Does K&N FIPK on 2000 4.7 liter V8 make my Jeep louder?

Dave,

The increased sound level will be of different character, than a less restrictive exhaust would be. You will definitely notice something at first, but after a while maybe not at all. If you want more specific information, I am afraid you will have to find someone, who has it installed already, and actually listen. It's too bad they don't have a sound recording to go along with the dyno graph.

Imho, the percentage increase shown is not worth the expense, unless you are towing something and want all the power you can get, or are serious about fuel economy. There are likely to be economy gains with this device too.

Earle

Not to mention incresed 'crud' making its way through the air filter and into the engine.. Bottom line is K&N is a less restrictive filter. It lets more air in, which lets more 'crud' in. Take the air filter off your engine, drive around the block and see if you notice a power difference worth paying for.

Carl

The newer Grand Cherokees also have a resonator on the intake that you would be losing. I assume that it is there only for the sound reduction.

Also..

If you examine the chart you will see almost no improvement at the RPM levels where I generally operate my '02 WJ.

Are you actually trying to talk some sense into me? Don't confuse me with the facts when my mind is already made up.

But you know, you're dead right. I have been coveting the thing for a few days now and almost convinced myself I needed it. But coincidentally I hadn't been driving it for the same few days. I got in it today and drove about 40 miles total, and am reminded that it has plenty of power. And even driving over Vail pass and the approach to Eisenhower tunnel (between western and eastern Colorado) over Thanksgiving pushed thing thing only to

While it would be great to have, I just don't know how often I'd really notice having it.

Dave

I wonder if this is actually true. I would think that because of the recent high price of gasoline, if it was true why wouldn't K&N market that fact when they obviously market increases in power.

Dave

K&N has a LOT of information on their site about filtration--explaning why their filters are both less restrictive AND better filtering. Is there any reason to believe they are lying?

It seeems reasonable that it is possible to improve apon the standard paper element air filter, and that's what they've claimed to have done.

Any comments?

Dave

I certainly found it to be true when I put one of their filters, a Turbo City air tube, and a cat back system on my four cylinder Wrangler. I record the mileage and amount of fuel with every fill up, I am getting 22-25 mpg, and I live in the mountains. I don't mind the economy benefit, but I was looking for 10-20 hp gain in power, like it said in the ad. :^(

Earle

Dave in Colorado proclaimed:

Is there any reason to presume that marketing claims are the full and total truth? Or is there possibly sufficient evidence to be somewhat sceptical of any marketing claim not backed up by independent verification?

It may seem reasonable, but that doesn't mean anything one way or another.

Those fancy aftermarket filters have been around for decades, EMPI, EICO, etc.

A cold air intake kit can help on vehicles that don't already have a good pickup for cold air--and drive in conditions where this makes much of a difference. If the filter is kept clean and maintained by the owner and has less air restriction [which is not a given] you get a bit more power...under driving conditions pretty rare on the trail.

On the other hand, the nice sealed box filters tend to keep just a bit more crud out of your engine with a pretty good compromise of air restriction vs protection.

I drive it at 3,000 rpm most of the time. This appears to be the best way to get economy out of the 2.5 litre engine, and yields a decent road speed. I have driven it in Seattle and Denver, rush hour, and lived. It keeps up pretty well, but passing is just a dream.

Earle

Sensible thinking Dave. One other thing, they are a real messy pain in the neck to clean and the cleaning/reoiling kit is expensive too.

KJK

: :

The more I think about it, the less I'm convinced there would be any economy gains. Can someone come up with a theory why this might be true?

It seems to me that the Fuel/Air mixture is determined by the sensors and the computer, regardless of how much or little restriction (within reason?) is on the intake or how much Oxygen is in the air, and is one of the reasons why EFI is fantastic in Colorado, where you can be driving at 4000 or 12,000 feet within a few hours--the sensors tell the computer what's going on, and it makes the adjustments X number of times per second.

Dave

I measure a consistent 25 mpg with my four cylinder Wrangler, after having installed a K&N and a cat back from Borla. I don't drive it like a little old lady either. As anyone who owns a Wrangler can tell you, this is pretty good mileage, even for the four cylinder model. I think what you're maybe overlooking is that the stock intake and exhaust restriction is not within reason. Why that would be, I don't know, but lots of these types of add-ons are sold every year, and not everyone who buys them is an idiot.

The problem with a theoretical analysis, which you seem to be attempting, is you don't have all the numbers, nor do you know all the factors which are likely to be important.

I think that the best intake upgrade, would be a paper filter with simply more surface area, to satisfy the people who are whining about contamination of the engine. Unfortunately, it would take up too much space, and I couldn't find one, so I used a K&N instead. If you don't want to install one, that is fine, but it is a waste of time trying to come up with theories, that it is of no benefit at all.

Earle

They work because the are less restrictive through the throttle transition. The larger surface area of the filter allows airflow on demand building the cylinder pressures through this transistion. The engine will only flow as much air as it needs, no more.

Have you ever seen a the hood scoop on a pro-stock drag car? Large, LARGE with a nominal opening. The purpose isn't to ram the air into the engine but to have more air available than the engine needs throughout the RPM range.

Add to the mix that the air intake charge is cooler than the underhood temp for a more dense air flow.

As for the filtering efficiencies of the filter media the K&N meets exceeds SAE testing standards. If you feel that you need better filtration you might try and AFE (ProGaurd 7), AIRAID, or AEM filter, all of which feature synthetic media that will filter consistently to 2 microns (as opposed to 6 or 7 for a gauze only filter).

As for the sound... If you plan on running an aftermarket exhaust system you will never hear the intake. If you don't it is the sound of Horsepower.

Happy Holidays All!

Carl wrote:

I had a K&N stock-sized replacement filter for a few thousand miles, oiled, etc.. Tossed it when I noticed a thin film of dust on the inside of the intake tube between the filter box and throttle body. What wasn't sticking to the tube was getting into the engine. Replaced with an OEM filter and voila, no dust on the intake tube inside surface. That's not theoretical, that's real-world.