Exhaust Drone

[Canadian 392]

Hey @AUSTX,

I've lived with both. My '22 XR (built late '22 model year) had no drove, just Hemi exhaust goodness.
My '24 Final Edition has the drone. Not too too bad in quiet mode, more apparent in loud mode and actually can be headache inducing and tiring on long drives, at minimum it's annoying/distracting on shorter drives.

I love the updated features on the '24 and it felt "tighter", steered better than my '22. The drone seems to be worse now as the exhaust gets a few miles on it (we're talking around 1000 miles). I don't understand it as I haven't experienced ths on a factory exhaust...ever...and I've owned over 40 cars/trucks, many of them high performance vehicles.

View attachment 49415

Not acceptable for an OEM exhaust straight off the factory assembly line.

Having to use quiet mode to mitigate that seriously excessive drone defeats the purpose of enjoying the noise a larger displacement V8 is expected to make. Even in quiet mode, in the lower RPM range, the drone is still fatiguing to your ears (on affected vehicles).

What the heck did they change for the 2024 model year?
Wonder how much the 2025s are affected?

 

[tjeeper]

It's not all '24s. Mine does not drone.

 

[Ray R]

My ‘25 seems fine too.

 

[Hayabusa]

My ‘25 seems fine too.

I am very happy for, and a bit envious of, y'all that landed '24 rigs that don't drone. I watched posts on aftermarket exhaust systems (AWE 1st choice, Borla 2nd) but most said none addressed the drone. I did not want to potentially put thousands more into it and not address the issue.

As the drone wore on me more and more I decided to step away. I've owned 17 new Mopar's over time and this is the first I've gotten rid of because I saw no solution and no effort from Jeep/Stellantis to address it...or even acknowledge it.

My hope is that, since Stellantis is trying to right the ship, future 392's will address whatever is causing it. In the meantime, I will enjoy a competitior's product I've acquired until Stellantis gets it act together. Unfortunate as I've had a great time as an owner on forums for the 392 Rubicons, Hellcats, and Vipers I've owned.

I'll stay on here and enjoy reading updates on the platform and about mods you guys make. If Jeep/Stellantis does get it's act together I'll be back here in a new 392 and back in a Mopar muscle car with a V8. I miss the glory days of MOPAR and dare I say...even when they were FCA

 

[Canadian 392]

Hi Everyone,

I have also emailed Jeep's CEO, Bob Broderdorf about the drone problem of the affected vehicles, along with my official Dealership Work Order whereby the shop foreman diagnosed the drone as "loud and untolerable" during his test drive with me.

I am optimistic Bob Broderdorf will initiate steps to help out his customer base for these affected vehicles.

Let's stay tuned....

 

[Ernesto]

Hi all,

Greetings once again from the UK.

I have owned my 392 now for 4 months. I have done 4000 miles without any issues. Average mpg is 16.5 and on a motorway run I see over 17 mpg. My 2L Rubicon was around 18-19 mpg so not much better.

In general I love the car. The drone is more or less absent on long motorway journeys where I average around 70 mph.

The drone is an issue around town and on slower routes. It is not really an issue with the exhaust in silent mode.

I am mitigating it in the following ways:

1) Use off-road plus when possible with the paddles. Great fun but not ideal in towns or on the motorway
2) Switching into manual when on a 50 mph road (to avoid cylinder deactivation)

I have historically put an exhaust on sportier cars and would consider this on the 392. However, this must cure the problem or at least reduce it by 90%. Is there a consensus yet on this?

I have emailed a guy from the UK who is an exhaust guru. I am trying to determine what the route cause might be.

I do think we are all missing a trick here. Something simple we have not yet considered. However, I am currently without ideas.

To say my Jeep dealer is unhelpful is an understatement.

Please share any fixes, ideas, exhaust solutions you have.

In the meantime, at least my car is 100% without issue apart from this. That is more to be said for many cars.

 

[Canadian 392]

Hi all,

Greetings once again from the UK.

I have owned my 392 now for 4 months. I have done 4000 miles without any issues. Average mpg is 16.5 and on a motorway run I see over 17 mpg. My 2L Rubicon was around 18-19 mpg so not much better.

In general I love the car. The drone is more or less absent on long motorway journeys where I average around 70 mph.

The drone is an issue around town and on slower routes. It is not really an issue with the exhaust in silent mode.

I am mitigating it in the following ways:

1) Use off-road plus when possible with the paddles. Great fun but not ideal in towns or on the motorway
2) Switching into manual when on a 50 mph road (to avoid cylinder deactivation)

I have historically put an exhaust on sportier cars and would consider this on the 392. However, this must cure the problem or at least reduce it by 90%. Is there a consensus yet on this?

I have emailed a guy from the UK who is an exhaust guru. I am trying to determine what the route cause might be.

