Dodge Cummins Diesel Forum banner
  • Hey everyone! Enter your ride HERE to be a part of September's Cummins of the Month Challenge!

which muffler will be most quiet?

  • Flo Pro #8990 Baffled

    Votes: 0 0.0%
  • MBRP #1004 Quiet Tone

    Votes: 0 0.0%
1 - 20 of 21 Posts

·
Registered
Joined
·
273 Posts
Discussion Starter · #1 ·
(just moving the discussion here, sorry for the duplicate thread)

Hey all, looking to quiet my truck as much as possible. It's 2011 6.7 with some free-flowing exhaust modifications and tuning.
Currently 4" turbo back into a 30" FTE resonator. The FTE helped, but it was no miracle worker. It still drones quite a bit while towing, and is quite loud in the back seat for the kids (my wife can confirm)!

I have a MagnaFlow 60111 high flow CAT that is going to welded directly off the DP, moving the FTE back a bit. While we're under there messing around, i want to add a proper muffler since i have the space behind the FTE and before the axle rise.

I have narrowed my choices to the FloPro 8990 baffled, and the MBRP 1004 quiet tone. I like the smaller size of the MBRP, but if the larger FloPro will be noticeably more quiet i'll go that route.

As i understand, both are open chambers without packing. The FloPro is internally baffled, and MBRP is likely a hollow cannister with louvers that 'catch' the exhaust as it passes through the middle.

Thoughts, or any other recommendations?

The truck will never be a dyno-queen or track-star, so ultimate flow for ultimate power is not necessary. It is a daily driver that tows the family RV, so keeping it toned-down and as stealth as possible is the goal now.

TIA!
-jason
 
  • Like
Reactions: Djfan

·
Registered
Joined
·
76 Posts
I just recently put a Flo pro 6196 on my truck and it toned it down a good bit. However, that muffler is for a 5" exhaust. If you're looking for quiet then I think I've seen the Donaldson 51" thrown around a good bit here on the forum.
 

·
Registered
Joined
·
4,809 Posts
Donaldson for quiet.
 

·
Registered
Joined
·
273 Posts
Discussion Starter · #5 ·
Donaldson for quiet.
I just recently put a Flo pro 6196 on my truck and it toned it down a good bit. However, that muffler is for a 5" exhaust. If you're looking for quiet then I think I've seen the Donaldson 51" thrown around a good bit here on the forum.
I had the Donaldson 51" on my 2nd gen with good results.
No room for that sucker on this truck.
I have about 36" left to get a muffler in there.

Sent from my SM-G960W using Tapatalk
 

·
Registered
Joined
·
1,926 Posts
My 12 is setup like yours with 4" and I think the 12 is the only year with the tiny muffler just ahead of the axle, but I'm not sure. I never had drone with the vgt nor with the sxe 363. I took the rear muffler out and put in a diamond eye 51" big dog... Open chambers, no packing. I thought it would sound the way I wanted but it was way too loud, including at the rear of the truck. I packed the chambers with fiberglass and that deepened the tone but it was still too loud especially at the rear and I couldn't open the rear slider and stay sane for very long, towing. I packed the tiny rear muffler with FG and put it back in, along with the big dog, and it's OK with the rear slider open now, even towing. Running empty has an awesome deep pleasant tone!
Yours is the first one I've heard of that still has drone with a resonator.
 
  • Like
Reactions: Doj Dewd
Joined
·
3,499 Posts
Man, that catalytic converter is pricey!

Not sure if comparing my 5.9L with twins to your 6.7L is valid but I'm also RV towing a lot and did everything to my exhaust to keep it quiet, drone free and free flowing several years ago.

The cat will reduce the drone significantly and really clean up the diesel smell.
I noticed zero performance, EGT and fuel mileage differences when I re-installed my cat.
But, in my experience, the cat with a small muffler/resonator still won't be drone free and quiet enough while towing.

