A quiet exhaust for me!

[crispyboy]

An exhausting story - for those folks who may be seeking a quiet exhaust on your truck when you delete.
Last November after the second turbo had to be replaced at 80k miles (both only lasted 40k miles) I made a decision that I wanted to delete the egr system on my truck. The biggest issue for me was that I didn't want a noisy, droning truck. I hate drone as it gives me a headache plus I wanted the truck quiet so because it is used for traveling, I like to hear the radio and the wife and daughter like to converse. Enough said.
I saved up a few bucks for the project and finally did it back in May of 2018.

Here is what I did with great results:
- EFI tune
- unplugged the EGR and associated components under the hood per the directions
- left the stock downpipe in place. The stock downpipe is double walled with the catalyst which I knew would cut down on the turbo whistle and exhaust noise from the firewall/floorboard area.
- sold off the DPF and Noc filters. Before selling them off I cut off the flange that had the exhaust hanger attached. I welded a piece of 4" exhaust pipe to this and bought a piece of exhaust gasket paper bought at the local parts house.
- purchased a Pro-flo #8990 baffled style muffler, band clamps and placed it between the downpipe and stock muffler. The Pro Flo and stock mufflers are both straight through like a shot gun barrel mufflers. These both are more like resonators than a muffler. I kept the stock muffler in place because it had some nice exhaust hangers built into it. I also had to put a small piece between the new muffler and the stock muffler for a connection.

I downloaded a decibel app for our Ipad and took measurements both before and after the delete and exhaust modifications.
The measurements were taken at:
- cold idle - inside the truck windows closed, at the exit of the exhaust pipe and standing next to the truck on the passenger side.
- hot idle - taken at the same locations
- driving down the highway at 60 mph
The results were no discernable differences to my ear and the Ipad only showed 1 or 2 decibels different. There is no tinny sound or turbo whistle to be heard. Except for the now internally black exhaust pipe no one would ever know the truck was deleted. I met my goal!

 

[petersonj]

Nice job! I can't believe how many people do the "deletes" on trucks like yours and they end up noisier than my second generation truck. If I had a truck like yours and had the problems that you did, I would have been looking for a solution such as you came up with.

- John

 

[slowmover]

I certainly agree about sound level.

Where the engine noise is about the same or higher than the exhaust worked for me. The original owner had installed a big fart can end and lost the OEM muffler in favor of a non-resonated system. Sure, fun on start-up, but the drone at highway towing speed unbearable.

Bought a ROKKTECH chambered muffler right away and never looked back. Eleven years and 100k miles, I’m happy to not wake up the neighbors with (what too many CTD owners ignore) the sounds of a garbage truck with a broken exhaust system. (“Oh, good, they’re here to empty the dumpster”).

Backpressure was the concern past that. I wasn’t willing to lose MPG (stock truck). That remained unchanged.

I haven’t ever gotten around to it, but some day may changeover system to 4.0” from the factory 3.5. This sort of change with the big blocks of old allowed an engine to hang on just a little longer before a downshift on a grade (Towing). It would also simplify the choices about adding an exhaust brake (which I may never get to; trailer disc brakes a better use of the money).

I may also change the outlet location to under bumper with a diffuser versus the stock starboard rear wheel straight-cut outlet for the same reasons: engine noise is loud enough to bystanders, so let’s get the rest optimized first (exhaust sound at a distance).

Quiet as these trucks were when new, the latest are virtually silent. This truck now considered “loud”.

The Cummins fender badge ought to be confirmation enough for anyone that it’s a diesel, IMO.

 

[cerberusiam]

The VG turbos are pretty good mufflers to start with, all that is needed is a 24" resonator and problem solved. Takes all the drone out of a deleted engine and straight pipe. Wasn't bad to begine with but right at cruising speed with the manual it was noticeable enough to be annoying.

 

[TravisBartholomew]

An exhausting story - for those folks who may be seeking a quiet exhaust on your truck when you delete.
Last November after the second turbo had to be replaced at 80k miles (both only lasted 40k miles) I made a decision that I wanted to delete the egr system on my truck. The biggest issue for me was that I didn't want a noisy, droning truck. I hate drone as it gives me a headache plus I wanted the truck quiet so because it is used for traveling, I like to hear the radio and the wife and daughter like to converse. Enough said.
I saved up a few bucks for the project and finally did it back in May of 2018.

Here is what I did with great results:
- EFI tune
- unplugged the EGR and associated components under the hood per the directions
- left the stock downpipe in place. The stock downpipe is double walled with the catalyst which I knew would cut down on the turbo whistle and exhaust noise from the firewall/floorboard area.
- sold off the DPF and Noc filters. Before selling them off I cut off the flange that had the exhaust hanger attached. I welded a piece of 4" exhaust pipe to this and bought a piece of exhaust gasket paper bought at the local parts house.
- purchased a Pro-flo #8990 baffled style muffler, band clamps and placed it between the downpipe and stock muffler. The Pro Flo and stock mufflers are both straight through like a shot gun barrel mufflers. These both are more like resonators than a muffler. I kept the stock muffler in place because it had some nice exhaust hangers built into it. I also had to put a small piece between the new muffler and the stock muffler for a connection.

I downloaded a decibel app for our Ipad and took measurements both before and after the delete and exhaust modifications.
The measurements were taken at:
- cold idle - inside the truck windows closed, at the exit of the exhaust pipe and standing next to the truck on the passenger side.
- hot idle - taken at the same locations
- driving down the highway at 60 mph
The results were no discernable differences to my ear and the Ipad only showed 1 or 2 decibels different. There is no tinny sound or turbo whistle to be heard. Except for the now internally black exhaust pipe no one would ever know the truck was deleted. I met my goal!



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Looks like a similar muffler that came with my AFE 4" turboback system. Simple straight through design. #ad