# When To Buy A New Exhaust System?



## CamperAndy (Aug 26, 2004)

Went camping this past weekend on the Selway river, had the campground almost all to ourselves and had a very good time. Even managed to float the river which was nice with it being this late in the season but I think the river road was a little too washboard as I think it was a contributing factor to what happens next.

A little background, my 2006 MegaCab just turned 84,000 miles when I got to the campground on the Selway river. I was happy with the performance but was still wished I had an exhaust brake for some of the long grades we have to go down as it is hard on the brakes. So I was actually talking to my DW about spending some money on a PacBracke or Banks exhaust brake. She was not real interested when she heard they were $1,200 to $1,500. So I told her the entire exhaust should be replaced soon and maybe next spring when Uncle Sam gives me back some of the money I loan him each year, I would get an exhaust system and an exhaust brake. Maybe $2,000 total and she was being nice and said okay. Not sure she was happy about it but I said me getting things for the truck is cheaper then a truck payment.

Drove home from camping I thought I heard a rattle in the back but just chalked it up to some poorly loaded item in the bed of the truck. I get home and start to unload the Rubbermaid buckets that I load all our junk in and the first one will not move. After giving it a really good tug it comes away and I see the bottom is melted and the bed liner is bubbled and cracked. The rubber float tube in the bottom of the bucket was also melted. The black areas on the bed liner are where the rubbermaid bucket had melted to the bed.



















Well that does not happen on its own so I climb under the truck and below is what I see.










The location in the above photo is where the resonator is connected to the tail pipe where it goes over the rear axle. When the tail pipe broke the heat was pointed directly at the bed of the truck. I still need to drop the spare tire and check to see if it is damaged. There was a possible serious issue since I carry a plastic jug of Diesel fuel for the truck when I go go camping and I also had my generator and a some spare gasoline for it in the bed. Luckily none of those items were located in the bed next to where the pipe failed. I think I drove for about 300 miles with the broken pipe.

Well now I will be getting the new exhaust system a little earlier then expected. Will still have to wait for the exhaust brake. So about 1/3 of the cost now and the other 2/3's next spring. Then I will also have to look into getting the bed liner replaced, that expense is what bothers me the most, just have to keep telling myself that it is cheaper than a new truck and having a payment!!


----------



## TwoElkhounds (Mar 11, 2007)

Wow! Thanks for the heads up. I have the same truck and will definitely crawl up under the truck to check it out. I actually have my Honda generators and my extended run fuel tank in the bed of my truck in the area where you had the problem. So you bet I will check this out.

Just curious, do you drive your truck in the winter and do they use salt or some other de-icer on the roads in the winter?

DAN


----------



## Leedek (Nov 28, 2010)

Whew.... that was a big bullet missed!







I am glad to hear that your whole rig didn't explode. I know that you must have had a moment when you thought of the "What ifs..."









Your experience encourages me to go look under my truck and be sure all is well. Thanks for sharing.


----------



## CamperAndy (Aug 26, 2004)

TwoElkhounds said:


> Just curious, do you drive your truck in the winter and do they use salt or some other de-icer on the roads in the winter?
> 
> DAN


I do drive in the winter but not a lot and the roads around here do not get salted. Mostly just sand and near intersections they use an anti freeze but it is (appears to be) non corrosive. We have very few cars that have rust damage from salt. One thing that could be a contributor is I use water injection when towing. Until I get it apart I will not know if the rust was inside out or outside in. If you look at the picture of the bottom of the truck there is no rust to speak of.


----------



## TwoElkhounds (Mar 11, 2007)

CamperAndy said:


> Just curious, do you drive your truck in the winter and do they use salt or some other de-icer on the roads in the winter?
> 
> DAN


I do drive in the winter but not a lot and the roads around here do not get salted. Mostly just sand and near intersections they use an anti freeze but it is (appears to be) non corrosive. We have very few cars that have rust damage from salt. One thing that could be a contributor is I use water injection when towing. Until I get it apart I will not know if the rust was inside out or outside in. If you look at the picture of the bottom of the truck there is no rust to speak of.
[/quote]

Yes, your truck looks clean. I only ask because they dump tons of salt on the road here and it eats cars, especially brake rotors and exhaust systems. Just thought that might have been a contributing factor.

