Axle Back Questions and Deafening Cabin Noise

[Drunkenturtles]

I recently installed a Nxt Step performance axle-back on my stock 05 gt and I really like the low rumble and the way it sounds, but the cabin noise is deafening when cruising. it makes my mustang undrivable for long distances. When in gear at around 1500 - 2100 rpm the axle back makes the car resonate so loudly that it hurts my ears. I know it's supposed to be a loud exhaust, but being inside the car is louder than being right behind it- that just doesn't feel right.

Is there any practical way to reduce cabin noise? If not, I can return or sell the axle back as it's only one day old. Any recommendations for another axle-back that won't break the bank but sounds good and doesn't deafen my passengers?

Thx!

 

[Dino Dino Bambino]

You could choose between the Corsa, Borla Touring, MBRP, and Flowmaster Force II.

 

[tjm73]

I ran the Borla Stinger set up on my '05. It was just about perfect for me. Had nice tone and volume without being obnoxious. And it had almost no significant impact inside the car at cruising speed. Once ad a while on longer mild hills in 5th gear at 55ish mph it would get some drone. It had the power to pull the hill without downshifting, but I just downshifted to get the revs out of the drone zone.

 

[Racer47]

Mid mount resonators will fix most of the droning while not making it much quieter overall.

 

[Forty61]

If you like the deeper sound I loved my MAC mufflers on both my Bullitt and my CS, once I went catless they were way, way too loud but on a factory system they were great.

 

[Drunkenturtles]

Mid mount resonators will fix most of the droning while not making it much quieter overall.

I'll talk with my mechanic about doing that, besides that, I could call American Muscle cuz that's where I bought the axle back and see if they have any other recommendations. I'll also take a look at the other axle backs you guys recommended.

 

[Dino Dino Bambino]

Mid mount resonators will fix most of the droning while not making it much quieter overall.

The trick is to install the resonator on one bank further downstream. The sound waves will thus arrive at the mufflers out of phase and cancel one another.

 

[Drunkenturtles]

The trick is to install the resonator on one bank further downstream. The sound waves will thus arrive at the mufflers out of phase and cancel one another.

So would I need to weld in a resonator before the axle back? And why only one side if they are both independent of each other - like wouldn't one muffler still resonate with the engine?

 

[tjm73]

You could also research and have a set of "J tubes" (aka Helmholtz chamber/resonator) made.

 

[Racer47]

Offsetting the resonators has a slight benefit. It will not make the sound out of phase. The wavelength is way too long for that. Hemholtz can work but it is not easy to get it right. Thats why no one actually does it. Guys just talk about it.

Just search mid mounts. Theres a ton of threads on it. If you still need info, I can take a picture of my set up since the car is up on jack stands right now. I used two of these and it completely eliminated the drone.

https://www.summitracing.com/parts/VPE-1792

You place one on each pipe after the h and before the bend going over the axle.

 

[JEWC_Motorsports]

I had NXT on my 08 for about a week. Installing resonators with them did nothing. They drone horribly.

 

[07 Boss]

 

[Drunkenturtles]

okay, I'll look into mid-mount resonators to stop the drone. Though, maybe I should just switch up my axle back and save some money. What about the Pypes Pype-bomb axle back? It's about the same price and has the sound qualities I'm looking for. It's in the 300 dollar range and makes the exhaust note more aggressive. Maybe a full muffler delete might help with the loud, but low drone.

 

[Drunkenturtles]

I had NXT on my 08 for about a week. Installing resonators with them did nothing. They drone horribly.

I'm worried about that. I might spend 120+ on installing resonators and just end up wasting time and money.

 

[tjm73]

If price is your driving force, you will be stuck with less properly engineered options that will have varying degrees of the same issue.

 

[07gts197]

You could also research and have a set of "J tubes" (aka Helmholtz chamber/resonator) made.

Beat me to it. My 17 gt has a set near the tail pipes and they definitely work. I have a Bassani catback (no longer produced) that replaces the mid mounted resonator and deletes the axle backs. In videos I’ve seen its pretty loud even with cats but mine is pretty tame. Even on the interstate I get little drone. Actually I’ve been wanting to experiment and get muffler deletes to delete the j tubes to see how much of an effect it has on tone while recording it back to back.


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[Racer47]

okay, I'll look into mid-mount resonators to stop the drone. Though, maybe I should just switch up my axle back and save some money. What about the Pypes Pype-bomb axle back? It's about the same price and has the sound qualities I'm looking for. It's in the 300 dollar range and makes the exhaust note more aggressive. Maybe a full muffler delete might help with the loud, but low drone.

You are not thinking about this correctly. You want to spend another $300 to get the same type of axle back that will result in the same drone too? By the time you get a quiet enough axle back to stop the drone, it will be too quiet overall. Do something mid mount first. Than adjust the axle backs accordingly. Or read the dozens of posts on this forum that have already done the same thing and learn from their results. Damn near every reasonable combination has been tried and posted on this forum.

 

[Rick Simons]

The previous owner of my car had a local muffler shop replace the stock mufflers with Flowmaster 40's. I liked the way it sounded then and like it even more now with long LT headers, X-pipe, and high-flow cats. There is very minor drone at about 1200-1500 rpm under the right conditions, but it's not obnoxious at all.

 

[JEWC_Motorsports]

Corsa or Borla, only 2 that will sound good and not drone imo.

 

[Drunkenturtles]

You are not thinking about this correctly. You want to spend another $300 to get the same type of axle back that will result in the same drone too? By the time you get a quiet enough axle back to stop the drone, it will be too quiet overall. Do something mid mount first. Than adjust the axle backs accordingly. Or read the dozens of posts on this forum that have already done the same thing and learn from their results. Damn near every reasonable combination has been tried and posted on this forum.

Yeah, you're right, I get what I pay for tbh. I'll look into resonators, someone recommended a Vibrant Performance resonator and from the Q&A it will help with the drone. I'll look around the forums for resonators, but I'm happy to hear about any other good resonators. I'll fiddle with the axle back stuff after installing the resonators. Sorry, I'm not very knowledgeable when it comes to exhaust tuning.