CJPP unbranded axle-back?

[Mustang_Lou]

To further add, drone is dependent on the RPM and the load on the engine. The gearing will only alter your speed at that RPM. Gearing alone has nothing to do with the drone - it'll only gets you there at a different speed.

Most car's I've experienced it on is around the 2,000 rpm mark, +/-.

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[Emt1581]

To further add, drone is dependent on the RPM and the load on the engine. The gearing will only alter your speed at that RPM. Gearing alone has nothing to do with the drone - it'll only gets you there at a different speed.

Most car's I've experienced it on is around the 2,000 rpm mark, +/-.

Like I said, I stay well above 2000rpm when driving so I'm guessing I won't notice anything continuous. But I'll intentionally see if 2000-ish can produce it.

I saw other replies saying the cut is really important and can produce different results. Both LMR and CJ's say to cut where the pipe is straight and immediately BEFORE the curve. Is this good advice or is another cutting location better?

Thanks

 

[BmacIL]

Like I said, I stay well above 2000rpm when driving so I'm guessing I won't notice anything continuous. But I'll intentionally see if 2000-ish can produce it.

I saw other replies saying the cut is really important and can produce different results. Both LMR and CJ's say to cut where the pipe is straight and immediately BEFORE the curve. Is this good advice or is another cutting location better?

Thanks

The cut won't make a difference except for fitment. Cut where the instructions say.

 

[Emt1581]

Installed them this afternoon. So far I'm loving them!!

The install wasn't bad except I didn't take the hangers off and I just muscled them into the rubber hole. That was a bitch. Otherwise, they went on pretty easy.

When I started it up it was like a totally different car. They are exactly what I've been looking for! Very deep and throaty. No real rasp and not obnoxiously loud either which is good. But definitely louder and much more aggressive than the stock pieces of shit!

That's another thing! When I took off the stock mufflers, those bastards were heavy!! I know someone already mentioned a weight difference but it's significant.

Now on to drone....

From about 1600 to 2200 I notice it's louder in the cabin. I'm not sure if this makes sense but I almost experience the sound as a perceived frequency rather than regular noise or vibration. And just as I thought I don't really stay in that range for longer than a second or two so it sort of blends in with the growl of acceleration. However, I do notice that up above 2500 it gets much quieter.

To be honest, this is my first sports/muscle car and my first aftermarket exhaust, so I'm not sure how to interpret all the aspects of the sound. I do know I had to watch myself a few times in traffic because I was revving the engine just to hear how great it sounded....and forgot that it could be pissing some people off or being interpreted as a challenge. It just sounds so good compared to the sleepy stock exhaust!! I also found myself driving a little more spirited than normal around town just to hear it. This is something I have VERY rarely done in the past because I prefer to get on it on the highway.

Again, the sound is EXACTLY what I was hoping it would be...not to loud, not too soft, throaty/growl... and I love that it doesn't sound like a fart can or a crotch rocket. Makes the car respectable and fun to drive! Money well spent!!

As for the stock mufflers, I feel like retiring them with some 5.56.

 

[BmacIL]

What you're describing is drone. As long as you are happy though! The first axleback I had did exactly the same thing and sounded similar. For my first exhaust I really liked it, but grew tired of the boominess in the cabin and slight drone.

 

[69mach1-395]

Installed them this afternoon. So far I'm loving them!!

When I started it up it was like a totally different car. They are exactly what I've been looking for! Very deep and throaty. No real rasp and not obnoxiously loud either which is good. But definitely louder and much more aggressive than the stock pieces of shit!

And just as I thought I don't really stay in that range for longer than a second or two so it sort of blends in with the growl of acceleration. However, I do notice that up above 2500 it gets much quieter.

Again, the sound is EXACTLY what I was hoping it would be...not to loud, not too soft, throaty/growl... and I love that it doesn't sound like a fart can or a crotch rocket. Makes the car respectable and fun to drive! Money well spent!!

Told you so...

