I've got a 99 2500 24v 5spd ram. I was just wanting some of ya'll opinion. I've upgraded my stock exhaust. Bank's 4" power elbow, 4" down tube and 4" pipe all the way to the back. I had a flowmaster diesel muffler on the truck, but I always thought it was restricting the flow so I took it off. Now it almost seems like the truck is lacking of low end torque. First, is it best to run a diesel with or without a muffler? I've heard mixed opinions on the whole back pressure thing. Next, will i hurt the motor over time without running a muffler( little or no back pressure)?

 

I took mine off and I like it.. it is really loud under load though

 

I've been runnig the stock size pipes(3" ) for a while now without a cat or muffler,not at all loud,and no effects,no noticable power gain or loss. I.M.O. Unless your really putting Huge amounts of air in(big twin turbos,higher rpm capability) those big pipes are only changing the tone of your note . Muffler or not I dont think it makes a diff.,only to your neighbors. I've blown plenty of manifold gaskets in my day(on my old gasser) and when your engine sounds crappy at low rpm's it messes with your head and you think your down on power. open systems made a diff.on old carb. feed gasses,(used to have to increase jet sizes).When it comes to injection,I'm not sure it makes a diff. Turbos dont like backpressure,they like air velocity, out needs to be equal or greater than in,so you should be fine with your 4",muffler or not.

 

Dont confuse gasoline engines and diesel engines. The will react to intake and exhaust changes much differently than each other because diesel doesn't follow the required 14.7 to 1 air/fuel ratio requirements that gasoline does. If you change the intake or exhaust on a carbureted gas engine then you need to change the jets to accommodate the increase in air as well so the A/F stays as close to 14.7 to 1 as possible (depending on HP). Do the same on a fuel injected gas engine and the computer takes care of all the adjustments for you (to a point). However, diesel engines can run as lean as 40 to 1 or as rich as 2 to 1. Gasoline will run hotter when lean and cooler when rich but a diesel will do the opposite. Diesel engines will run hotter and hotter the richer the A/F ratio becomes. Kinda like a furnace.

Which leads me to your question. You noticed a loss in power with no muffler. That could simply mean that your exhaust is just to big and to open for your engines current HP output. Engines need hot exhaust pipes to keep the exhaust gages hot so that the gases stay light and fast. This way the gases free flow through the pipe, causing a scavenging affect as it actually pulls the rest of the exhaust along. But if you open the exhaust to much or get to large of an exhaust pipe then the engine may not make enough HP heat for the exhaust system. Then what happens is the exhaust gases cool to soon and become slow and dense causing turbulence as the hot light gases collide with the slow dense gases. This can cause HP and fuel mileage loss. If you do some research on this you'll find that racers will literally tune their engine to the exhaust. This is done by changing the size and length, especially right off the engine and where all the individual cylinder pipes come together.

As for back pressure, thats nothing forced induction engines need. Naturally aspirated engines utilize back pressure for various reasons involving intake and exhaust velocity. But thats a totally different topic.

But dont misunderstand what I'm talking about either because I'm not saying that hot EGT's are good. Thats something totally different. If you cant keep your EGT's from pegging the pyro then you need to reduce the intake temp. add more air, and/or reduce the retained exhaust systems heat. Thats where larger exhaust pipes and deleted mufflers come to play. As much as us diesel hot rodders love to turn up the boost, change the intake, and get massive exhaust systems on trucks that make little more or stock power.....knowing whats going on is half the fun.

 

I'm sick of the straight pipe and want to slap a Donaldson on there. I'm going deaf

 

^^^ This guy knows what's up!!!

Great advice!
Chris

 

Excellent Information, Being new to diesels,I just learned quite a bit. Love this forum

 

FTE Resonator was the best thing i got for my truck... I can even hear the radio on the highway now!!! its sweet lol

 

I got the muffler delete pipe from Geno's Garage, and at first I loved the sound. Over time though, it wears on you and I now want to replace that straight pipe with a straight through design muffler--doesn't really matter to me what brand or type.

 

Thanks for all the help and info guys!!

 

I called Rip Rook and he is going to sell me a 4" turbo back with 2 mufflers!!! Think I'm going to the extreme????

 

I was going to get another muffler to go along with my resonator but there isnt enough room. I think the fte resonator along with a 52" donaldson would be nicee.

 

I've got a 4" MBRP with no muffler.

I live in a retirement town and I see the old ladies covering their ears even when I'm going slow. The only time I get the 'drone' is towing up steep grades or WOT. Cruising at 70-80 I think it sounds fine. I did dynamat the interior which helped....and I only have 50% hearing in my right ear....(military took the other half)

Most kits come with a muffler....IMO give it a shot with it, and if you want it louder than get a delete pipe.

 

I'll share my experience with the drone..... Its terrible. It got to the point where I hated to tow because of the noise so after reading about why the drone happens, which is simply because the exhaust pipe acts just like a guitar string which vibrates at specific RPM levels, I experimented. I took a 5'-6' T-post and strapped it to the exhaust pipe with large hose clamps where the muffler and resonator were. This was to change the dynamics of the exhaust pipes mass. To my surprise the drone was reduced significantly. I haven't tried moving the T-post or adding more T-posts to see if it changes anything either. Even though I mounted the T-post to the top of the pipe and there's zero chance of seeing it, I can see where thats to cheesy for some so if you can weld something equivalent there if it makes you feel better. I just thought I'd let anyone know that there is hope to get ride of the drone without having to buy a muffler or new exhaust system.

 

I thought open pipes on a diesel didnt make a difference, b/c the turbo supplies the backpressure it needs? I know on gassers, and especially 2 strokers, that you will get optimum performance depending on exhaust setup.

As for the noise, it's up to you, and how much you can stand. I love the sound of my truck (5" turbo back to dual 7" turnout stacks). It's got a real nice deep growl, people always tell me it sounds like a semi, but at about 70 mph it howls so bad I usually end up speeding up or slowing down to get out of that RPM range.