Hopefully the heat did not damage the paint on the bottom of the truck bed too badly. Would suck to have to also get that repainted on top of everything else.

DAN


----------



## CamperAndy (Aug 26, 2004)

TwoElkhounds said:


> Hopefully the heat did not damage the paint on the bottom of the truck bed too badly. Would suck to have to also get that repainted on top of everything else.
> 
> DAN


That would take a can of BBQ grill flat black and would be good to go. I am still worried about the effects on the bed liner. Patching it is not really an option so having to strip it out so it can be resprayed is not something I am looking forward to.


----------



## W5CI (Apr 21, 2009)

That must be a dodge, as all Gm trucks I have seen have stainless steel exhaust


----------



## CamperAndy (Aug 26, 2004)

danny285 said:


> That must be a dodge, as all Gm trucks I have seen have stainless steel exhaust


This is not a my truck is better thread.


----------



## CamperAndy (Aug 26, 2004)

robertized said:


> It is hard to tell from the pictures just how much clearance there is between the exhaust pipe and the truck bed above. But maybe installing a piece of sheet metal on to the bed supports as a heat shield above this section of exhaust pipe would help to keep from heating up cargo stored in the bed normaly.


They only have heat shields above the catalytic converter. By the time it gets back to the tailpipe the radiant heat is low enough it it not an issue. On the other hand you break a pipe and point it at the bed well that is a horse of a different color. I could install a heat shield but I doubt it would ever be needed again once I install the new system. The new system has a single pipe from the muffler to the outlet and no joint or weld to fail above the axle.


----------



## Bob in Virginia (Jul 15, 2010)

Andy, when I replaced my exhaust 2 years ago, I put on an MBRP 4" exhaust. I don't recall who I bought it from, but they are available on-line from lots of places. I was able to install it myself, the fit and finish were outstanding and it is still doing well. The 4" helps the diesel breath a little better pulling the OB, especially up the mountain roads. MBRP has both stainless and aluminized exhaust available. I went with the aluminized to save some $$. Looks like you dodged a bullet with this one.


----------



## CamperAndy (Aug 26, 2004)

Bob in Virginia said:


> Andy, when I replaced my exhaust 2 years ago, I put on an MBRP 4" exhaust. I don't recall who I bought it from, but they are available on-line from lots of places. I was able to install it myself, the fit and finish were outstanding and it is still doing well. The 4" helps the diesel breath a little better pulling the OB, especially up the mountain roads. MBRP has both stainless and aluminized exhaust available. I went with the aluminized to save some $$. Looks like you dodged a bullet with this one.


Well you must be at least partially clairvoyant, yesterday I ordered a 4" MBRP turbo back system, in 409 Stainless steel. The Dodges come with 4" systems from the factory but the bends and stock muffler create some restriction. So the new system should flow better. I just don't want it to be much louder. I thought about going up to a 5" system but everyone says they have more issues with mid range drone which would be a major pain when towing, so I am sticking with a 4" system.

I will follow up with installation photos when I put the system on later this week.


----------



## Bob in Virginia (Jul 15, 2010)

I think you will be pleased with the 4", and the sounds from the muffler are really nice. Just make sure you put the muffler on going the right direction. My DW is even ok with it.


----------



## CamperAndy (Aug 26, 2004)

Bob in Virginia said:


> the sounds from the muffler are really nice. Just make sure you put the muffler on going the right direction.


That sounds like the voice of experience!


----------



## Bob in Virginia (Jul 15, 2010)

I just checked it multiple times to make sure it was right. Check twice, tighten once.


----------



## thefulminator (Aug 8, 2007)

Andy, I hope that you have learned something from this. The next time you want to make a mod to your truck or trailer, ask the wife about it six months before you think it really needs to be done.


----------



## SLO250RS (Mar 11, 2010)

Andy if I might suggest something,dont use the standard clamps that come with the kit purchase the band clamps instead they are few bucks more and wont crush the pipes to seal.If you ever have to dissasemble or adjust any of the pipes you will be glad you used the band clamps.JMHO


----------



## CamperAndy (Aug 26, 2004)

SLO250RS said:


> Andy if I might suggest something,dont use the standard clamps that come with the kit purchase the band clamps instead they are few bucks more and wont crush the pipes to seal.If you ever have to dissasemble or adjust any of the pipes you will be glad you used the band clamps.JMHO


Do you have a link to the camps in question?

