Dear Editor Cappa,

Re "Air Filter Blowout - which brand filters dirt best and makes the most power."

Did the last page get left off? Very useful introduction, and the test results were useful as bald numbers, but what's the conclusion? In sum, which is the best way to go? Which brand filters dirt best? And what about power, as per the subhead? Saying you couldn't work it out is a bit of a copout, given that's it's part of the subhead. Did the less effective cumulative brand mean it was less restrictive, then (theoretically) more able to play a part in increasing power? Some discussion would be nice. Does the better dirt-holding ability in the short term outweigh the longer term cumulative, considering you can clean it once you stop, but not when you're moving?

And, maybe you were talking about volume, but I thought there were 28gm to an ounce, making 7 grams about one quarter of an ounce, not 4 ounces.

Lastly, and on another topic (guess this is my b**tch night), while the JK seems to be pretty good, glossing over an increase in 750 rpm on the highway - 750rpm! seems a bit much. For a stock TJ that's nearly a 40% increase at 70mph. And while you sneered all over the Commander for being an SUV as it was probably mostly for sale as 2WD, you've ignored the ultimate in sacrilege - the real jeep, now the JK, being sold in 2WD. The ultimate brand cut.

Other than that, good mag as usual.

I suppose it is a little difficult to figure out. However, if you analyze the numbers it's pretty clear which filter flows the most air (potentially making the most power) but what's more important (and often overlooked or not even considered) is which filter lets the least amount of dirt into the engine while still flowing plenty of air. That was the premise of the story more than anything, horsepower included. The actual gain in horsepower between any of these filters (comparing same size filters of course) would be negligible. Ultimately the highest-flowing filter is no filter at all, but would you want to do that to your engine?  

Oh and the JK...The old 4.0L makes more torque lower in the rpm range than the new V-6. Meaning in most under-load driving conditions you'll need to be revving the new V-6 750 rpm higher than if you were driving the inline-six. If you regularly lugged the inline at 2000 rpm then you can expect the V-6 to require 2750 rpm or so. At highway speeds and higher rpms the rpm gap between the two engines closes a little because the 4.0L makes less power and the V-6 will be making more.

And the 2WD Wrangler? Who cares as long as they make the 4x4 version. In the future the 2-bys will be good less-expensive build-up Jeeps. Especially for those that want to swap the engine, tranny, t-case, and axles. Fact is that most Wranglers (and 4x4s in general) that come off the lot are rarely shifted into four-wheel-drive anyway.

Thanks Mr Editor. I guess it was really the trade-off between the dust capacity and cumulative effect that I wondered about mostly. I agree about the power thing. I took the intake horn off my stock cleaner and immediately felt a significant difference, especially low down - seems like half a gear. Jeep now cruises along happily in 4th or 5th where a change-down was definitely necessary in the past. But swapping the filter over to a high flow type gave no further gain that I could feel, so the couple of percent difference between the tested ones is nothing.

Why would Jeep supply a constricted air intake horn when a slightly wider one improves their product immediately, for no cost? Even give a bit better mpg, seemingly the holy grail for manufacturers now. Maybe Michael knows.

They still shouldn't sell a 2WD Wrangler. Just ain't right.

Thanks again for a must-read magazine. All of you there can raise a glass of mustard to yourselves.

By intake horn, I asume you mean that little curved thing that comes out of the filter box that curves upward? I have thought that thing looked a bit small, considering it is so much smaller than the intake tube. I'll give that a try tomorrow. Does it just pop out, or will cutting be required?  

It comes out pretty easy. Just twist it and it disconnects. I imagine this "horn" helps with reducing intake noise and to keep water out of the filter.  

Yes, it does come out by twisting, with a bit of force. Easy enough though. Intake noise increases a little, only once it really starts sucking. I noticed it the first few days, at certain revs, and then I didn't notice it any more. Not as significant as the change from warm asphalt to cold. Even with it off I'm guessing there's not as much room for water to enter as with the aftermarket jobbies, and it would be easy enough to get a plumbing pvc pipe elbow, cut the horn rear of the constriction, and put the elbow over it to mimic the original unit, but with a wider throat. I mean to get round to that one day. You could also continue it our through the side of the hood. OME's snorkel is just a smoother copy of the old days when we used to use plumbing pipe to take the air intake up the side of the windscreen of FJ40s. Works fine, just as well as the snorkel - you can even get an elbow with a drain plug - but of course it doesn't look quite as swish - unles you were driving some of the JP project vehicles. It also costs about $10, not $295.  

I pulled off that little airhorn. Made quite a noticeable little differnce. Can't complain about free power.  

Yeah, simple way to go, hey? Did you also find more low rev power? I'm changing gears a lot less, able to cruise along maybe 150 to 200rpm lower, sometimes even more so without lugging.  

Response is smoother all around, and there seems to be less strain when going up hill in 5th gear .  

Exactly what I found. Overall more driveable. My X came with little wheels, I upped them to 30x9.50, which made me use 4th a lot more, and was awful on those 55/60mph state roads - couldn't use 5th virtually at all. Changed to 3.53s, which make it rev a bit high for my liking (should change that a bit with 31x10.50 coming on Monday). But the air filter change brought the vehicle back to how it felt with the original wheel/gear ratio. Still revving higher, naturally, but smooth and easy-pulling, like it's finding a groove.  

For my 2 cents I have rusty's air tube set up with a k&n, I am makeing my own heatsheild but I donot think I really need one(got the alum free)

Anyways it works great, on and off road and it's cheap.I am guessing that a larger throtlebody would be even better with it.

Hi guys
New jeep owner here.  I have been to RUSTYS OFFROAD web site and looked at his prices and would like to ask a question please.  I need to replace the airfilter on my used 99 tj anyway and was going to a K&N filter for about 50 bucks. would changing to a full intake with K&N filter or just a K&N filter and take the airhorn off the stock box be the best for my 4 cyl. or does it not really matter.
Thanks
Announcedflea  

Truthfully, it doesn't make a huge differance either way. I think you will be happy with whichever you decide to go with.

Personaly, I like the full kit. For no other reason than it looks cool.. lol