I prefer the SS MBRP to the aluminized FloPro but that MBRP is too small. I recommend to stuff in the largest diameter free flowing muffler that will fit.
8+ inches in diameter and as long as will fit.
Does Donaldson make some shorter mufflers?

Would it even be cheaper and easier to dump the FTE and just put in the largest Donaldson that will fit behind the cat?
If you didn't already have the FTE, a cat with the largest Donaldson would be my recommendation.

I have the factory cat, and 2 SS 8" diameter mufflers both about 24" long. Essentially 1 big Donaldson equivalent.
Quiet (deep), very quiet when not towing. Minimal drone and fairly quiet while towing up the Rogers Pass.
 

·
Registered
Joined
·
273 Posts
Discussion Starter · #8 ·
My 12 is setup like yours with 4" and I think the 12 is the only year with the tiny muffler just ahead of the axle, but I'm not sure. I never had drone with the vgt nor with the sxe 363. I took the rear muffler out and put in a diamond eye 51" big dog... Open chambers, no packing. I thought it would sound the way I wanted but it was way too loud, including at the rear of the truck. I packed the chambers with fiberglass and that deepened the tone but it was still too loud especially at the rear and I couldn't open the rear slider and stay sane for very long, towing. I packed the tiny rear muffler with FG and put it back in, along with the big dog, and it's OK with the rear slider open now, even towing. Running empty has an awesome deep pleasant tone!
Yours is the first one I've heard of that still has drone with a resonator.
don't get me wrong . . . the drone was significantly LESSENED . . . but the noise level is still pretty high. the drone is only present when towing, mostly
 

·
Registered
Joined
·
273 Posts
Discussion Starter · #9 ·
Man, that catalytic converter is pricey!

Not sure if comparing my 5.9L with twins to your 6.7L is valid but I'm also RV towing a lot and did everything to my exhaust to keep it quiet, drone free and free flowing several years ago.

The cat will reduce the drone significantly and really clean up the diesel smell.
I noticed zero performance, EGT and fuel mileage differences when I re-installed my cat.
But, in my experience, the cat with a small muffler/resonator still won't be drone free and quiet enough while towing.

I prefer the SS MBRP to the aluminized FloPro but that MBRP is too small. I recommend to stuff in the largest diameter free flowing muffler that will fit.
8+ inches in diameter and as long as will fit.
Does Donaldson make some shorter mufflers?

Would it even be cheaper and easier to dump the FTE and just put in the largest Donaldson that will fit behind the cat?
If you didn't already have the FTE, a cat with the largest Donaldson would be my recommendation.

I have the factory cat, and 2 SS 8" diameter mufflers both about 24" long. Essentially 1 big Donaldson equivalent.
Quiet (deep), very quiet when not towing. Minimal drone and fairly quiet while towing up the Rogers Pass.

hey Joe!

yes, it's a pricey little CATconverter . . . so i hope it performs well for my application! i did a price match during a sale last month to help lessen the blow . . . it still stung a little though!

why do you prefer the SS MBRP?
yes, the MBRP is small . . . so i was actually leaning toward the FloPro (8" x 30" chamber). and the FloPro is cheaper . . . i chatted with FloPro techs on the phone. They suggested the 8990 as it is still free flowing, and their largest muffler. It is open in the middle to baffled chambers, and a ball can be dropped straight through it.

i'd like to keep the FTE as it did help significantly with the drone compared to running a Nelson resonator (small) and muffler (huge) combo. i had the nelson products on, then took them off and replaced with only the FTE. Drone was WAY less, but the noise increased.

do you have a good source locally for Donaldson muffler sin the Calgary area? (or reasonable website)?
 
Joined
·
3,499 Posts
Hey Jason... So MBRP 304 SS is nice because it doesn't rust. :)

The aluminized steel exhaust components rust quickly in the Calgary winter with all the harsh chemicals they use on the roads these days.
They won't rust thru but they look lousy in 1 winter. Paint won't really help...

I've installed 2 Donaldson's in other trucks. 1 came from Tractor Trailer Supply on 52st SE.
I'm not sure if they're still there. We gave them the p/n and they ordered it up. Not cheap!

