cold air, K&N vs. AEM

andrew c · **Joined:** Tue Jun 05, 2007 8:17 pm **Posts:** 24

I am probably going to buy a cold air intake, but i was wondering wich will give me more power, The K&N claims 8.5 and the AEM claims 13ish, but i think they dynoed it with a wrangler. has anyone dynoed with these on there kj?

csukoh78 · **Joined:** Thu Mar 08, 2007 10:34 pm **Posts:** 501

This topic has been covered a lot. Neither work, and will waterlock your engine should you ever ford. The best is the get an amsoil dry drop in filter and keep the stock airbox. Good luck. Don't waste your money on a plastic or metal tube.

SavageUrge · **Posted:** Tue Jun 12, 2007 7:45 pm

Look into an AEM DryFlow filter. I don't know what the drop-in's are going for, but the come styles are around $50

broncsrule · **Posted:** Tue Jun 12, 2007 11:38 pm

I had the K&N on untill this weekend. I put my stock box back on and have an Amsoil filter on order. I finally came to the conclusion that Arizona is just too dusty for the open element. It is a PITA to clean all the time.

By the way, you can by a cover for the cone to help keep water out of it.

Go with what you like, it is your JEEP!

CaKJFreedom · **Posted:** Wed Jun 13, 2007 12:50 pm

Yep, it's up to you.

I have a generic ebay tube with a K&N filter. I took it off in Moab and put the stock air box back in. There was a little gunk on the inside of the tube on the filter end. I think it was from overspraying the oil. But my mileage has dropped since then, noticeably. Long term, I know worse mileage is better than junk getting into the engine, but I miss the extra miles. I think I'm rambling.

JJsTJ · **Posted:** Wed Jun 13, 2007 1:08 pm

No "CAI" system I have seen yet will isolate the hot underhood air as effectively as the factory air box assy. Drop in a good air FILTER (K&N isn't much of an actual air filter until it loads half way up w/ dirt) and it will work fine. The Amsoil EAA201 is a great choice and drops right in.

Nan, YOu might try resetting to a baseline on your engine computer as it has learned how to work w/ your old filter setup. Search for it, but IIRC, you just disco the battery cables and Ground out the positive cable for a period of time and it will reset everything to the base parameters and start its relearning process over again. Please verify that process before attempting it.

Boi1ermaker · **Joined:** Tue Jan 24, 2006 1:44 pm **Posts:** 249

One of the first mods i did to my KJ was the K&N FIPK. In the month before i replaced the exhaust system, i didn't really notice a difference in power or fuel economy. If you look at K&N's own dyno chart for their 57 series FIPK for the KJ, you'll see that it doesn't start making a difference until you approach 3k rpms and has its most effect at 5200rpm. I don't spend a lot of time even at 3k rpm, and probably never touched 5k until i got my pcm flashed.

I don't live in a dusty area, so i wasn't having many problems with the cone letting too much by. But i wasn't really thrilled with having to re-oil it occasionally either. FYI for anybody with a K&N system with the RF-1048 cone. Amsoil does not make a direct replacement cone, but the EaAU6081 will work if you have the room. Its a little longer and slightly wider at the top than the K&N cone and so it was a tight fit.

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

If you stay below 3k rpm, the more effective mods are going to be an upgraded muffler, and take care of the decrease in diameter by it, and a ported throttle body. A better flowing drop in might help a little. These things don't make a better run out to the dragstrip change. They make it a little better down low, but that's what you're looking for. 4.10 gears also help a lot in the low range. They get you up high though. My interstate milage dropped from an average of 24 to 20 mpg when I went to 4.10's. My 45-55 mph is still around 24 mpg though. City is only 12-14, but could probably be up to around 15 with a different driver. The cones can help if you make a lot of other changes, and figure out a way to get a ton of cold air to it. I've had the best luck so far with a hood that dumps cold air into a K&N heat shield built up to seal against the hood better. I removed the little air dam so additional air would get to it from under the hood. Also, the normal air that gets to it around the radiator comes in. All this creates a high pressure cold area at speed, and a good source of air even at a stop. You can actually feel it pulling in a little air through the scoop as it idles. I found that better economy actually comes from leaving the bottom of the heat shield unsealed. I guess it adds a just enough gas to the slight increase in pressure to be noticeable. I've found that to get around a 5% power increase from ram air, you would need to be traveling at around 160 mph to create the 1 psi you would need. There are ways to create that additional pressure, but that discussion tends to start flame wars.

