Quote:

Originally Posted by '88 E-350

When I finally found the local straight pipe guy at a gas station he said the same thing. None of the hundreds of people he drove past every single day ever said a word.....because it's impossible to unless you track the offender down. All the other neighbors around me talked about him and how obnoxious his truck was. If you're out in the boonies it might not be a big deal. If you live/drive in the city you are absolutely that guy that most people wish would go away.

Here’s an idea. Instead of speculating, let’s pick a phone app that measures decibels and run the numbers. Do you have a stock 7.3 Turbo Diesel from 99.5-2003 with a stock intake, filter and exhaust? We do not. I can get data from three trucks. All have the AFE intake, all have the 4” straight pipe after turbo exhaust, but one also has the Banks equivalent of an exhaust brake.

Let’s measure decibels at:

1. Idle
2. 5 MPH
3. 15 PMH
4. 25 PMH
5. Others?

From a distance of x feet?

Any other things to include in this test?

All the best,
Mike

 

I would assume that what this guy is referring to is if you were to straight pipe a newer diesel with the emissions equipment. Mainly the DPF and/or EGR. On newer trucks, if you remove these items, you need to update the tune so the computer will not try to use these functions, but the truck is most definitely going to run better without the emissions equipment.

 

I'm down. I don't think that many speeds are needed. I would say idle, max revs in neutral, and a drive-by at 25 to 35 MPH should do. The only 'mod' on mine is that the plastic housing that extends from the air cleaner to the front is missing, but I doubt that would make a big difference. I assume different phones and different apps would give different readings. I have an iPhone 5s and no Db apps, but I'll load any free one.

Without hard numbers I can say that I never hear a stock one drive by my house if I'm inside and there are a few that live in the area. I hear the modded ones. If I'm in the front yard I'll hear the clatter of a stocker drive by, but it's fairly faint, I hear the exhaust over the clatter on modded ones. The straight pipe one I could clearly hear from any part of the house day or night. He drove fairly mellow, regardless, if I was outside I could count the shifts as he went down one street, turned onto my street, then past my house up to at least 3rd gear, sometimes forth during the day. At night from inside the house I'd hear him till he let off for the stop sign 1/4 mile past my house, then again as he left the stop, then again as he left the light past the stop. If he turned south I'd hear him through 4th gear, northbound he'd fade away quickly.

 

No tuning needed for straight pipe. It will likely save you some mpg, but won't get you much performance.

It would really only matter if you're running a chip, or have other performance enhancements. As they'll allow more fuel/air to the motor. Then the exhaust changes will matter.

The stock tuning on the 7.3 is so mild that exhaust changes won't really do anything without other changes.

It's down tuned for the epa, even though it's capable of much more,so the tuning would be the bottle neck, before the exhast is.

 

this would apply if it was dpf equipped

maybe hes confused

 

Some gassers don't respond well to straight pipes.
There's no need for a tune on a 7.3 with straight pipes. If you're towing you might regret not going with a free flowing muffler.