Last Donaldson was from amazon.ca. Not cheap but it arrived in a week.

Ideally, once you have your exhaust exactly how you want it, ceramic coating it in sections will make it look beautiful and last forever!
However, pricey and a 2-3 week turn around at Top Gun coatings in the NE.

I need to do a Montana run but no can do for now...
 
  • Like
Reactions: Doj Dewd

·
Registered
Joined
·
273 Posts
Discussion Starter · #11 ·
Hey Jason... So MBRP 304 SS is nice because it doesn't rust. :)

The aluminized steel exhaust components rust quickly in the Calgary winter with all the harsh chemicals they use on the roads these days.
They won't rust thru but they look lousy in 1 winter. Paint won't really help...

I've installed 2 Donaldson's in other trucks. 1 came from Tractor Trailer Supply on 52st SE.
I'm not sure if they're still there. We gave them the p/n and they ordered it up. Not cheap!

Last Donaldson was from amazon.ca. Not cheap but it arrived in a week.

Ideally, once you have your exhaust exactly how you want it, ceramic coating it in sections will make it look beautiful and last forever!
However, pricey and a 2-3 week turn around at Top Gun coatings in the NE.

I need to do a Montana run but no can do for now...
Ah, ok, you're liking SS mostly for appearance/longevity and inevitable rusting down the road. I was wondering if you noticed better performance with the heavier gauge steel...

My aluminized has held up very well for all the years it's been on there. Granted, I highway commute mostly, which doesn't see as much salt as city roadways. But still, the truck and all components underneath are still susceptible to all the harsh elements Winter throws at it! I do use all SS clamping hardware.

I remember getting a big Donaldson for my 2nd gen truck. It did work well. I did look at a Donaldson a couple years back, but they were really pricey and harder to find locally than they used to be. Montana runs haven't been as appealing as they were many years ago as our dollar was poor. Dollar is much better now... Just need to sort out what happens next with borders/COVID

I'm not terribly concerned about rusting. I can live with the surface rust. I'm guessing I'll be doing a 2nd gen swap before the exhaust components rust through... So I'll just revisit the exhaust system whenever that day comes! (although re-using the pricey CAT would be ideal if it performs well)

The price on the Flo Pro 8990 is good, and it's a great fit based on my measurements under the truck for fitting with clamps. Worst case, it can be welded in for a better fit if needed. It has a larger interior volume than MBRP 1004, and it is cheaper...in stock with free shipping from BCdiesel also...

If I need components welded in...
Who do you like in the Calgary area??

Sent from my SM-G960W using Tapatalk
 
Joined
·
3,499 Posts
I think the larger Flopro muffler is a good choice for you based on all the advantages.

A quiet free flowing common rail Cummins exhaust is great.
I'm one of the few that think a common rail Cummins sounds terrible with a straight pipe.
Sounds nothing like a good running 12V.
Sounds nothing like my Fox 5.0L Mustang with full length headers, H-pipe and dual 2 1/2 mandrel bent system!
My 5.9L CR was straight piped for about a month. It was ridiculous IMO...

I'm not a good enough welder to do exhaust systems. :)
All my exhaust work has been done at Calgary Muffler at Macleod and 58ave South for years.
Small independent shop that does tons of custom stuff and they let you in the shop to let them know exactly what you want and check it out before they drop the vehicle.
They even have an outdoor pit for RV work. I had them weld suspension hanger reinforcements on our 5th wheel.

Like any exhaust system work, hold a rag to the tailpipe to check for leaks while the engine is idling.
 
  • Like
Reactions: Doj Dewd

·
Registered
Joined
·
273 Posts
Discussion Starter · #13 ·
I think the larger Flopro muffler is a good choice for you based on all the advantages.

