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Discussion Starter · #1 ·
Just installed the Vararam CAI, Magnaflow 10789 Y pipe and Magnaflow 16869 Cat back exhaust; Initially we routed the driver side exhaust pipe over the cross member and across the back of the transmission instead of across the pan in front of the cross member.
This configuration gave me a terrible drone between 1800 and 2000 RPM.
I went back to the muffler shop and had them route the pipe from the driver side the way it was original. Still have the drone but it’s not as loud and no longer vibrates under my feet. I made an appointment to have under coat and sound proofing tomorrow. I’m hoping to bring the noise level down just a little more at cruising speeds.
I can say without a doubt that adding the Vararam CAI, magnaflow 16869 cat back, 10778 y connection increased my MPG. Before 12/17 – After 15/21. Also, the throttle response is noticeably improved.
Any ideas on eliminating the drone without losing performance?
 

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I had to put the stock resonator back on my old Dakota when I went with dual exhaust. Mine had an upstream resonator, a HUGE muffler, and another resonator at the tail...stock.

The drone was terrible once it reached 50-58 mph in 5th gear...put the first resonator back on and it was still there, just not quite as bad.

Resonance is all about giving the exhaust gases somewhere to expand...perhaps put a glass pack or similar expansion chamber before the muffler?
 

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Discussion Starter · #4 ·
Had the undercoat and sound protection installed today, it is still too loud and the drone would be too much for highway driving. Talked to the dealership and they believe installing the original resonators will help but they are restrictive. Magnaflow customer service recommended I install a magnaflow glass packed muffler 18129 before the 22” muffler that came with the cat back system. If this doesn’t work, I’ll remove the 18129 and install the factory resonators.
 

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http://www.secondskinaudio.com/index.php

Look into luxury liner or luxury liner pro. Its covering my truck from the front of the footwells to the rear under seat storage and that along with the other sound deadener i have for the audio I hear 0, like absolutely 0, road noise
 

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installing the original resonators will help but they are restrictive.
Have you looked through them? The ones on my old 05 Dakota were completely open inside...I could see all the way through...it was really just an oblong muffler looking thing with some packing around the outside...just a place for the gases to expand. I did not notice any loss of performance putting the resonator back on...just a little (and I mean little) quieter. It actually sounded better, more defined...and lost the annoying cackle when decelerating.

Hope it helps, good luck!
 

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Had the undercoat and sound protection installed today, it is still too loud and the drone would be too much for highway driving. Talked to the dealership and they believe installing the original resonators will help but they are restrictive. Magnaflow customer service recommended I install a magnaflow glass packed muffler 18129 before the 22” muffler that came with the cat back system. If this doesn’t work, I’ll remove the 18129 and install the factory resonators.
That muffler is 2.5", you need 3" like this one:
http://www.magnaflow.com/02product/shopexd.asp?zone=main&id=9531
 

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Discussion Starter · #8 ·
Mikeb33,
Thanks for pointing out the difference in the core size.
 

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I believe the resonators are hollow and they are designed to tune out the drone from our standard muffler system.

Mikeski...
 

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I believe the resonators are hollow and they are designed to tune out the drone from our standard muffler system.

Mikeski...
I think this is correct. Our stock resonators don't have any restrictor or baffle in the flow path, do they? I thought I recalled someone posting a Ram resonator cut open to show what they looked like. In fact I think most resonators are not restrictive to flow, but have vents, bulges, and bends inside them to attract and modify sound waves, not exhaust pressure. There are computer programs that are supposed to show an exhaust engineer what length, diameter, and internal design of a given set of resonators work with a given engine. I think there's supposed to be some actual science as to how they tone down unfavorable exhaust sounds without restricting flow.

However, on the drone of our hemis with a higher flowing and slightly louder exhaust, I think it's going to exist with MDS engaged to some degree. The resonators do seem to reduce it as noted by many forum members. I have a Borla straight-through muffler with OEM tailpipes and resonators. I only notice the MDS when driving slowly and just cruising at a steady pacea around town. At highway speed it's practically nonexistent. People are very different in their sensitivity to this sound.
 

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Discussion Starter · #11 ·
6 inch round magnaflow installed as resonator.

I installed a magnaflow 12649 3in in/out (3in core) as a resonator. The drone is gone and it sounds stock again. I have to admit I miss the tone it had before but I will drive it for a while to see if it suits me.
 

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I installed a magnaflow 12649 3in in/out (3in core) as a resonator. The drone is gone and it sounds stock again. I have to admit I miss the tone it had before but I will drive it for a while to see if it suits me.
I'm glad it got better for you. I can imagine the disappointment after all those parts to hear it drone.

Do you still feel it sounds stock? How about when you step on it?
At least it is all straight through and you still have your power and mileage gains.
 

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Any update after a few miles? Still happy?
 

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Bump

Any update on the sound after a year. How does it sound and perform?
 
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