The stock system had to be cut out. Even though I got the nuts off the factory "U" bolt clamps, there was no way any of it was going to come apart. So it was a sawzall to the rescue.


----------



## CamperAndy (Aug 26, 2004)

thefulminator said:


> Andy, I hope that you have learned something from this. The next time you want to make a mod to your truck or trailer, ask the wife about it six months before you think it really needs to be done.


Got to get a new crystal ball for that to work.


----------



## SLO250RS (Mar 11, 2010)

CamperAndy said:


> Andy if I might suggest something,dont use the standard clamps that come with the kit purchase the band clamps instead they are few bucks more and wont crush the pipes to seal.If you ever have to dissasemble or adjust any of the pipes you will be glad you used the band clamps.JMHO


Do you have a link to the camps in question?

The stock system had to be cut out. Even though I got the nuts off the factory "U" bolt clamps, there was no way any of it was going to come apart. So it was a sawzall to the rescue.
[/quote]

Here is Dynomax 4"dia.accuseal clamp part#36441 they are avalible thru Summit Racing,hope this helps.


----------



## scuba0331 (Dec 7, 2011)

SLO250RS said:


> Andy if I might suggest something,dont use the standard clamps that come with the kit purchase the band clamps instead they are few bucks more and wont crush the pipes to seal.If you ever have to dissasemble or adjust any of the pipes you will be glad you used the band clamps.JMHO


Do you have a link to the camps in question?

The stock system had to be cut out. Even though I got the nuts off the factory "U" bolt clamps, there was no way any of it was going to come apart. So it was a sawzall to the rescue.
[/quote]

Here is Dynomax 4"dia.accuseal clamp part#36441 they are avalible thru Summit Racing,hope this helps.
[/quote]

I used these clamps on my 74 Duster. http://www.summitracing.com/oh/parts/wlk-33272/overview/


----------



## rdvholtwood (Sep 18, 2008)

I just broke 80,000 on our Dodge Ram and probably should take a look underneath. Do diesel's run hotter than gas? I've never seen anything like that before. Didn't you hear when the exhaust separated? Just curious.


----------



## CamperAndy (Aug 26, 2004)

rdvholtwood said:


> I just broke 80,000 on our Dodge Ram and probably should take a look underneath. Do diesel's run hotter than gas? I've never seen anything like that before. Didn't you hear when the exhaust separated? Just curious.


The only thing that separated was the tail pipe, thus it was downstream of all the sound attenuation components . This would not have been an issue had it not been pointed at the truck bed over the axle. Diesel exhaust can run hotter but on disassembly and inspection the failure mode was external in origin. The exhaust is Aluminium coated steel and there were significant levels of corrosion present at all weld points within the system. This corrosion was to the base metal and only in the heat zone around welds indicating that the aluminum protective coating was compromised. Looks like they should have re treated the welded areas with flame sprayed aluminum powder to reestablish the protective coating. There was also I suspect a mechanical component to failure as there was some overhung and unsupported weight in the tail pipe. The only thing I heard was some banging in the bed and I just suspected it was a piece of firewood rolling around. Turns out it was the tail pipe bumping into the bottom of the truck bed.


----------



## CamperAndy (Aug 26, 2004)

SLO250RS said:


> I used these clamps on my 74 Duster. http://www.summitracing.com/oh/parts/wlk-33272/overview/


Yes those look like they would work but I wonder if it depends on the joint being a butt or slip joint in the pipe. If the kit comes with standard "U" bolt clamps I will see about upgrading to the type you gents reference.


----------



## clarkely (Sep 15, 2008)

i think you will be happy with te 4" ss - i have AFE stainless 4"

they do use a less expensive stainless than if you find someone who does the better grade ss - i had found someone that would do mine - but it was a little over twice the cost and a three hour drive ..... figured the AFE went in so easy i could afford to do it twice and be ahead of the game.....

