What happens when you upgrade your Jeep's air filter and exhaust system?


Juggernaut

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What happens when you upgrade your Jeep’s air filter and exhaust system? I want to open it up with a dual exhaust but have not decided what of air filter yet
 

BLACKJKU

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Your air filter doesn't have any thing to do with the exhaust unless the filter is plugged with dirt then the engine will just starve for air.
 
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JKTim

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Chrysler engineers have the intake system dialed in for maximum filtering and flow. Using a good name brand filter is all that is needed at that end.
Others will chime in about exhaust upgrades.
Check this link out.
 
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MacGuyver

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Chrysler engineers have the intake system dialed in for maximum filtering and flow. Using a good name brand filter is all that is needed at that end.
Others will chime in about exhaust upgrades.
Check this link out.
Yep, Stay far far away from K&N kinda filters that allow "extreme air" or some crap. Just a way of allowing debris into the block.
Project Farm youtube has a demonstration of various air filters and K&N was really bad. Same kinda thing with cold air intake, just don't.
Stick with stock, save a jeep.
I have no opinion of exhaust.
 
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Chris

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Nothing substantial happens, trust me on that.

An air intake will do nothing whatsoever on your JK as the factory airbox is not a weak point.

A cat-back exhaust will do nothing either. Some will claim a 5 HP gain or something silly, but that's not something you can actually measure on a dyno as such a small number can be chalked up to nothing more than variables in ambient temp, engine temp, etc.

If you're looking to gain more power, you're going to need to spend more money.

Getting more air into the engine can increase power, but only when you open up the entire air pathway. That would mean intake, bigger intake manifold plenum / runners, ported head, bigger valves, higher compression, etc.

Simply bolting on a cold air intake will do nothing whatsoever on these engines.
 
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BLACKJKU

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Nothing substantial happens, trust me on that.

An air intake will do nothing whatsoever on your JK as the factory airbox is not a weak point.

A cat-back exhaust will do nothing either. Some will claim a 5 HP gain or something silly, but that's not something you can actually measure on a dyno as such a small number can be chalked up to nothing more than variables in ambient temp, engine temp, etc.

If you're looking to gain more power, you're going to need to spend more money.

Getting more air into the engine can increase power, but only when you open up the entire air pathway. That would mean intake, bigger intake manifold plenum / runners, ported head, bigger valves, higher compression, etc.

Simply bolting on a cold air intake will do nothing whatsoever on these engines.

I did notice a little Performance gain when I put the Viper TB on my JK .
 

Chris

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I did notice a little Performance gain when I put the Viper TB on my JK .

You will definitely feel a little bump in throttle response. My guess is if you look at the results on a dyno what you will see isn't so much a gain of power but increased throttle response due to the power band having been slightly moved around.

I try to explain things using the bottleneck example to people.

If you open things up with an air intake, it's the same as taking a 2-lane highway and converting it to 4-lanes for 3 miles, but then having it merge right back into 2-lanes after that. All you're essentially doing is moving the bottleneck further up the road.

The real gains come when you expand the entire thing.
 

dcooper45

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I saw a youtube video a while back were a guy actually dynoed his jk, put cold air intake and exhaust on it and then dynoed again. He was happy with his peak 8hp gain. Prob spent $1500 by the time he paid for dyno twice.
 
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My experience:
All Cat-Back systems work. Better power.
No Cat-Back system works at the speed (RPM) at which you drive.

Breathing is important. Watch the Gale Banks Video on YouTube. But remember the cost/benefit of any changes you make.
That stuff will make no difference when you are stuck and your stock Jeep can get you a speeding Ticket.
 

Boosthead

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I installed a catback on both my JK and JKU and they feel peppier and doesn't seem to work as hard going through the rev range.
 
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Ever think you were descending when your GPS showed you were actually ascending? The Butt-Dynamometer is just not accurate.

So I read the literature, saw that their own dynamometer showed that their cat-back, muffler and 'intake' worked! and I installed them. In spite of the fact that their own dynamometer showed it only worked 3,000 RPM above and beyond where the engine runs under normal driving conditions, meaning I paid a lot for sound.

I will install a snorkel because, over time longer filter changes will pay for it. And I've water come onto the hood of my JK.