I do think we are all missing a trick here. Something simple we have not yet considered. However, I am currently without ideas.

To say my Jeep dealer is unhelpful is an understatement.

Please share any fixes, ideas, exhaust solutions you have.

In the meantime, at least my car is 100% without issue apart from this. That is more to be said for many cars.

Hi Ernesto,
Thanks for the input. To date, I have installed the Borla Atak, Borla S Type, and AWE. No improvement in the drone. Since your vehicle is affected by the drone problem, I do not recommend you try these systems as I you are unlikely to be satisfied with the results. I have tried j-pipes, experimenting with various lengths with a highly reputable exhaust shop, but no real success and you’re left with a bunch of j pipe exhaust bends under the Jeep which is already pretty crowded to begin with.

I emailed Jeep’s CEO and am waiting for his reply….

 

[Ernesto]

Hi Ernesto,
Thanks for the input. To date, I have installed the Borla Atak, Borla S Type, and AWE. No improvement in the drone. Since your vehicle is affected by the drone problem, I do not recommend you try these systems as I you are unlikely to be satisfied with the results. I have tried j-pipes, experimenting with various lengths with a highly reputable exhaust shop, but no real success and you’re left with a bunch of j pipe exhaust bends under the Jeep which is already pretty crowded to begin with.

I emailed Jeep’s CEO and am waiting for his reply….

Thinking aloud…I was forced to listen to my daughter’s k-pop music in the jeep. The base sounded like the exhaust drone. Is this related to the acoustics of the cabin or some piping of exhaust sound through the speakers. I think this was discussed before.

And why only at 1500-2000 rpm. It must be resonance. If it is then there must be a way to stop this. Need to give it more thought…..

 

[AUSTX]

Just throwing this out there...has anyone removed all the interior panels (especially in the rear cargo area) to see if there is any difference?

 

[Canadian 392]

Good suggestion. I removed the rear panels and added dynamat. Put dynamat + dynapad on the deck under the carpeting also. Doesn’t help with the low frequency drone we get from 45-75 hz. You need serious mass to dampen those frequencies. Does help with road noise however.

 

[Ernesto]

It would be interesting to swap exhausts from an affected and unaffected car. Logistically tough.

Also, are aftermarket exhausts generally rear silencers only? If they don’t work the issue must be from a part that isn’t replaced.

Anyone asked chat gpt?

 

[Ernesto]

Me again…I asked a guy who makes exhausts for high performance cars. Apologies if this has been discussed or obvious but his comments below:

‘It’s s difficult to say, but ultimately you have an unwanted frequency.
I think it could require an additional resonator, could be inadequate bracketry, but I think more so a mass/ weight balance. The mass helps with weight damping
You could experiment with different weights at different points of the exhaust to see if it dampens the vibration and this frequency.’

Just thought it might provide an additional piece of the puzzle.

 

[I-10]

Crickets from Jeep cares. They have never followed up.
The drone noise is really bad while in 4 low. Its not winning any points with my wife.

 

[Canadian 392]

Crickets from Jeep cares. They have never followed up.
The drone noise is really bad while in 4 low. Its not winning any points with my wife.

Hi I-10, and others,

Very upsetting, to say the least.

I will be sending a follow up email to Jeep CEO, Bob Broderdorf Monday morning about this drone problem, reminding him that we are waiting for his support for affected customers. I will keep everyone posted….

 

[BarneyM]

Hi I-10, and others,

Very upsetting, to say the least.

I will be sending a follow up email to Jeep CEO, Bob Broderdorf Monday morning about this drone problem, reminding him that we are waiting for his support for affected customers. I will keep everyone posted….

I haven't read all the posts here but I am curious. Has anyone climbed under the Jeep and checked closely if the exhaust is contacting the frame/body anywhere. It's strange some have the problem and others do not.

 

[Canadian 392]

Great suggestion. I have checked, my exhaust shop has check, and the dealer had it for a few days examining from the motor, motor mounts, cats, and remaining exhaust parts. Nothing was found to be contacting....

 

[BarneyM]

Great suggestion. I have checked, my exhaust shop has check, and the dealer had it for a few days examining from the motor, motor mounts, cats, and remaining exhaust parts. Nothing was found to be contacting....

I assume this included the mounting points with the rubber isolation bushings inside. Could be a problem inside one of those?

 

[Canadian 392]

I assume this included the mounting points with the rubber isolation bushings inside. Could be a problem inside one of those?

You mean the mounting studs running through the rubber bushings perhaps contacting the metal housing or maybe the bushings are hardened and transferring the vibrations? From what we could see, this was not a problem.

 

[Agent WD-40]

I found a solution to my drone problem. It started when I switched to a Borla S-Type exhaust but I've completely solved it by adding some MRT ProSound mufflers (replacing the Borla mid muffler & switch fire crossover section). These mufflers specifically target the 120 Hz drone that occurs around 1900 RPM in V8 engines and work as advertised.

