Need help choosing a muffler

Discussion in 'KJ General Discussion' started by kavno, Dec 31, 2013.

  1. kavno

    kavno Full Access Member

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    I'm new here, and I have an '02 4x2 (unfortunately). I want to replace the muffler (not a full cat back b/c im broke as hell...) I'm looking for a deeper rumble but nothing over the top, just more aggressive and a bit louder. One that adds some low end torque would be nice. Also any advice for approaching 150k miles? I also plan to convert it to 4x4 eventually.
     
  2. streetglideok

    streetglideok Full Access Member

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    Reducing backpressure tends to rob low end torque, FYI. It alters the flow characteristics of the engine, leading to reduced flow at low RPMs, while enhancing flow at higher RPMs. One misconception that I'll make sure you know the truth on: You can not make a V6 or a 4banger sound like a V8, without adding more cylinders,lol.
     
  3. 02blue

    02blue Full Access Member

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    Can't vouch for this exact Jeep kit (below) as I have a Borla Dual catback on mine but the Heart throb deep tone dual kit I put on my 98 Ranger has held up well for 6 years. Still sounds great, not quite V8ish but nice rumble. The Jeep one below has a muffler my Ranger just has two glass pack muffler tips. Ranger (4L OHV) probably has a bit more sound for many people but I like it. Their prices are pretty reasonable and quality seems very good.

    Truck Cat-Back Single Kits

    2002-2005 Jeep Liberty 2-1/2" Cat-Back
     
  4. ridenby

    ridenby Gold Supporter

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    I cut the stock muffler out and replaced it with a Thrush glaspak,had to use a little piece of pipe cause I miss measured,otherwise it went right in. Sounded good.
    [​IMG]
     
  5. Jerpaderp

    Jerpaderp Full Access Member

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    Unbolted my muffler and took that thing off. Sounds AMAZING!! And, you can always bolt back on if you don't like it. It also takes a surprising amount of weight off...
     
  6. 02blue

    02blue Full Access Member

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    I did the same thing with an old 75 Ford that had a 302 in it and a thrush glasspack. Even pulled the cat and had a straight pipe all the way back. it did sound great but very loud.

    I'm thinking NO muffler would be unbearable in my Jeep. With my commute I'd get pulled over pretty quick with out a muffler but would sound pretty cool. Like Streetglide said the muffler was designed to be there so not like my old Ford and it will never rumble like a V8.
     
  7. wheeee32

    wheeee32 Full Access Member

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    Do a quick search on youtube. There's several vids on there with different mufflers for the KJ.
     
  8. tommudd

    tommudd Moderator Staff Member Moderator

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    All an aftermarket muffler gives you is some extra noise, and yes they are designed to have backpressure so removing the muffler just cuts your power down even more.
    Get a Magnaflow or something like that and enjoy
     
  9. streetglideok

    streetglideok Full Access Member

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    I personally like the quiet sound of the stock muffler. Bad parts are, it lets me here scraping easier and a very vocal wife that accompanies the scraping noise,lol
     
  10. 02blue

    02blue Full Access Member

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    Sometimes it's tough to tell the difference between the scraping and complaining ain't it?:jawdrop:

    Did I say that out loud?
     
  11. bassmanbob

    bassmanbob New Member

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    Flowmaster Super 44 is what I have been running for around a year now, super sexy sound! Also heard the Dynomax muffler sounds very similar but is about 30$ cheaper.
     
  12. CactusJacked

    CactusJacked Full Access Member

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    lol, just gotta love the "engine needs backpressure" myths that get spread around the different forums. Backpressure is a bad thing for engine performance (low end torque or hi rpm hp), period. And backpressure has nothing to do with torque, "scavenging" does. The issue about what affects torque is the diameter of pipes you use, not getting rid of a restrictive power robbing muffler. Our Jeeps, and most factory cars for that matter, have the type of mufflers it has because the majority of owners want a quiet exhaust, not because that's what the engine wants. Read this explanation (the whole thing) about how exhaust works, and what changes what: Exhaust and backpressure
     
  13. tjkj2002

    tjkj2002 Full Access Member

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    While the exhaust pulses is what directly effects your low end torque and such just by changing the muffler to a less restrictive muffler drastically changes the pulse/back pressure leading to loss of low end torque.

    Now if you spend many hours(sometimes days even) on a dyno testing different exhaust systems(custom made not aftermarket made) you can gain some low end and all that but most are not willing to spend a couple of thousand dollars doing that.


    Oh and changing the back pressure can and will effect the engine and with a stock tune it will be all negative effects like lower power and lower mpg's.


    And yes my exhaust has been drastically changed and yes I have lost low end power but had to modify the exhaust for clearance issues.It's all a trade off.
     
  14. tommudd

    tommudd Moderator Staff Member Moderator

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    High horse power Camaros/ Mustangs etc of late maybe but lower HP engines like ours is different
     
  15. streetglideok

    streetglideok Full Access Member

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    So much wrong here, I don't know where to begin. The problem with reducing exhaust backpressure on a stock engine, is that you will over-scavenge the cylinder at low RPMs, causing a reduction of power(torque). Hence you need to maintain backpressure on stock cam timing, and cam grinds to maximize performance. It can be shown time, and time again on a dyno, that reducing backpressure reduces low end power without engine mods being performed. Running too large of exhaust pipe has the same effect, it reduces backpressure due to less restriction. Now if you ran 1.5" exhaust, then yes, you would have backpressure, and a whistling fart machine. In the end, it doesn't matter what amateur website you link, if it is wrong, it is wrong. Play with cams, and exhaust, and tuning more and you will understand. I've probably built more exhaust systems than everyone on this site.:bowroflwerd6:
     
  16. kavno

    kavno Full Access Member

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    thanks for all the replies. I'm still deciding if it's worth the investment. I just finished painting my wheels and will have a pic up here soon. I'm also going to undertake a 4x4 conversion because I would like to say ive done it. im going to post progress pics and info as it gets done. probably ask for advice too. but I was under the jeep today and was looking at everything. I dont think it will be too terrible of an undertaking money permitting.
     
  17. CactusJacked

    CactusJacked Full Access Member

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    My muffler was shot, so I figured why not put on a better flowing one. I used a Magnaflow, stainless. It has a bit of a rumble outside, a little bit less inside, but almost totally quiet when cruising on the highway. Not annoying in the least. It's considerably smaller than the stock monster muffler, progress pics below. Cut the flange off the original muffler, welded it to the new, and added a section after the muffler to make up for the shorter length. Did I notice a gain in performance? Not that my butt-dyno could really tell. Did I notice a loss in power or torque? As expected, NOPE!

    [​IMG]

    [​IMG]

    [​IMG]
     
  18. LetFreedomRing

    LetFreedomRing Full Access Member

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  19. KJ zGal

    KJ zGal Full Access Member

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    Mine has an Aero Turbine 2525 muffler on it...it's loud, has gotten me pulled over a few times, but never any tickets. I guess the fact that I am a woman driving a noisy stickshift Renegade just confuses the cops so they let me go...can't guarantee the same for anyone else though =P This is an older video, but it still sounds the same.

    2002 Jeep Liberty Aero Turbine 2525 Muffler, 2 Months Later, After Welding - YouTube
     
  20. CzarKJ

    CzarKJ Full Access Member

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    I went through this the same time as letfreedomring. I ended up with a MBRP stainless cat back system. They sell the mufflers alone though. Works great sounds great. No noticeable loss of power. Louder than I intended but hey you only live once haha


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