when i hacked my muffler out i put in a walker BTM (big truck muffler) i can't remember the part number but it was really cheap...all you did was cut both ends off and rotate that pipe like the others were talking about, clamp the new muffler in and go...sounds a lot better until you want a bigger exhaust or stacks

 

That's the one I was thinking of, Greg. Thanks!

 

Walker Big Truck Muffler

here's one from black cloud...i bet you could find it cheaper if you poke around. if you are that concerned with running straight piped then this is one of the best routes to go...after a few months with the walker i went to a 5" mbrp with muffler, then straight piped that, then went to 7" stacks...all depends what you are going for...i just want people to hear me coming

 

I am mainly looking for lower EGT's....which I know I will need with the Tuner chip.

Thanks for all the info guys. I think I will end up doing a cut and straight pipe this weekend. I want it ready for when the chip arrives.

 

When I cut the muffler out of mine I used a piece of flex pipe and stainless band clamps. That way I didn't have to line up the two ends of the pipes. It worked for over a year until I put on a 4'' exhaust.
As far as lowering you EGT's, the muffler delete is a great start. I hauled a lot of hay with mine and grossed about 23k at the scales, and pulling several 6% grades over 160 miles the exhaust temp never went over 1100*

 

i am thinking of purchasing a psd (coming from a gasser) and want to do this mod. however would this affect back pressure or anything? what are the downsides to this mod? i would just cut old exhaust off and put a straight pipe section in.

 

You'll love the diesel...

And yes, it affects back pressure! That's the idea -- back pressure *after* the turbo is bad. The turbo provides all the back pressure the engine needs and more. A lot of us go with bigger turbo exhaust housings to reduce it further in fact.

 

i see. so am i going to throw any codes or dash light by doing this or no?

 

I like the idea of removing the skin of the stock muffler adding a straight pipe then putting the skin back on. very sneaky, i like that.

 

Nope -- no codes. It's a good, cheap mod. I went straight for the 4" turbo-back mandrel bent though. With my larger exhaust housing and soon to be 6.0 IC, it'll be tough to get EGTs past 1300 unloaded.

 

I don't know, Joe. There seems to be a little disagreement with that in the exhaust world. When i've talked with Pinnacle Exhuast, who ahs been engineering racing exhaust systems for quite a long time, they don't even provide a complete 4" downpipe for even their 5-inch exhaust system... unless you're running over 500 hp. What they DO provide is a downpipe that starts out at the stock size and then transitions up to 4" before getting to the end of the downpipe.

Their explanation is that their testing and analysis has shown that you actually still need the higher velocity at that point before opening up the system because if you open it up too early in the exhaust flow path, you end up creating a backpressure pocket as the gasses cool down and get denser just a little further down the pipe. Basically, their just syaing that the transition to lower velocities and lower back pressure needs to be staged more gradually as opposed to simply opening up the system at a single point right out of the turbo outlet.

I found their explanation interesting, to say the least, and it seems they've done a lot of homework and "trial and error" to reach their conclusions, and though I cannot explain it with equations like Gene might be able to, I can see some real sense in the physics behind their conclusions.

 

Just noticed in your are in Church Hill, I am with you i like this idea and am going to be doing this soon myself, So i dont have to pay the "No Muffler" ticket i received from the THP. I'll be sure and post plenty of pics!

 

Here's my old thread on the subject... PSD Exhaust Systems... https://www.ford-trucks.com/forums/6...t-systems.html ...and I never got around to finishing it because as you mentioned trial and error experiments are probably the only way to optimize the exhaust configuration for either maximum HP or maximum efficiency (MPG) or some combination of these objectives.

To produce the maximum HP possible you need to achieve a "combined goal" of minimizing the back pressure at the exhaust valve ports during the exhaust strokes to reduce the pumping loss HP while simultaneously extracting as much heat ENERGY as possible from the exhaust flow to power the turbine to make a high boost so that you can combust more fuel to make more power stroke HP! The objective of exhaust mods aimed at maximizing HP isn't to reduce EGT but rather to combust as much fuel as possible at say an EGT of 1275 F!

 

I honestly think that by the time a guy has to worry about that, he's WWAAAAAYY up the HP food-chain. That said, a lot of the big pullers' exhaust goes out the turbo and straight up though the hood. You'd think that if anyone would need to exploit the last few ponies, it'd be them...

I'm not worried about here -- I have no plans on changing from my 4" turbo back to the rear fender...

 

Well on the subject of "vertical" stacks the equations are quite clear that they're "not" the way to go for maximizing HP because they work against the force of gravity but evidently they are required in competition events to try and get the smoke away from the crowd as much as is possible!