If you think water injection was a contributing factor .......... i guess it would lead me to take a good look at the down tube and make sure there are no other issues ......... however that bend looks like a good accumulation area for moisture to accumulate and do its thing....

like others said glad you averted a disaster


----------



## CamperAndy (Aug 26, 2004)

clarkely said:


> i think you will be happy with te 4" ss - i have AFE stainless 4"
> 
> they do use a less expensive stainless than if you find someone who does the better grade ss - i had found someone that would do mine - but it was a little over twice the cost and a three hour drive ..... figured the AFE went in so easy i could afford to do it twice and be ahead of the game.....
> 
> ...


Well as I mentioned the old system is out and the damage was found to be from the outside in. There was no corrosion pitting at all on the inside of the pipes, it was all on the outside and on or adjacent to the factory welds.

I am doing a complete replacement, turbo to tailpipe tip. Should remove any future issues.

The new system should be here in a couple of hours, I will post pictures of the new installation.


----------



## Fanatical1 (Jan 9, 2006)

I'm not an exhaust expert by any means, but know a little about steel. Aluminized steel or Galvalume are many OEM selections for exhaust systems. These coatings are typically a 90% aluminum, 10% zinc blend applied over a cold rolled steel coil. When its welded the coating is destroyed during the welding process which I think your referencing with your comment about touching up the welds. There is no good way to economically touch up the welds that yields good corrosion results, so the welds are the first things to fail. Stainless however can we welded with good results using stainless rods.


----------



## SLO250RS (Mar 11, 2010)

CamperAndy said:


> I used these clamps on my 74 Duster. http://www.summitracing.com/oh/parts/wlk-33272/overview/


Yes those look like they would work but I wonder if it depends on the joint being a butt or slip joint in the pipe. If the kit comes with standard "U" bolt clamps I will see about upgrading to the type you gents reference.
[/quote]
I have used the dynomax/accuseal clamps only on slip fit connections without fail,I have purchased them for my banks exhaust to replace the clamps that came with it.The MBRP exhaust fit well just retorque every fastener after a heat cycle.


----------



## Collinsfam_WY (Nov 9, 2006)

Andy, how are you liking that 4" MBRP Turbo Back? That is what I run on my truck and I really like it. No drone when towing, great sound overall.

-CC


----------



## CamperAndy (Aug 26, 2004)

collinsfam_tx said:


> Andy, how are you liking that 4" MBRP Turbo Back? That is what I run on my truck and I really like it. No drone when towing, great sound overall.
> 
> -CC


Well the DW was not too impressed when I hit the first 7% grade!! Cruising at 45 to 65 on flat runs with the trailer and it was just fine with her but anytime I stepped on it, well lets just say I got to hear her opinion of it. After our first camping trip she said she would deal with it if she had to but would like me to research a quieter muffler. So now I am looking for a resonator or another muffler to add to the system. The straight through MBRP muffler does not seem to attenuate the sound all that much.

The leader at the moment are a muffler by Donaldson but I can not find a local dealer with one in stock. I am in no rush and will most likely wait until next spring to get it along with the exhaust brake I want.


----------



## clarkely (Sep 15, 2008)

CamperAndy said:


> Andy, how are you liking that 4" MBRP Turbo Back? That is what I run on my truck and I really like it. No drone when towing, great sound overall.
> 
> -CC


Well the DW was not too impressed when I hit the first 7% grade!! Cruising at 45 to 65 on flat runs with the trailer and it was just fine with her but anytime I stepped on it, well lets just say I got to hear her opinion of it. After our first camping trip she said she would deal with it if she had to but would like me to research a quieter muffler. So now I am looking for a resonator or another muffler to add to the system. The straight through MBRP muffler does not seem to attenuate the sound all that much.

The leader at the moment are a muffler by Donaldson but I can not find a local dealer with one in stock. I am in no rush and will most likely wait until next spring to get it along with the exhaust brake I want.
[/quote]

just turn the radio louder









My wife likes when our truck grunts







we are straight piped ..... i know there a lot of resonators available that help in dampening the sound ..... also if exhaust is down pointed to much or back pointed towards the trailer ...... sound bounce back can amplify it......

in our truck it seems to be louder in the drivers seat than anywhere else......


----------



## Collinsfam_WY (Nov 9, 2006)

Andy that is interesting. My 6.7 sounds pretty nice through it and it has a nice deep "thump" at idle. Not too loud and when climbing the engine sound is louder than the exhaust. Nobody has complained and believe me, I was worried about that when I first had that exhaust put on. Towing at 65mph, my 6.7 is turning something like 1600-1700rpm (3.73 gear, 6spd trans). What does your 5.9 turn at 65mph?