I didn't have a drone problem prior to adding the Borla S-Type exhaust. It wasn't terrible when I switched to Borla but it definitely added a boomy drone tone that you could hear right around 1900 RPM.

MRT was awesome to work with and they knew exactly how to solve the specific issue I had. They recommended their ProSound mufflers because they were designed to target the 1900 RPM drone I was having. My issue wasn't specific to 4-cyl mode, it was happening in V8 mode right around 1900 RPM.

Overall I like the modified Borla + MRT exhaust even better than before - it's the perfect balance performance sound and zero drone. Makes the system easier to live with every day with the valves open.

Borla S-Type Impressions vs Stock:
1. It’s noticeably louder than stock but not excessively so.
2. It sounds much deeper than stock. Smoother and more bass heavy sound character. I really like the tone.
3. Quiet mode works well. Not as silent as stock but definitely still a real and very effective quiet mode.
4. The black tips and muffler are tucked up much higher and a lot better looking than stock.
5. It manages the sound in V4 mode well. The transition is a bit more pronounced than stock, but very well managed. I’ve had and heard other vehicles with cylinder deactivation and aftermarket exhaust that were way more annoying in the transition between V8 and V4.

Borla S-Type with MRT ProSound Mufflers in Mid Section:
1. Overall it sounds a touch deeper than regular Borla S-Type but still retained a strong performance sound.
2. It’s a bit more mellow below 2.5k RPM but wakes up above 2.5k RPM and doesn’t seem to have lost much volume there.
3. It smoothed out the booming drone tones that happened around 1900 RPM (specifically the 120 Hz / 1900 RPM peak).
4. The transition between 4 cylinder and 8 cylinder mode is less pronounced than with the regular Borla system. It was OK before but this is a noticeable improvement.
5. Quiet mode is slightly quieter now and sounds exactly like stock quiet mode.
6. Has a deep performance tone at all RPMs but volume levels build a more gradually than before which makes the system overall more enjoyable to me.
7. MRT did the install and the welding and the quality of their work was amazing - all 304 stainless and excellent quality welds

 

[Canadian 392]

I found a solution to my drone problem. It started when I switched to a Borla S-Type exhaust but I've completely solved it by adding some MRT ProSound mufflers (replacing the Borla mid muffler & switch fire crossover section). These mufflers specifically target the 120 Hz drone that occurs around 1900 RPM in V8 engines and work as advertised.

I didn't have a drone problem prior to adding the Borla S-Type exhaust. It wasn't terrible when I switched to Borla but it definitely added a boomy drone tone that you could hear right around 1900 RPM.

MRT was awesome to work with and they knew exactly how to solve the specific issue I had. They recommended their ProSound mufflers because they were designed to target the 1900 RPM drone I was having. My issue wasn't specific to 4-cyl mode, it was happening in V8 mode right around 1900 RPM.

Overall I like the modified Borla + MRT exhaust even better than before - it's the perfect balance performance sound and zero drone. Makes the system easier to live with every day with the valves open.

Borla S-Type Impressions vs Stock:
1. It’s noticeably louder than stock but not excessively so.
2. It sounds much deeper than stock. Smoother and more bass heavy sound character. I really like the tone.
3. Quiet mode works well. Not as silent as stock but definitely still a real and very effective quiet mode.
4. The black tips and muffler are tucked up much higher and a lot better looking than stock.
5. It manages the sound in V4 mode well. The transition is a bit more pronounced than stock, but very well managed. I’ve had and heard other vehicles with cylinder deactivation and aftermarket exhaust that were way more annoying in the transition between V8 and V4.

Borla S-Type with MRT ProSound Mufflers in Mid Section:
1. Overall it sounds a touch deeper than regular Borla S-Type but still retained a strong performance sound.
2. It’s a bit more mellow below 2.5k RPM but wakes up above 2.5k RPM and doesn’t seem to have lost much volume there.
3. It smoothed out the booming drone tones that happened around 1900 RPM (specifically the 120 Hz / 1900 RPM peak).
4. The transition between 4 cylinder and 8 cylinder mode is less pronounced than with the regular Borla system. It was OK before but this is a noticeable improvement.
5. Quiet mode is slightly quieter now and sounds exactly like stock quiet mode.
6. Has a deep performance tone at all RPMs but volume levels build a more gradually than before which makes the system overall more enjoyable to me.
7. MRT did the install and the welding and the quality of their work was amazing - all 304 stainless and excellent quality welds

Terrific.
Is there drone between 1400 - 1800 rpm, low range boom in the 45-75 hz, on deceleration range with the MRT modifications? Also, no drone even when the system is completely warmed up after driving for 10 min?