PARTIALLY CORRECT, - Monst. Your sentence should have read "turbo charged motors dont need ADDITIONAL back pressure ( the turbo-charger and its housing & related parts provides plenty of back-pressure).

 

Sound wise I don't think it is that much louder, but the normal driving the drone is just annoying. Not loud just annoying. I do like the sound when I get on it.

 

True but the discussion is about removing the muffler. I was referring to your statement, "This was not true in the old days - plenty of articles in the SAE tech. journal about the necessity of SOME back-pressure for max. efficiency."
And "backpressure" is a misnomer, although like wheels being called rims, is acceptable common vernacular.

After the turbo, no "backpressure" is best.

 

I am not bored enough to look up any laws... The reason no muffler is req'd after turbo, is turbo greatly reduces exhaust noise. Legality? Nobody here has sugested removing any emmisions equipment - no cat in this exhaust system.

Like the others said, less backpressure after turbo is a good thing - albeit counter-intuitive to old skool gasser tech. There's ALOT of new things to learn when ya get into modern turbo diesels!

That brings us to the 'modern' computer control. That is the best part! It automatically adjusts for the improved conditions!! That is why stock trucks often see a few more psi of boost and at lower rpm's.

We totally agree about the headlights - that is NOT a good analogy. I am confused about your stance. At first you are appalled gov't doesn't regulate my vehicle more strickly - apparently to the point they have the power to TAKE IT FROM ME!! But later you recognize that common sense and manners will keep me from ever annoying the likes of you...

My truck with a stock exhaust, sans muffler - is only louder than stock under conditions rarely seen in an urban environment. Even with single-shot injectors, it is still much quieter than any 12v Dodge and is WAY quieter than the garbage truck! I live in campgrounds most of the year and since I leave very early for work in the AM, I am very conscience of how much noise I make. I admit, the exhaust sounds 'different', mostly more turbo whistle, but it produces similar Db's.

Now that we've taken a tangent way , lets see if the OP has learned what he was after! (too much 'drone' in a straight-piped X )

 

what about those that have gone with the 4" exhaust and no muffler? still the same drone?
4" drone compared to stock with muffler delete?

 

I think I'm just used to it. My 04 Z71 with a flowmaster 40 series droned much worse through the stock pipes.

FWIW, my wife has decided she hates the exhaust. That should provide funds in the near future for a turbo back system.

 

My '99 F250 was straight piped and sounded great. My wife's '01 Excursion was muffler-less from day one and she loves it. I'm tempted to straight pipe my F600 6.6 but still a little scared. Whatever you do, don't cut the muffler off a '92 F350 with a 7.3 NA!!! I can't wait to get a muffler back on that thing!

 

I have an 04 6.0 and I removed the muffler and went straight pipe for about 1 year. I took a couple of trips towing my hauler and it was terrible as far as that annoying drone!! If I didn't tow I would have the straight pipe, but for me I put a Walker BTM muffler back in! Ahhh much nicer while towing!!

 

Its not a federal violation taht I know of. Local ordinance violation and a small fine and fix it ticket. You bring in a BS receipt from a local muffler shop and it will most likely be thrown out.

 

You can cut out muffler.The s bend on the back un bolt at the clamp ,grind off the locator pin and turn pipe 180 tighten clamp. Then you can use straight pipe.I picked up a little mpg's.

 

Could you elaborate on this a little more, if you are still around? I am trying to do something similar and need some advice.

 

OMG !!!!

OLD DEAD THREAD alert !!!!
Agree - most municipalities have a sound ordinance they COULD ticket you on for mufflers... but in the country around here it's worse....

They have guns for the people that wake them up in the middle of the night


the federal laws relate to the emission controls.... now have heard of some that try to include the muffler in emission controls, but that is incorrect....