-CC


----------



## CamperAndy (Aug 26, 2004)

collinsfam_tx said:


> Andy that is interesting. My 6.7 sounds pretty nice through it and it has a nice deep "thump" at idle. Not too loud and when climbing the engine sound is louder than the exhaust. Nobody has complained and believe me, I was worried about that when I first had that exhaust put on. Towing at 65mph, my 6.7 is turning something like 1600-1700rpm (3.73 gear, 6spd trans). What does your 5.9 turn at 65mph?
> 
> -CC


The issues only seem to come into play when I get over 2000 RPM, Below that it seems okay to me. At 65 I am doing 1750ish in 4th gear. It is a single exit, side, behind the rear wheel. There were a few options and again this one was reported as the least noisy when towing. I had convinced my DW it was okay as we were tooling at at about 55 mph, towing with the exhaust side toward the river and had her open the window. She even said it sounded just a little louder but okay. Then we passed a concrete rail barrier between the road and the river and the reflection of the noise off the wall was amassing you should have seen the 180 my DW did. Closed the window and said that is what everyone else hears! So that is why I am on the hunt for a muffler.

Is your 6.7 system a 4 or 5"? I went with the 4 as it was reported as having less drone. Also did you do Turbo back, Cat back or DPF back? I did turbo back and I am sure that is a contributor.


----------



## Collinsfam_WY (Nov 9, 2006)

CamperAndy said:


> Andy that is interesting. My 6.7 sounds pretty nice through it and it has a nice deep "thump" at idle. Not too loud and when climbing the engine sound is louder than the exhaust. Nobody has complained and believe me, I was worried about that when I first had that exhaust put on. Towing at 65mph, my 6.7 is turning something like 1600-1700rpm (3.73 gear, 6spd trans). What does your 5.9 turn at 65mph?
> 
> -CC


The issues only seem to come into play when I get over 2000 RPM, Below that it seems okay to me. At 65 I am doing 1750ish in 4th gear. It is a single exit, side, behind the rear wheel. There were a few options and again this one was reported as the least noisy when towing. I had convinced my DW it was okay as we were tooling at at about 55 mph, towing with the exhaust side toward the river and had her open the window. She even said it sounded just a little louder but okay. Then we passed a concrete rail barrier between the road and the river and the reflection of the noise off the wall was amassing you should have seen the 180 my DW did. Closed the window and said that is what everyone else hears! So that is why I am on the hunt for a muffler.

Is your 6.7 system a 4 or 5"? I went with the 4 as it was reported as having less drone. Also did you do Turbo back, Cat back or DPF back? I did turbo back and I am sure that is a contributor.
[/quote]

My system is a 4" turbo back that only uses the small straight through muffler that came with it from MBRP. I think one thing that might also help is how much more smoothly it runs with the EFI Live. I didn't want it loud at all and was wondering if I would end up in the same situation you are in as my DW is sensitive about it. In fact, when I put on the S&B, I kept the old intake in case DW complained about hearing the turbo. So far, so good on that as well. You can tell it is louder though when passing under bridges with the windows down. Good luck with the muffler research. Let us know what you do. I am interested to hear what you chose and why.

Bit of a subject change, when you pull grades like that 7% you were referring to, what EGT's do you see? I just had to have my exhaust manifold pulled and milled as it warped enough to allow the stock gasket to be blown out in a small spot. Manifold bolts were all good. I have assumed that high EGT's while pulling passes either caused or contributed to it but I could be wrong and it might be just something that happens over time as the truck now has 90k. The most I typically see when pulling a pass at speed is 1200. I normally try to keep it under 1100. Probe is on the back of the manifold so actual temps are probably around 100 higher at the collector.

-CC


----------



## CamperAndy (Aug 26, 2004)

I also have an S&B intake and intake horn, Also an EDGE Juice with Attitude and a Cooling mist water/meth injection system. So lots of variables.

The EGT probe is placed in the collector to the front of the internal rib so it is monitoring 1, 2 and 3. On the 5.9 there is no easy way to get the probe to monitor all 6 cylinders.

