Let's Talk JK Intakes & Exhausts

Who is running something other than a stock JK exhaust or intake? I'm starting to do some research on both and curious of your opinions.

I like the MBRP Offroad Exhaust since it relocates the muffler in front of the rear axle. Anyone have this? It's kind of pricey though.

Does anyone have a CAI? Like a lot of stuff I read online about Jeeps, opinions are all over the place. I see a lot of negative statements like snorkels are really the only true CAI or CAIs are bad since you could potentially get more water into the motor.

Anyways, I was just curious what you all have and if you have any comments??

Thanks,
Art

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that's what I think about them.

I perfer Magnaflo exhaust and AFE cai. I haven't done them yet, because I have other up grades I want to do first...regear and program then CAI and Exhaust.

Thanks for the feedback. Any comments on the Banks or Volant CAI? Seems like those would protect against water a little better since the filters are semi-enclosed - a greater risk for water issues (hydrolock) seems like the only downside to CAIs from what I read online, but I'm not a big fan of playing in the water anyways.

CAI will have water issues if you plan on going through water deeper than 3' which would be at the bottom of head light depending on lift & tires. I have Airaide CAI & MagnaFlow Catback.

i have an airraid and have been really happy with its performance and love the sound it makes when you get on the gas. i also go the cover for it that is supposed to keep out water but i would think that does more in a pouring rain than if i tried to cross water. either way i don't plan on testing it out.

I havent done the CAI yet but i went with the MBRP exhaust it not the offroad just the stainless cat-back. if your looking for sound then you should probubly go with the magnaflow or flowmaster i like the MBRP because it has a nice sound and to me it seems to have improved the perdormance a little. of course i also added the superchips programmer so that helped. One suggestion, what ever exhaudt you go with, get it welded. i just went with clamps on mine and it rattles at the connections. drives me insane. i can't weld otherwise it would be.

Thanks for all of the feedback. I haven't decided on what I'm going to do yet. Right now I'm thinking the Banks CAI and not sure about exhausts. These are future mods since the whip marks on my back are are still healing from the beating I took at home after buying the suspension lift a couple months ago!

Magnaflow just came out with an off road exhaust system for the JK. I don't know how it looks, but the add says it dumps before rear axle. In the hotrod market, magnaflow had larger HP gains then flowmaster or edlebrock, so I would assume the same here. They are not annoyingly loud with good sound and flow great. If you are planning a tune, Get the CAI and exhaust first so fuel trims can be properly set. (neither mod requires it unless your bumping the fuel injector size or getting new MAF) CAI getting water in it from rain is a no issue. I ran a 2.5 " CAI intake from the inner fender on the stang (which was lowered) with no problems for years even going through puddles on the road.

Hope it helps.

Here's something to read in regards to intakes.

http://www.jeepforum.com/forum/f9/faq-cold-air-intake-558437/

A CAI setup can still ingest water if you're going through it too quickly. You don't have to submerge the filter from wading in 3+ feet. If you still decide to get one, I would recommend a pre-filter for added protection.

For the exhaust, I like the MBRP offroad system which relocates the muffler. Any setup that puts the muffler in the rear or had pipes sticking out the rear has a higher chance of getting damaged while wheeling. MBRP posts dyno charts to back up their claim (which few vendors do for JK specific systems) and RIPP uses their exhaust for supercharger kits after doing some research and tests. If I had the coin and finished my wishlist of installs I would look into getting this exhaust. They have several options in finishes so you can pick up their cheapest kit for a reasonable price.

Did You see the mustang CAI? That was cool. I wonder if that would work on the JK. As for the article, learn something new everyday. Thanks.

I have to agree that for the most part, CAI alone don't do much. When I had my '03 f-150 supercrew, I added CAI, larger diameter MAS, 10 mm larger granatelli throttle body, converted to true dual exhaust with Gibson headers, plus a superchips programer. I can tell you that before all the above I could almost never spin my tires (powerbraking). Afterwards, I had little trouble powerbraking and the difference in throttle response was huge. I never got around to getting any dyno #s.

I still miss my f-150

after the jeeps paid off, I'll get another full size truck and start the modding and spending all over again

Catback is a waste of money, buy a Magnaflo tubular muffler off Summit, have it welded in front of the axle, done.

terrahawk wrote:

Catback is a waste of money, buy a Magnaflo tubular muffler off Summit, have it welded in front of the axle, done.

X1000! Unless you are replacing the whole exhaust from manifold back and increasing, catback don't do shit!

And goes the same for CAI, ALL the extra air don't mean a damn thing if you get it back out of te engine. CAI and larger exhaust go hand and hand ask any diesel owner.

An engine is just a big air pump no matter how fancy they get you still have to get ALL the air you put in, out.

Again, thanks for the info. I had seen some of the anti-K&N/CAI opinions before and is why I was curious on your opinions.

I have to admit, I haven't researched it much, but what exactly is meant by "cat-back"? I have heard that term often but never really understood what it meant. I am aware that this refers to the portion of the exhaust from the catalytic converter and back to the tail pipe/outlet, but what is being done here with a "cat-back" system?

Cleaner bends and sometimes large pipe, full flow muffler

You're replacing the exhaust from the catalytic converter to the muffler...cat back

The theory behind the cat-back systems is that the will allow your engine to more easily expel exhaust by reducing the back-pressure in the exhaust. The larger pipes, cleaner bends, and free flowing muffler (as Robert mentioned) equate to a less turbulent, less restrictive flow of exhaust gasses.

The reality is that the increase in flow after the catalytic converter has no significant effect if the flow up to and through the catalytic converter is less than the flow after it. To be most-effective the entire exhaust from the manifold to the tail-pipe needs to be replaced in order to minimize restrictions. Replacing all the components after the catalytic converter may yield some improvement, but more often than not what the cat-back systems do is provide a nominal increase in power while giving the vehicle a more aggressive (less mini-van) sounding exhaust. In a topless and door-less configuration, traveling at 70 mph, this change in sound nay not be noticeable. At lower speeds though, particularly from outside the vehicle it would be significant. I would also think that with a hard top on the sound change would be noticeable as well.

I would imagine that the biggest improvements in a cat-back for Jeeps would be in the ground clearance for wheeling. The stock muffler is somewhat vulnerable to impact as the rig comes off of obstacles. With larger aftermarket rear bumpers this risk is sometimes reduced, but still present. For me, I will continue to run the stock exhaust until such time normal usage or trail-induced failure results.

Yea, what the engineer said!

Just take it all off.

matinau wrote:

Just take it all off.

I agree. It takes 5 minutes to take off the muffler and it is free.