andrew c · **Joined:** Tue Jun 05, 2007 8:17 pm **Posts:** 24

Which one will give me more hp? I'm not gonna be going through rivers, so im not gonna have to worry about that. Will a k&n drop in give me more than a cold air? Surely not,...? Im fixing to get the liberty from my dad,... so I HAVE already bought, and installed a flowmaster 40 muffler on it. I STILL WANT MORE HP!!!!!! Im not going to put NOS on there,..the only other thing I can think of as far as performance other than Cold air is,....headers!! Will I have to take the engine out to install headers? One more question,...where can i get some headers from, for about $200? Pacesetter doesnt make any that i know of.

andrew c · **Joined:** Tue Jun 05, 2007 8:17 pm **Posts:** 24

Oh yeah,...its my first car. So it has to be FAST!!!

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

andrew c wrote:

Which one will give me more hp? I'm not gonna be going through rivers, so im not gonna have to worry about that. Will a k&n drop in give me more than a cold air? Surely not,...? Im fixing to get the liberty from my dad,... so I HAVE already bought, and installed a flowmaster 40 muffler on it. I STILL WANT MORE HP!!!!!! Im not going to put NOS on there,..the only other thing I can think of as far as performance other than Cold air is,....headers!! Will I have to take the engine out to install headers? One more question,...where can i get some headers from, for about $200? Pacesetter doesnt make any that i know of.

andrew c wrote:

Oh yeah,...its my first car. So it has to be FAST!!!

A good drop in will do at least as good as a CAI if you don't get extra cold air to it. There's actually a ton of stuff you can do. But I think you're going to have to have a reality check on prices. JBA makes a set of headers for the '05 and '06, but I don't know if it will fit the '07 or not. They're a couple times as expensive as what you're looking for though. I've got around $10,000 in modifications to my KJ without including the short block sitting in the garage. If you count that motor that I scorched on a quarter mile run, almost $15,000. However, It is FAST!!!

wendell · **Posted:** Sat Jun 16, 2007 8:11 am

Most people do intakes because they like to mod and tinker under the hood, they also look good and make an awesome sound at wot. When manufactures post numbers, they dyno tune with thier product for the best result, thats something a normal person can't do. An intake is only one part of a system, for the best results, you need to be able to let the spent gases out besides leting more air in, also enrich the fuel for added air. In other words, you need an intake, exhaust and a tune for real meaningful power upgrade. And yes, the benifit will be in the upper rpm range as lots of fast moving air is the secert to power. For lowend power, you need things like an under drive pulley, gears and a tune where the timming comes into play. The point being, just throwing on an intake won't snap your neck, but is a first step for a bolt on power package. Now the heart of the question, in my experience, AEM is the better intake, thier oil free filter is a God send. K&N is getting a good reputation for letting in as much dirt as air. AEM is the better system all the way around for my money. For dusty offroad conditions, nothing filters like a paper filter, also nothing restricts air like a paper filter. A lot of desert racers use AEM and K&N for better flow, but they rebuild thier engines a lot anyway. A quick way to clean the new AEM dryflow filter is to smack it, so on a bumpy offroad trail, the AEM cleans it's self every time you hit a bump, an oil guaze filter doesn't have that advantage as dirt sticks to the oil. I have both, K&N ands AEM, I like the AEM much better, I even ended up putting an AEM dryflow fiter on my K&N intake. I hope this helps and sorry it's so long.

andrew c · **Joined:** Tue Jun 05, 2007 8:17 pm **Posts:** 24

Thanks man,...thats ok. Thank you for taking your time to explain, I will probably get the AEM. Soooo,...if I put the AEM on and reset my computer it will give me better power? thoughout the rpm range?

wendell · **Posted:** Sun Jun 17, 2007 7:05 am

I don't have an intake on my kj yet, but in my experience from my other vehicles, you will get better throttle response through out. The biggest power gain will be at wot.