A quiet free flowing common rail Cummins exhaust is great.
I'm one of the few that think a common rail Cummins sounds terrible with a straight pipe.
Sounds nothing like a good running 12V.
Sounds nothing like my Fox 5.0L Mustang with full length headers, H-pipe and dual 2 1/2 mandrel bent system!
My 5.9L CR was straight piped for about a month. It was ridiculous IMO...

I'm not a good enough welder to do exhaust systems. :)
All my exhaust work has been done at Calgary Muffler at Macleod and 58ave South for years.
Small independent shop that does tons of custom stuff and they let you in the shop to let them know exactly what you want and check it out before they drop the vehicle.
They even have an outdoor pit for RV work. I had them weld suspension hanger reinforcements on our 5th wheel.

Like any exhaust system work, hold a rag to the tailpipe to check for leaks while the engine is idling.
I'm not a fan of the common rail straight piped trucks either. 12v and 24v sound great, but not so much on the CR....especially with the VGT turbo hiss...

Calgary Muffler is exactly where I was gonna go unless some local folks recommended anywhere different...

Good tip about hold a rag to the tailpipe...
I'll be sure to try it out for some leak checking.

Thanks Joe!

Sent from my SM-G960W using Tapatalk
 
  • Like
Reactions: StealthDiesel

·
Registered
Joined
·
273 Posts
Discussion Starter · #14 ·
I ordered the FloPro 8990.

I will report back here after i have everything installed for anyone looking for results!

Sent from my SM-G960W using Tapatalk
 

·
Registered
Joined
·
892 Posts
So you'll be pairing the 8990 with the 30" FTE in conjunction? This should yield a great result -

If you want stock like quiet there is a guy who fitted the 30" FTE with the 51" Donaldson - but it sounds stock quiet

Personally I am going with the Flo Pro 4" Muffler system (has the fiberglass packed 7195 muffler which is a 23" body), and I am adding the 30" FTE to that to keep it quiet in cabin - this should be best of both worlds for me - they make a "maxquiet " muffler setup as well, part M12722 - But I think I should be good with both of these, yes it may be louder than stock outside but should be good for my uses as I am 99% a highway unloaded beach cruiser with a napping 2 year old and puppy in the back
 

·
Registered
Joined
·
273 Posts
Discussion Starter · #16 ·
So you'll be pairing the 8990 with the 30" FTE in conjunction? This should yield a great result -

If you want stock like quiet there is a guy who fitted the 30" FTE with the 51" Donaldson - but it sounds stock quiet

Personally I am going with the Flo Pro 4" Muffler system (has the fiberglass packed 7195 muffler which is a 23" body), and I am adding the 30" FTE to that to keep it quiet in cabin - this should be best of both worlds for me - they make a "maxquiet " muffler setup as well, part M12722 - But I think I should be good with both of these, yes it may be louder than stock outside but should be good for my uses as I am 99% a highway unloaded beach cruiser with a napping 2 year old and puppy in the back
Yes, I will be combining the 30"FTE with the FloPro 8990.
Not only that, but will be adding the Magnaflow 60111 CATconverter right off the DP.

If I wasn't adding the CAT... Then I'd likely have room for the 30"FTE with 51" Donaldson.

I want the CAT to help clean up some of the raw diesel exhaust smell. The truck needs to idle through school pickup and drop off lines sometimes... I can't idle through there as is with the noise and smell... I'd feel awful doing that.

So, while I'm at it under there with the CAT...I figured I might as well try and get it as quiet as possible, hence the addition of the FloPro 8990 as the largest muffler I'll have room for.

Can you provide more info on the Maxquiet M12722 ?
I can't find any info on that part number...
Is it a Donaldson, or FloPro product?


