Deeper engine noise after exhaust add

Is it typical to have much deeper engine noise after exhaust add? I love the exhaust sound but when driving around town or hills, light throttle, sometimes when slowing down, downshifting, theres so much bass/hum it basically vibrates the interior. I do have sensitive ears and had inner ear issues in the past maybe im just sensitive to it. I have the 12” dirty deeds system.

 

Yup, its drone. Did you get the resonator? You need the resonator to cancel the drone.

 

I had a 10 inch DD exhaust last year.

I had the resonator.

I still had major drone as you describe no matter what i did

ultimately i put the stock muffler system back on and the result was no vibration and complete silence

 

Yea Ive got the res installed

 

im tempted to do that. I had the 8 but swapped to 12 thinking that would fix this issue. But its no different at all. Maybe even worse.

 

25-55mph it was mind numbing for me. It resounded in my ears and my head. I couldn’t handle it.

 

yep thats when i notice it the most. Alot of times ill hafta get off the throttle to make it stop or either speed up to make it stop

 

I have the DD 14” system. On average, the noise level only marginally increased over stock but the tone/note in the cabin is much much better. While cruising, the truck may even be quieter. I am very happy with the setup.

I do get a rumble/deep sound when RPM’s are ~1k and I press gas pedal lightly to try and increase speed ever so slightly. To me it sounds like the engine is bogging down, giving it gas when it’s not in the powerband. Truck did this stock also, it just wasn’t as noticeable with the stock muffler.

If I press gas enough for truck to downshift, the noise disappears.

I’ve played around with the truck in sport mode(shifter kicked to left to let me change gears). If I keep the truck out of 6th gear when going under 55mph, I never get the rumble. It holds RPM’s slightly higher through the gears which is actually pretty cool. Cruising in 6th doing 65-70+ doesn’t have any issues because the RPM’s are up to 1,500 +.

 

Maybe i shoulda done longer mufflers i dunno. Theres literally no difference in the 8 and 12 with this sound im talking about tho. That was the whole reason i switched. The deep hum/drone is brutal. I checked for exhaust leak or anything but ive got everything properly installed

 

If going from 8 to 12 didn’t cause a noticeable difference, I don’t think an extra 2”-4” would make a difference. Have you called Keith to get his thoughts?

Are you getting the noise through the RPM band at those speeds or is it specific to a range like mine?

I feel like the truck shifts to 6th as soon as I get to speed (for gas savings) and requires a meaningful step on the gas for it to downshift so the truck gets in the powerband to accelerate. (My test of moving shifter to manual mode confirms this).

If the truck downshifted quicker, this could be eliminated (in my instance at least).

 

my $.02

the TRD system - which is sorta comparable to the 14" drones a tad. 1300-1400rpm

my remedy...don't go that speed.

 

I think it is person to person i have th 8 DD and no resonator and do not notice the exhaust or the drone.

 

The DD resonator works to kill drone, but it is still a very loud exhaust

 

Im running the 10" DD no res and find the drone minimal. If I have the back window down it is a little more pronounced. The wife and kids barely notice the exhaust in general unless i romp on it with the windows down lol

 

ive got the res on , the exhaust itself when gunning it sounds amazing, but creeping around at slower rpms, up hills, light throttle it sounds like i have a 12 inch subwoofer stuck under the cab. Just alot of vibration,bass,deep frequency.

 

That’s probably the rumble coming out of the pipe. I had a 10 inch. I loved it but the sound was just too loud towing a travel trailer with the fam. No drone, just that deep rumble

 

What do u have now?

 

Perhaps a longer resonator would help. Or maybe the resonator is on but the hole never got drilled to make it functional

 

Drilled the 2” hole Unless i didnt line the hole on pipe with hole in resonator properly somehow. However while waiting for 12” to arrive i used the stock system with resonator and the stock system was much quieter than without the res. So im guessing i installed it correctly

 

I have a 5x11x22 magnaflow. Ive had it since 2011, just hair deeper than stock, but silent in 5th gear pulling trailer

 

does the magnaflow have this same deep bass-ey sound in the cab?

 

Even the stock exhaust has drone if you listen for it. DD resonator will make it go away.

I have the 10in DD system, ran without and then added resonator and I think the sound is perfect.

 

no, it’s barely louder than stock

 

First off, call Keith and ask his input. He will help you if you need to change it to the larger system.

Drone is definitely problematic in our trucks with modified exhaust. If you remove the cats it's ten times worse.

Best things to do is get the resonator, don't dump pipes before the axle, and got as big a muffler as you can in there.

 

My stock exhaust did not have the same drone frequencies as the DD.

I don’t think it’s the noise that’s the problem,it’s the frequency

 

Ive got the resonator on it. I had the 8” at first. Ran with no res for a bit then installed the res. Definitely made a difference but it didnt help all that deep,bass-ey, low frequency hum at lower rpms, deccelerating,etc. i figured the larger 12” would lessen that particular frequency but it didnt

 

What about at cold start, did you notice a difference from 8" to 12"?

 

Not alot of difference imo really

 

I have the same drone with my 12" BAM with res around 1,100 rpm especially on hills. I'm sure it's installed correctly so I figured it was normal. I wish it wasn't there but the exhaust sounds so good everywhere else that I'm okay with a bit of drone in that specific situation.

 

Yea thats where it mainly is in that 1100 rpm range. Wish there was a way to minimize it