In my area if you have a diesel its got a straight pipe

 

How a Ford Excursion without a muffler sounds inside the cab - YouTube

I heard some nasty vids with WWs, foil deletes and all kinds of things to make the whistle in the cab obnoxious. I saw this vid and I am encouraged.

 

slap a k&n cone filter under the hood- sounds like a airplane toilet flushing.

straight pipe exhaust- sounds like a garbage truck following you around.

was cool at first, now i just turn up my radio!

kurt

 

I have the Ford AIS and I couldn't be more pleased with that.

I have finally reached an executive decision:

1. AE to get baseline data before I go forward with anything else.
2. Muffler delete alone to compare data, performance, and sound.
3. 4" as needed, with the configuration I decide, based on my experience with the stock pipe and muffler delete.

Thanks to all who shared their experences/knowledge... I would have been in the tall weeds without you.

 

I've got just about the cheapest, simplest setup you could go with, and I wouldn't really recommend it exactly how I did it. I just took off the muffler and everything past it. So I'm just running with the stock downpipe and about 2-3 feet of stock pipe past that. It dumps out under the middle of my bed. This wasn't really something I put much thought into...I kept on banging my head on the exhaust when I was doing the in tank mods, got pissed, ended up pulling off the muffler and everything back, and ended up with this. It took me 15 minutes, and it made the truck REALLY loud, (fun I guess but it gets old), and I don't bang my head on an exhaust anymore when I'm under the truck.

No real noticeable mpg gains, maybe a little bit, but nothing worth mentioning. I've mentioned my mileage before...I'm not really driving in any way to measure realistic mpg's anyways. For my almost non-existent power mods, I really don't think full 4" is necessary, and I doubt it would do anything more for me other than sound more refined.

I will say, with my specific setup, turbo whistle is LOUD outside the cab, especially at idle and light throttle. I'd expect that to go away a little bit if I extended the exhaust back to a normal exit location. There's a lot of diesel rattle and clatter that comes out the exhaust too though the exhaust note is really surgey and choppy and harsh...it sounds like exactly what it is. A cheap, redneck modification. My neighbor hates it, she says I wake her up every morning when I leave. I'm cool with it, it's about all I can afford right now, and I like loud diesels. That said, it doesn't sound very good, and it could really be improved on a LOT.

If you're going to start with the muffler delete, I'd strongly recommend NOT deleting the remaining exhaust pipe. Just delete the muffler itself. I honestly think a simple muffler delete is a really good place to start because it's so simple and cost effective, just don't lop off everything past the muffler as well. I plan on eventually doing a 3.5-4" transition after the downpipe, big truck muffler, and extending the end to exit out in front of one of my rear wheels.

EDIT: I know you're focusing more on the technical implications of this Tugly, but on a really practical note, i've found that it is a good idea to have the exhaust exiting past the bed somewhere. That may seem really obvious, but I just sort of ignored my dad when he told me that. It's a pain to do anything underneath my truck past where the exhaust exits, because it's all covered in a thick layer of soot now. I know you're really thorough with your research before you do stuff to your truck, and I doubt you'd really just lop off your exhaust like I did anyways, but I thought I'd mention it lol.

 

That very thought crossed my mind... for about 7.5 seconds - hat's how long it took me to think of the soot all over "Stinky's" ***. The guys at the smoker's table would likely razz me with "When are you gunna put a diaper on that thing?" They already give me carp when the temp gets near zero and I plug in at work. "That's what you get for buying a Ford, you have to plug it in so it won't shiver when you start it." I get the last laugh, though - the Duramax overheats when they use the plow. I think the whistle might chill the chiding.

 

No I dont. I can take it off if I wanted, which I dont. Its quiet when I want it to be and loud when I get on it.

 

I took the muffler off when I changed the transmision on my 4x4 daully . i made pipes to exit in front of right rear wheels just make it longer than the tires or you will have the strangest looking blackwalls

 

I have run a 4" exhaust for years. No loss or gain in millage. The gain is a loss of EGTs when towing heavy. I used to run a straight pipe. The noise started to ge a little old so I added a Donaldson muffler. Adding the muffler gives me a deep tone at idle and a nice quiet ride inside the cab and the EGTs are still in check.

 

I'll be looking into that if the noise wears thin on my wife or I. I can totally understand how having a whistle around would drive one crazy - I had 3 kids in the house, years ago.