99% of the setups I have seen the filter is still ingesting engine compartment air.

The factory airbox uses a cold air intake.

I was not planning to change away from the paper filter, I was thinking about smoothing out the disruptions in the intake air pathway.

Imagine coming off the throttle body with a 90 degree fitting (like the K & N) and then running smooth walled tubing to the factory airbox which would hold a paper filter, just like now.

The factory airbox has a cold air intake which is located along the driver side headlight. On a stock height WJ it is 36 inches off the ground

Many years ago when the so called oil bath high air flow filters came out many of us who ride motorcycles switched. A very bad idea, as it is today too much stuff gets through it does not burn and guess what, it scores the cylinder walls causing the bike to be rebuilt way before it is time to. Still today K&N and others sell them and still people buy them. The same holds true for autos many manufacturers do not recommend the use of the oil bath high flow filters. Penny wise and pound foolish and they are no bargain. Coasty

The intake on the box that was taken off was in virtually the same location in the engine compartment as the intake I had put on. How could the original get air from somewhere that the new intake couldn't? There was no "outside" intake on the original. And the original intake had no air dam/shield between it and the engine. I'm not making any radical claims for the setup although I am very happy with my mileage and overall performance.