FM 40 series too loud and too much interior noise...

[7Kings]

I have a 2016 quad-cab with a 5.7 and just had a dual exhaust system fabricated by a local exhaust shop (was previously a single outlet). I really like the Flowmaster sound, but I thought I was asking for a Super-40 and the tech thought I was asking for an OG 40-series, which is what he installed. My fault for not double-checking before I signed off on the work, but live and learn... Not his fault and they did a really quality job on the fab and install. To his credit, he installed the muffler back near the rear axle, so it's not right under the cab.

So, the 40-series sounds really mean (sounds great) when you get on the throttle, but there's quite a bit of cabin noise when just driving around town - a little more than I'd like. When I'm on the Harley, the noise is part of the enjoyment, but the 40-series (and no rear resonators) is a little too aggressive for the truck to me.

That being said, I'm trying to figure out the best path forward. I was kicking around the idea of installing Dynamat sound-deadening under the carpet and across the rear cabin wall, which would just generally improve the overall interior sound levels, but I'm not sure how much that would help with exhaust sound. Alternatively, I can just have a different muffler installed and call it a day.

Thoughts? Recommendations? When I was a kid, I'd be stoked with the setup, but my 51 year old sensibilities prefer something a little milder.

 

[turkeybird56]

You could try and put the resonators back on, dampen some, but if U really wanna tone it down a bit, U gonna have to change out the muffler(s). Did U go true duals and 2 mufflers, or just single split into dual exhaust? Either way, U gonna have to tone down the muffler if U want less noise. Like I said, resonators may help, just not sure how much,. Like U, my days of big noises are done. Used to run dual Hush Thrush that ended behind the bucket seats on my 67 SS. OMG, no more noise like that, LOL.

 

[7Kings]

You could try and put the resonators back on, dampen some, but if U really wanna tone it down a bit, U gonna have to change out the muffler(s). Did U go true duals and 2 mufflers, or just single split into dual exhaust? Either way, U gonna have to tone down the muffler if U want less noise. Like I said, resonators may help, just not sure how much,. Like U, my days of big noises are done. Used to run dual Hush Thrush that ended behind the bucket seats on my 67 SS. OMG, no more noise like that, LOL.

I don't have resonators to put back on - it was previously a single-outlet setup and the new system is completely fabricated. It's a single muffler with dual outlets.

 

[turkeybird56]

Well, U could try and buy resonators, I am sure lots of PPL sell, or change out for a tone down on muffler. Only thing I can think of. We used to put temp outlet pipes on my hush thrush and jam them both with steel wool to quiet down for inspection, but once inspected, take off pipes and blow them out. That would not be an option for U, that was just teenager stuff to get around inspection stuff. Sorry, all I can think that would work. A lot of PPL use delete kits on resonators, somebody gotta be selling. Or back to change out muffler. I know, I AM no Help...

 

[7Kings]

LOL - I do appreciate your replies, and I'm thinking that the ultimate answer (and probably the cheapest) is just to have the muffler replaced with something else.

Now to figure out which to replace it with, I guess...

 

[IDSandman]

They won’t swap the muffler out? My local shop will swap a muffler until you are happy within a week of owning it.

 

[Wirerat]

I have a 2016 quad-cab with a 5.7 and just had a dual exhaust system fabricated by a local exhaust shop (was previously a single outlet). I really like the Flowmaster sound, but I thought I was asking for a Super-40 and the tech thought I was asking for an OG 40-series, which is what he installed. My fault for not double-checking before I signed off on the work, but live and learn... Not his fault and they did a really quality job on the fab and install. To his credit, he installed the muffler back near the rear axle, so it's not right under the cab.

So, the 40-series sounds really mean (sounds great) when you get on the throttle, but there's quite a bit of cabin noise when just driving around town - a little more than I'd like. When I'm on the Harley, the noise is part of the enjoyment, but the 40-series (and no rear resonators) is a little too aggressive for the truck to me.

That being said, I'm trying to figure out the best path forward. I was kicking around the idea of installing Dynamat sound-deadening under the carpet and across the rear cabin wall, which would just generally improve the overall interior sound levels, but I'm not sure how much that would help with exhaust sound. Alternatively, I can just have a different muffler installed and call it a day.

Thoughts? Recommendations? When I was a kid, I'd be stoked with the setup, but my 51 year old sensibilities prefer something a little milder.

View attachment 499710

That step bumper looks great. I wondered what those would look like on a actual truck.


Sorry for off topic.

 

[7Kings]

They won’t swap the muffler out? My local shop will swap a muffler until you are happy within a week of owning it.

Honestly, I didn't think to ask them. I just figured that it was my mistake, so I wasn't going to put it on them.

 

[7Kings]

That step bumper looks great. I wondered what those would look like on a actual truck.


Sorry for off topic.

Thanks - I wasn't sure about it until I got it and installed it. I'm really digging it.

 

[Wirerat]

Thanks - I wasn't sure about it until I got it and installed it. I'm really digging it.

You got some more pics of the truck? Turned out really good man.

 

[7Kings]

Thanks, man!

I only have one more of the back:


Here's the front with the decal I recently installed:

 

[KoboldTaco]

My experience with Dynamat is that it absolutely helps to cut down on interior deadening, for Audio as the main benefit. I measured with a previous noisy 2017 Prius at 74db at 70MPH and it dropped it to 68db. BUT, I TORE DOWN EVERYTHING and put the Dynamat directly on the frame, doors, inside skin, and everywhere I could find exposed metal And removed the entire floor carpeting and padding, added the mat then reinstalled. I was glad to do it but I don't think you will see the benefit as drastically as fixing the exhaust.

For those who love their audio, Kilmat or Dynamat...whatever you use will make a difference. When you close the doors it feels like you are in a sound studio.

I used an amazon knockoff and it was just as damn good as dynamat at a 1/3 of the price called Kilmat, 80mil.

 

[7Kings]

My experience with Dynamat is that it absolutely helps to cut down on interior deadening, for Audio as the main benefit. I measured with a previous noisy 2017 Prius at 74db at 70MPH and it dropped it to 68db. BUT, I TORE DOWN EVERYTHING and put the Dynamat directly on the frame, doors, inside skin, and everywhere I could find exposed metal And removed the entire floor carpeting and padding, added the mat then reinstalled. I was glad to do it but I don't think you will see the benefit as drastically as fixing the exhaust.

For those who love their audio, Kilmat or Dynamat...whatever you use will make a difference. When you close the doors it feels like you are in a sound studio.

I used an amazon knockoff and it was just as damn good as dynamat at a 1/3 of the price called Kilmat, 80mil.

I've heard good things about Kilmat.

 

[IDSandman]

I Kilmatted my cab for my audio build. Didn’t go as crazy Ktaco but did get pretty extensive. Huge difference.

 

[hunterdan]

Black widow venom 250 in place of the flowmaster. Great sound, zero drone.

 

[turkeybird56]

Thanks - I wasn't sure about it until I got it and installed it. I'm really digging it.

Reminds me of a GM step bumper, kinda see them on Silverado's, LOL.