Yeah I’m Not sure because when you google Jeep exhaust layout the jk layout comes up but not the tj and it showed a cylinder exactly like the one on the tj in the same spot and they call it a resonator but I’m not sure. Anyway I’m trying to decide if I should cut it off and put a 40 series flowmaster muffler on it or keep it and put the muffler on.
So I want to put a better sounding exhaust on my 4.0 LJ but I've heard that it won't last as long if I do so is this true?
- Thread starter Tzerambo
- Start date
Airjunky
TJ Enthusiast
After I rebuilt my 4.0, the first place I took it was the muffler shop. He put in a FloPro, said it would sound the same, but better quality. Definitely has a deep growl at idle. Then at higher RPM, it sounds like a 4 banger.
The old tailpipe interfered with the shock. Plus I thought it was too long. Solved both.
The old tailpipe interfered with the shock. Plus I thought it was too long. Solved both.
What is the quietest combination you have found so far? PO on my TJ made modifications that make it kinda loud at idle. I'd like to get it back to as quiet as I can, but I don't know how or what to ask for.
I'm still working toward finding a better muffler. I dislike making exhaust louder to "be manly" or to make the engine sound powerful. If the engine makes noise let it, if it doesn't I don't need to turn the volume up. Currently the quietest on the 4.0L that I've found is anything that keeps the cats. The stock cats provide adequate flow even for a boosted engine so there's little to no performance gain by removing them. For mufflers the Thrush Hush is louder than the stock LJ muffler I think but not much more. I have a supercharger on my engine and the blower can be heard out of the exhaust which is annoying. If I have time this summer I plan to buy several different mufflers to test on the khaki TJ to see what I can do. The quietest one will stay and get professionally installed.
There's a lot of good info over here: https://wranglertjforum.com/threads/quietest-muffler-for-tummy-tuck-and-mid-arm.28160/
LONGJP2
TJ Expert
Agreed. OEM is the best place to start if you are not already stock including all cats, muffler etc. Only other option would be aftermarket mufflers that are designed to be quiet, and potentially also something like this if you also were able to find a spot to weld it in before a standard muffler.
https://www.amazon.com/dp/B000E3VHWI/?tag=wranglerorg-20
That would be getting insane for a Jeep though, at least in my book!
I agree OEM is probably the quietest choice.
Part of my issue is I don't know what I have currently, or what OEM was.
The PO has changed it. From the weld job and current sound, I can tell it probably isn't factory have now.
If I go to a muffler shop and tell them I want to restore it to OEM, will they know what that means & have the parts to do it?
People like Engine Masters have done engine dyno testing where they crushed headers with a hammer until they were halfway closed and noted no difference in power output. The differences between mandrel bent vs mandrel pre-bent and welded would be indistinguishable.
I do believe it's more important with a boosted engine, as has been common consensus for decades. Forced air in = forced air out.
That being said, I'd never not do mandrel bent anyway. Looks better, it's more efficient on paper in flow regardless of practical usage. Just do that if you have the coin.
As astjp2 said, anything that necks down is restrictive. It just isn't enough to make any difference to 95% of engines. Venturi effect, it just speeds up and gets through.
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Yes, they should be able to do this for you. Assuming your exhaust manifold is stock, in good shape, and you keep that, then for a 2001, you need these other pieces. Here are examples of the pieces you need:
1) Front midpipe with 2 precats - ex. Walker 53461
2) Rear converter - ex. Walker 16085
3) Muffler and tailpipe of your choosing - whatever OEM replacements you choose.
You can go with whatever brand of “direct replacement” for each piece, they simply are designed to match the OEM fitment. Muffler shops typically carry a few brands, so you can likely choose what you like by quality, cost etc. You might have some pieces on now that can still be used, but if it is all welded up and you want OEM connections, then perhaps not.
On my 05, which is similar but uses different parts than the 01, I went Flowmaster for pieces #1 and #2 and Banks catback for #3. If I had an 2001, I’d check out Walker. The Magnaflow cats will be expensive and I’ve heard someone say to avoid Bosal, but that was second hand info, so who knows. There are a couple other brands as well, but I’m not familiar.
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I’m very pleased with the Banks Monster exhaust, it’s got a quiet tone to it with no drone and you can hear it when you mash the skinny pedal.
https://www.bankspower.com/i-798-mo...004-2006-jeep-wrangler-4-0l-unlimited-lj.html
https://www.bankspower.com/i-798-mo...004-2006-jeep-wrangler-4-0l-unlimited-lj.html
I also don't think you're hearing the blower out of your exhaust. That's pretty much impossible, everything is on the intake side. With a turbo, different story.
If you don't want to hear the supercharger you can dampen the sound through the intake with baffles. Otherwise most of the sound, assuming it's a Roots or twin screw type, is coming directly from the unit. There's no hiding that aside from putting some dynamat on the hood and firewall.
I love that sweet whine.
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I think Magnaflow has samples with audio u can hear on line.
Be careful with a loud exhaust, u don't want the annoying drone, that will make u a jeep nut case.
Be careful with a loud exhaust, u don't want the annoying drone, that will make u a jeep nut case.
The sound man!
The sound.. my heart is aching, I LOVE IT.
Any idea what's the name of the exhaust system?
There is only so much you can do to these motors. The stock system is pretty basic. I recently replaced a dead and corroded Dynomax with a 2.5" Flowmaster Laminar Hushpower 2 muffler and love it. These mufflers provide just enough back pressure to keep things working as they should, but enough flow as a glass pack. Sounds great and not loud at all at idle. Somewhat in between a Super 44 muffler and a magnaflow straight though. More importantly, it tucks in high above the bottom of the frame line and i have tons of room back there. High flow cats rather than gutted cats are advisable as well, unless you have a custom tune that doesn't use the feedback.
I think it is just the stock muffler when in normal mode.The sound man!
The sound.. my heart is aching, I LOVE IT.
Any idea what's the name of the exhaust system?