Sent from my SM-G960W using Tapatalk
 

·
Registered
Joined
·
892 Posts
Sure thing so when I was researching FloPro's diesel mufflers they have a fiberglass packed straight through, a perforated baffle design, and the Max design which is their quietest they told me, in that order, all things being equal (muffler size)

FLO~PRO - Diesel Mufflers - Here is link - Twister is used as far forward as possible to kill interior db's/drone only -

Looks like the 8990 is the 'baffle design' which is quieter than the fiberglass packed perforated core I believe - the Max is M12722 only available in stainless

If you have a question on selecting a muffler they are very helpful by email ([email protected]) if you want to double check which is quieter but like I said you should have a great result

Please do update me on the 30" FTE with whichever muffler you go with, my impression is that it will still sound like a great truck outside, stock like in cabin with windows up on highway (which is what I want since my little man sleeps on trips), but nice subtle tone on throttle or when cruising with windows down
 

·
Registered
Joined
·
273 Posts
Discussion Starter · #18 ·
Sure thing so when I was researching FloPro's diesel mufflers they have a fiberglass packed straight through, a perforated baffle design, and the Max design which is their quietest they told me, in that order, all things being equal (muffler size)

FLO~PRO - Diesel Mufflers - Here is link - Twister is used as far forward as possible to kill interior db's/drone only -

Looks like the 8990 is the 'baffle design' which is quieter than the fiberglass packed perforated core I believe - the Max is M12722 only available in stainless

If you have a question on selecting a muffler they are very helpful by email ([email protected]) if you want to double check which is quieter but like I said you should have a great result

Please do update me on the 30" FTE with whichever muffler you go with, my impression is that it will still sound like a great truck outside, stock like in cabin with windows up on highway (which is what I want since my little man sleeps on trips), but nice subtle tone on throttle or when cruising with windows down
Interesting to hear about the advice you received from FloPro. I called and chatted with them a few months back, asking about their recommendation for the most quiet muffler. Without hesitation, the tech suggested #8990. He suggested the baffled were more quiet than their fiberglass packed such as #6195. There was non mention of the MX #M12722.

I'll try and get them on the phone again tomorrow to confirm. I think my #8990 is backordered anyway, so if I need to make a change I likely can.

Stay tuned . . .
 

·
Registered
Joined
·
892 Posts
Hey man - so I am ahead of you and correct my previous post
I talked to Flo Pro yesterday

“max” M12722 muffler and the 7195 muffler are the exact same part number, he said the fiberglass units just have a different part number when included in kits so he said get whichever you get a better price on

he said the baffle style is a bit quieter if you want aluminized (I don’t believe they come in stainless) - this is part 6192 and you are looking at the larger sized version of it (8990) - I specifically asked about the muffler included in kits and he said if they are the same size the baffle style is quieter

he said the 8990 series is absolutely the quietest muffler they make as long as you can accomodate the size

so if you want quieter than the standard muffler in the exhaust kits which is a 23” body fiberglass packed perforated core unit, the 8990 series will work best

however he said the 8990 series unfortunately is the one they are having extreme supply chain issues on so you may not be able to find it for a while
 

·
Registered
Joined
·
273 Posts
Discussion Starter · #20 ·
Hey man - so I am ahead of you and correct my previous post
I talked to Flo Pro yesterday

“max” M12722 muffler and the 7195 muffler are the exact same part number, he said the fiberglass units just have a different part number when included in kits so he said get whichever you get a better price on

he said the baffle style is a bit quieter if you want aluminized (I don’t believe they come in stainless) - this is part 6192 and you are looking at the larger sized version of it (8990) - I specifically asked about the muffler included in kits and he said if they are the same size the baffle style is quieter

he said the 8990 series is absolutely the quietest muffler they make as long as you can accomodate the size

so if you want quieter than the standard muffler in the exhaust kits which is a 23” body fiberglass packed perforated core unit, the 8990 series will work best

however he said the 8990 series unfortunately is the one they are having extreme supply chain issues on so you may not be able to find it for a while
Oh, awesome info.
Thanks for that, it saved me a phone call!

Glad to hear it confirms the baffle style is most quiet, and that larger is quieter. I have just enough room for the 8990.

I'll call the vendor I already ordered from. The order is still 'processing' so I would imagine it's backordered as you alluded...


Sent from my SM-G960W using Tapatalk
 
1 - 20 of 21 Posts
Top