Exhaust for the 7.3 Godzilla

Been communicating with a rep from MRBP. They offer a 4" longer muffler that requires relocating the front hangers to existing holes in the frame rails. The longer muffler in 301 stainless runs $150 plus $25 to ship. I had been hoping it would "burn in" and get quieter, but haven't really noticed a difference after 8,000 miles.
Maybe I'm getting too old o_O
Its a tough choice between my sanity and enjoyment derived from noise pollution directed at Prius drivers.

When is it loudest? idle? cruising? What RPM?

Thanks
 
When is it loudest? idle? cruising? What RPM?

Thanks
Low RPMs 1200-2000 rpms under a slight load. Unfortunately that's right where the 7.3 lives.
 
Yup its rite between 1200-2000rpm 100%
 
Hmm. I currently live with and love my 5.0L Mustang that I did a Roush X pipe and SLP Loudmouth axle-back (which is basically identical to a Roush axleback). It's quite loud everywhere on the RPM band. I'll see how I like the MBRP, maybe I'll add an extra Borla XR-1 in line before the MBRP if it's too much around town in the cab. Guess I'll see when I get around to installing it this summer.
 
Installed a Hooker electronic cutout the other day. Installed after the first big resonator and removed to small one to fit this in. For me the sound is just right..not to loud, but an aggressive growl when you want it. Also, it's super quiet on the highway, even while towing. It's got a nice raw sound.
Now to figure out how to post the video..
 
Installed a Hooker electronic cutout the other day. Installed after the first big resonator and removed to small one to fit this in. For me the sound is just right..not to loud, but an aggressive growl when you want it. Also, it's super quiet on the highway, even while towing. It's got a nice raw sound.
Now to figure out how to post the video
Figured it out...check out the link

 
Figured it out...check out the link

Sounds great! Would you mind sharing the part number on that setup, I’d like to mimic yours. I think it’s the perfect route to take.

Also, do you think it would be possible to wire the valve to an up fitter switch?
 
Sounds great! Would you mind sharing the part number on that setup, I’d like to mimic yours. I think it’s the perfect route to take.

Also, do you think it would be possible to wire the valve to an up fitter switch?
Thanks!

I believe this is the part number:
HOK-11057HKR

It can't be wired to the upfitter because the toggle switch to operate it does not flip into on or off positions. When you hit the toggle switch it move right back into the center position if that makes sense. Sending constant power to the motor that controls the flap would burn it out. That's what the shop told me anyways.

I think I'm going to post a cold start video if your interested. That's when the sound is most prominent.
 
Thank you and a cold start is always appreciated!!
 
This is the complete AFE System from headers to tips. I also have the AFE Momentum GT Cold Air Intake and awaiting their new Throttle Body.

Bone stock system for comparison:

Initial startup and inspection after install:

A few high revs:

The system has a really nice "lots-of-bass" sound and zero drone.

MB
 
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Any experience with aFe Rebel 409 catback on the 7.3 L?
I just installed the Rebel system along with the AFE Twisted Steel Mid Pipe and Headers and it's awesome. When newly installed, it had a bit of a brash sound for less than the first 100 miles, but it burned in nicely and has developed the rich tonal sound and performance I was after. The sound the the cab is not obnoxious and absolutely zero drone.

Here's a clip of a cold start prior to what I'd call a total burn in. You can still see particles flying out of the tips but after a few more miles, this clip doesn't do the sound justice at all.


MB
 
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What is drone? I thought it was the sound inside the cab at driving rpm....
 
I just installed the Rebel system along with the AFE Twisted Steel Mid Pipe and Headers and it's awesome. When newly installed, it had a bit of a brash sound for less than the first 100 miles, but it burned in nicely and has developed the rich tonal sound and performance I was after. The sound the the cab is not obnoxious and absolutely zero drone.

Here's a clip of a cold start prior to what I'd call a total burn in. You can still see particles flying out of the tips but after a few more miles, this clip doesn't do the sound justice at all.


MB
Awesome, I just got a set of the exhaust but not the other parts. Thanks man!
 
What is drone? I thought it was the sound inside the cab at driving rpm....
Exhaust drone is an annoying quality in many aftermarket exhaust systems and caused by a heterodyning when engine and exhaust frequencies are aligned. Generally, drone occurs within a particular RPM band (2000 to 3500 RPMs) at highway speeds. You won't hear this component in factory systems due to how they're designed to cork the exhaust through heavy resonance, etc.

The better aftermarket systems have very well designed resonators placed appropriately within the system to cancel out the frequencies that occur in the 2000 to 3500 RPM band.

MB
 
Awesome, I just got a set of the exhaust but not the other parts. Thanks man!
Awesome! You're going to be pleased, just be patient through the first 100 or so miles and the system will settle in.

MB
 
Exhaust drone is an annoying quality in many aftermarket exhaust systems and caused by a heterodyning when engine and exhaust frequencies are aligned. Generally, drone occurs within a particular RPM band (2000 to 3500 RPMs) at highway speeds. You won't hear this component in factory systems due to how they're designed to cork the exhaust through heavy resonance, etc.

The better aftermarket systems have very well designed resonators placed appropriately within the system to cancel out the frequencies that occur in the 2000 to 3500 RPM band.

MB
You are in the industry then? Generally when an exhaust is loud it drones, when it’s quite it does not.
 
You are in the industry then? Generally when an exhaust is loud it drones, when it’s quite it does not.
I'm not in the exhaust industry, but I am an Engineer (I own a gun company and design what is our product line). Whether an exhaust system has a component of drone is not proportional to how loud it is, but instead, how poorly (or not) the system is designed/executed.

MB
 
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