Muffler Recommendations? Straight-Piped ATM

[andrewbourdeaux]

Hey guys! I am looking to get a muffler for my 7.3 IDI NA. I went straight-piped a while back and liked it at first, but it's straight up obnoxious and gets on my nerves now! I'd like to keep the lower tones and cut out the raspy bite. Let me know if you have any recommendations!

 

[CADHOWDY]

A FLO-PRO twister muffler/resonator is a simple and relatively inexpensive bottle style unit that really cuts down on drone and high RPM exhaust rap. Leaves you with a very satisfying low rumble and growl and doesn't restrict flow much at all.

 

[Sergey]

Hey guys! I am looking to get a muffler for my 7.3 IDI NA. I went straight-piped a while back and liked it at first, but it's straight up obnoxious and gets on my nerves now! I'd like to keep the lower tones and cut out the raspy bite. Let me know if you have any recommendations!

Days back when I threw away my truck's rusted (and likely partially clogged) muffler I was going to install something like this one on photo below.
But, after talking to a friend who has installed similar muffler and listening to his exhaust sound I was not convinced - that muffler was entirely eliminating higher frequency sounds so that I could not hear turbine spinning at all. Maybe it's my loss of hearing. But with straight pipe I can hear turbo working properly. Again, maybe it is just personal perception and hard of hearing, but I found straight pipe not too loud with 6.9 IDI turbo.

 

[IDIBRONCO]

A turbo really does quiet down a straight piped exhaust.

 

[Fredrickson]

I have a very similar set up .. 1994 Ford E350 7.3L IDI NA Ambo.

It is mostly white with w/ a red stripe.. (mundane)
Straight piping it or making it throaty would be like putting glass packs on a Buick Estate wagon with faux wood paneling.

I have a NAPA muffler (part number EXH 21475).
It's quiet enough.. and at idle says "blub blub blub blub blub"

 

[andrewbourdeaux]

@Sergey Thank you for your advice, however, I am non-turbo. My current straight-piped setup is just too loud, especially when climbing up a hill and the windows are down, or driving on the highway next to a cement wall on the passenger side. It really is loud!

@IDIBRONCO I would like to get a turbo on this big dog of a truck. Any kits you know of that will fit the van chassis?

@Fredrickson That muffler is very similar to the one that I removed a while back. It was too quiet and I wanted some grunt. Turns out it has far more grunt than I thought it would! Now I just want to cut out the sharp rasp and leave the low end.

@CADHOWDY I am going to order this up. I will record a before and after and post it once it's all set up! Thanks for the recommendation!

 

[andrewbourdeaux]

@CADHOWDY Would you go with a 12 in. can or 17 in. can? Thanks!

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[u2slow]

A larger diameter straight pipe also drops the tone. 3" on my Cummins was much choppier than 4".

 

[IDIBRONCO]

@IDIBRONCO I would like to get a turbo on this big dog of a truck. Any kits you know of that will fit the van chassis?

I know that those kits were made. As far as current availability, Hypermax shows a turbo kit of vans, but I couldn't find a listing for vans from Banks. Those are the only two manufacturers offering complete turbo kits for our engines as far as I know.

 

[CADHOWDY]

I myself went with the longer one.

 

[TNBrett]

Close to 25 yrs ago I had straight pipe true dual exhaust on a 7.3 NA. It was absolutely horrible. It would set off car alarms if I was really getting after it in a parking lot. I ended up with a y pipe to join them back together and a single inlet dual outlet 40 series flowmaster. That was the hot thing at the time with all my high school buddies. It was much better, but I was never really thrilled with it.
I’m a fan of the spiral type mufflers now though. I’ve never heard one on a diesel, but I used the Moroso Spiral Flow mufflers (looks pretty much identical to the Flo Pro’s posted earlier) on a truck I built a few years ago. It had a 2004 Chevy 4.8 gas that was bone stock otherwise. It did a really nice job of giving it a low rumble.
https://youtube.com/shorts/LEwqXfiFi7Q?feature=share

 

[Sergey]

A turbo really does quiet down a straight piped exhaust.

Maybe so, although a friend of mine had 6.9 NA with straight pipe and it was not too loud for me, I drove it a couple times. Maybe hard of hearing Heck I should have audio recorded to share.

Anyhow, the only time I feel my straight pipe exhaust becomes loud is when I downshift from 3rd to 2nd with engine breaking. That is during deceleration exhaust sound is the loudest, not during acceleration.

 

[andrewbourdeaux]

@Sergey Since I sit right at 12,000 lbs, I am basically driving like I am towing everywhere. I have wondered if I would be quieter without my weight, being that I would need less pedal to get around.

 

[chillman88]

@Sergey Since I sit right at 12,000 lbs, I am basically driving like I am towing everywhere. I have wondered if I would be quieter without my weight, being that I would need less pedal to get around.

I just have a glass pack on my dually. I probably weigh about half of what you do. The glass pack really isn't that loud.... Until I'm trying to pull a loaded trailer up a grade which gets old fast.

I know where you're coming from and yes, I think if the extra weight wasn't there you probably wouldn't mind it.

I plan on a straight pipe once I turbo it, because I've heard how much a turbo will tone it down, plus mine is currently dumped right under the bed, and the new exhaust will let out behind the tire where it's supposed to be which should reduce a lot of the drone.

I also don't live in the city where people will complain about my noisy smelly truck, so there's that

 

[IDIBRONCO]

I know where you're coming from and yes, I think if the extra weight wasn't there you probably wouldn't mind it.

I have to agree with this. When I was running my first 85 F250 both N/A and straight piped, it didn't seem nearly as loud when I wasn't accelerating. That was in the cab. How it sounded to the people on the outside, I have no idea.

plus mine is currently dumped right under the bed, and the new exhaust will let out behind the tire where it's supposed to be which should reduce a lot of the drone.

From my experience, that makes quite a bit of a difference.

I also don't live in the city where people will complain about my noisy smelly truck, so there's that

You have a middle finger to fix that don't you?