I finally got my K&N air intake and installed it yesterday. It took a couple of hours, but with the great instructions, it wasnt as difficult as I thought it would be.

I already had a flowmaster installed previously, but hadnt seen too much power gain. The intake does make a big difference. It seems to have added new life to my old Xterra. I get much better pickup, and I find myself using a lighter foot on the gas pedal now. Hope that will help the gas milage too.

The only problem that I have is the sound. Although, it sounds Great on local streets, its fairly loud on the freeway. Or maybe i just need some time to get used to it. I drive quite a bit on the freeway, and the drone has been bothering me a bit. Is this something that everybody else has noticed with the Intake (or maybe the combination of the intake and muffler).

I don't really get any drone with my intake and Gibson exhaust, but the Gibson is known for being one of the quieter exhaust options. It does seem to have a certain resonance around 3000 rpm under load, but I don't really mind it. What took me awhile to adjust to was the intake hiss, but it's all good now.

Glad the upgrades worked out for you - I also found that the combo made a lot bigger difference than either probably would alone (certainly the exhaust alone didn't do much but sound) - synergy is good.

I installed my K&N FIPK II first. Then i went and installed my Calmini Cat back exhaust. I noticed the annoyingly loud drone of the combination. It does get annoying after a while but since i liek to listen to my music loud it doesn't bother me as much anymore. But reall if you think that is annoying never get a throttle body spacer. Godi wish I never installed that damn thing. It hisses on the freeway between 65 and 75 when I am just crusing. Accelerating and deaccelerating makes the noise go away though. But anyways back on topic, you will get used to it, it's really not that bad.

I too have the Flowmaster 40/K&N FIPK II combo...but to be honest, I haven't noticed that big of a noise difference as you have. It does give it a little better throttle response but that's been about it for me.

AS POSTED BY billyburger :
I too have the Flow master 40/K&N FIPK II combo...but to be honest, I haven't noticed that big of a noise difference as you have. It does give it a little better throttle response but that's been about it for me.

You know what I think it is .
I think that if you have a 5Spd you make more hp when using this two modes (cold air intake + flow master) than automatic transmition because they go through higher rpm`s and more often. You got 5spd vs 4spd which go gradually through the rps .

I'm using the FIPK GEN II kit as well as the Calmini cat-back, and I swear sometimes that I'm driving a different truck. Not kidding about the throttle body spacer though...that hiss takes some getting used to. I'm considering putting heat wrap on the hood and putting sound mats in the doors just to help get rid of it. I might go with the full SLR Throttle-body instead of just the spacer to get some relief from the sound. We'll see :rolleyes:

Thanks all for the replies. I think I have got used to the sound now, and as cobain913 said, loud music definitely helps. Every so often, I'll have someone sit in my X for the first time (since my upgrades) and comment on how loud it is now. One friend of mine even thought I had a bad muffler

But I'm really happy with the power improvements. I think the FIPK made a big difference, even on my automatic. I was looking at the throttle body spacer, but if it will only make it louder, I'm going to stay away from it.

I guess the next thing to do to boost power is maybe replace the plugs and wires. Any suggestions? From what I've read on the board, the sixth plug can be real tricky. I'm thinking I'll have that done at a shop and do the other five myself.

On a some what related note. Has anyone had any problems concerning senors with aftermarket intakes. I heard that the oil can damage the senors. I am planning on getting the K&N FIPK too, but before I do I want to know if anyone has had any problems.

I just finished my K&N FIPK2 and it took me 2 hours. I also have a Flowmaster 40 Delta on my truck. I don't know what noise difference everyone keeps talking about. With my windows up, radio off, and air off I notice hardly any noise difference in the cabin. With my windows down however, that is a whole different story.

The FIPK does not make a horrible hissing noise like everyone said. I can hear it sucking air if I am stading within 2 ft of the front left of the truck. Otherwise, I don't hear anything. My Delta muffler sounds awsome on the outside of the truck but is barely heard on the inside. When stomping on the gas I hear it in the cabin a tad. Nothing that would bother me. While cruising at highway speeds I don't hear the muffler or the intake in the cabin. If anything the tires are making most of the sound.

Have those of you who have bad hissing checked the intake for leaks and tightened everything up? It says to do that right in the directions. When I finished the install the wife was standing outside and I made mention I hope this shit works. I fired up the X and she was like "what is that suppose to do, I don't hear any difference" because I had kept talking about how it would make a huge hissing noise (as described on XOC). Needless to say, my install went flawless and I didn't need to tweak anything to quiet it down. The only snafu was that I broke my remote starter emergency cut off pressure switch on the hood. A new one is being sent to me free of charge though.

Installed mine this weekend. In the city a little difference slightly louder, same pitch. On the highway you can hear the thing sucking air pretty good (going to check hose clamps). When passing on the highway everyone notices. Had to try it, at 5k the engine sounds completly different. I didn't think the intake would make suck a big change in sound but I am prety happy with it. I talked to a shop in St.Cloud about a custom cat-back and quoted me $200 when I showed him the Calmini set-up. Added benifit is they will adjust the tone to your liking while assembling it. I know where I'm going to get that done, but I have to graduate and get a real job first. I see all this as motivation.