 

[sw686blue]

From about 1600 to 2200 I notice it's louder in the cabin. I'm not sure if this makes sense but I almost experience the sound as a perceived frequency rather than regular noise or vibration. And just as I thought I don't really stay in that range for longer than a second or two so it sort of blends in with the growl of acceleration. However, I do notice that up above 2500 it gets much quieter.

And that my friend is drone. It's almost like 2 notes not in tune with eachother that cause dissonance. If this axle-back did not have drone, you would not perceive it in that 1750 to 2100 rpm range.

 

[Emt1581]

:cheers: After all your research in glad your happy with your choice! And don't worry about this statement "I'm not sure if this makes sense but I almost experience the sound as a perceived frequency rather than regular noise or vibration." It's actually not drone and it will practically go away once the system is sooted over a little. "Some" that are telling you that it is drone have never tried the axle-back out for themselves but love to promote something else.

I can't say whether it'll go away with soot or not but on the highway tonight my wife picked up on it REAL quick. It was the same response you get when you blow a dog whistle in front of a dog.

Was much more noticeable on the highway at higher speed in the same rpm range.

Doesn't matter a whole lot to me though because, like I said, I typically am not in that range much at all in my travels. However, for those saying there's nothing drone-wise, they are either deaf or maybe lucky.

 

[BmacIL]

I accurately described what he was noticing. It drones. I'm not surprised. I try to help people with their goals, I'm an engineer, and have helped or believe I have helped [MENTION=20357]Emt1581[/MENTION] with several other decisions. Clearly he was hesitant and the result is as expected. If YOU like it, and have no issue with it, great! Many people would have issue with drone or a boomy cabin sound. Oh and BTW, that stuff only lessens with soot build up. It never goes away. Oh and that tiny, tiny amount of resonance I mentioned and you quoted was eliminated once I replaced the flex pipe on the passenger side catalyst outlet pipe. So now, absolutely zero resonance at any rpm or speed.

Good day. I'll stay out of your thread.

 

[sw686blue]

I have them and they drone. I'm not sure why you say that they don't Bill. They may not drone for you, but they certainly do in my car. Unless you are north of 2500 rpms, they drone. Plain and simple.

 

[Emt1581]

Guess I'm both. There is a very specific hz range for drone and a dog whistle is not in it. If you say it's drone I believe you, no problems here, post up a sound clip. That's what reviews are for, people that actually try the product and report.

Just gotta wait for LMR to send me the review email. It'll be short but sweet and will definitely mention the specifics of the drone as well as how great it sounds out of the range of drone.

 

[Emt1581]

I accurately described what he was noticing. It drones. I'm not surprised. I try to help people with their goals, I'm an engineer, and have helped or believe I have helped [MENTION=20357]Emt1581[/MENTION] with several other decisions. Clearly he was hesitant and the result is as expected. If YOU like it, and have no issue with it, great! Many people would have issue with drone or a boomy cabin sound. Oh and BTW, that stuff only lessens with soot build up. It never goes away. Oh and that tiny, tiny amount of resonance I mentioned and you quoted was eliminated once I replaced the flex pipe on the passenger side catalyst outlet pipe. So now, absolutely zero resonance at any rpm or speed.

Good day. I'll stay out of your thread.

You've been extremely helpful. No need to leave.

 

[Emt1581]

Wanted to report back after a week of driving all over with these. They are keepers for sure!! I LOVE how they sound!! Just the perfect mix of deep, throaty, and growl!

Got me some weird attention today on the way to work though. Going down a two lane road I could see a tow truck obstructing one of the lanes so I downshifted and slowed down which made the exhaust roar louder as I drove past. This fire-police guy started flipping out, giving me the hand motion to slow down but almost hopping up and down as he did it, but I was only going maybe 15-20 at most. But because the pipes were loud I guess that lit the fuse on his tampon and equated sound to speed.

So while some may say they are cop friendly, fire-police might be another issue entirely.

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