Just rolling down the highway at 65 pulling the trailer I run 800 to 850. Pulling grades with the trailer, I drop a gear to get the RPM up to about 2400 and feather the pedal to maintain boost between 30 and 40 and that holds the EGT to less than 1300. The Water injection drops the EGT about 150 and that means I can get up the grade 5 mph faster and still keep it under 1300 if I want to. I have run up the same long grade with nothing (Stock program and no water) and I could see 1500 if I was not careful.

One thing you have on the 6.7 that I don't have that would affect the sound is the variable geometry turbo. This can relly affect the exhaust system.


----------



## SLO250RS (Mar 11, 2010)

Andy have you looked at the Magnaflow website?They have a good selection of mufflers that you can replace the small mbrp muffler with one that has more internal volume and the same flow characteristics.Hope this helps.


----------



## CamperAndy (Aug 26, 2004)

SLO250RS said:


> Andy have you looked at the Magnaflow website?They have a good selection of mufflers that you can replace the small mbrp muffler with one that has more internal volume and the same flow characteristics.Hope this helps.


I feel like I have looked at hundreds of web sites. One thing that I wish they had in the description was a statement of db attenuation or at least a cross section of the muffler to show what it looks like.

The only mufflers that show the db drop that I have found is the Donalson site. I have emailed MBRP to ask what the db drop is on their "Quite tone" muffler (M1004S) is but they have not responded back.

If anyone wants to see if they can chase down one, I am looking for a 409 stainless steel (maybe 304 ss one but those are expensive), 4" inlet and outlet centered. Length 30" up to 51". I would like to see the estimated db attenuation.


----------



## SLO250RS (Mar 11, 2010)

CamperAndy said:


> Andy have you looked at the Magnaflow website?They have a good selection of mufflers that you can replace the small mbrp muffler with one that has more internal volume and the same flow characteristics.Hope this helps.


I feel like I have looked at hundreds of web sites. One thing that I wish they had in the description was a statement of db attenuation or at least a cross section of the muffler to show what it looks like.

The only mufflers that show the db drop that I have found is the Donalson site. I have emailed MBRP to ask what the db drop is on their "Quite tone" muffler (M1004S) is but they have not responded back.

If anyone wants to see if they can chase down one, I am looking for a 409 stainless steel (maybe 304 ss one but those are expensive), 4" inlet and outlet centered. Length 30" up to 51". I would like to see the estimated db attenuation.
[/quote]
OK this is what I found Magnaflow 409ss 7" dia by 30" body length 36"overall 4" in and out centered Part# 12773 with that much internal volume that muffler will take the bark out of that 6 banger







hope this helps.


----------



## clarkely (Sep 15, 2008)

CamperAndy said:


> Andy have you looked at the Magnaflow website?They have a good selection of mufflers that you can replace the small mbrp muffler with one that has more internal volume and the same flow characteristics.Hope this helps.


I feel like I have looked at hundreds of web sites. One thing that I wish they had in the description was a statement of db attenuation or at least a cross section of the muffler to show what it looks like.

The only mufflers that show the db drop that I have found is the Donalson site. I have emailed MBRP to ask what the db drop is on their "Quite tone" muffler (M1004S) is but they have not responded back.

If anyone wants to see if they can chase down one, I am looking for a 409 stainless steel (maybe 304 ss one but those are expensive), 4" inlet and outlet centered. Length 30" up to 51". I would like to see the estimated db attenuation.
[/quote]

check around for a local guy - i know when i was looking i found a guy who would make one fro around 1,000.00 all 1 piece turbo back ...... my afe 4" was like 540.00 ....hindsight being 20/20 i think i would go custom better SS next time


----------



## CamperAndy (Aug 26, 2004)

Well here is the update. After much searching I could not find exactly what I was looking for so I compromised. Rather than replace the muffler that came with the new exhaust, I added a new slightly different muffler that was chambered but still a straight through design. I added a MBRP M1004S Universal Quiet Tone Muffler, 409 ss, 4" centered inlet and outlet and about 34" long. The results were very good. Dropped the db from 78 to 71 in the cab and outside the drop was more or less the same amount before and after, 6 to 8 db. I put the new one in front of the one that came with the system about 20 inches.

Now the real test will come in the spring when I tow but I think it will be acceptable.


----------

