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Exhaust sound after downpipe

15K views 17 replies 16 participants last post by  MudDoc 
#1 ·
Since I put on my MBRP downpipe a couple weeks ago, I cannot figure out why there is such a big difference in the exhaust tone at 3/4 and full throttle. It seems quieter like I put a muffler on it and doesn't have that Duramax 'scream'. Everything else sounds normal though with more whistle like it should. It's just 3/4 and full throttle.

I checked 3 times for leaks anywhere from the turbo back and found none. Boost is right where it should be and she still boogies down the boulevard. Nothing else has changed, but I thought it would be louder if anything? Has anyone else noticed something similar after the MBRP dp? Only thing left I can think of is to change my vane position to see if that changes it?

Please no answers about fuel filter or other crap. I'm not dumb so let's rule all that nonsense out.

Thanks guys, Tyler
 
#5 ·
I thought about that too, but I've never heard a Dmax with this kind of tone :confused: I just didn't know if anyone else noticed this kind of difference after the MBRP dp.

I just like being obnoxiously loud. Maybe it's time to throw on a 5" instead :confused:
 
#6 ·
I think the woosh sound is from the nasty bends and restrictive shape of the factory downpipe. The bigger and better flowing downpipe lets the air flow in a smoother path, so it doesn't get the woosh sound, if thats what your talking about.
 
#7 ·
I don't think we're talking about the same sound Jesse. I'm talking about when the rpm's get high enough and you hear the 'scream'. It just sounds like someone put a muffler on there. Maybe I have something else going on and it was just weird timing.
 
#9 ·
Go ahead, I'll buy the mbrp from ya!
 
#10 ·
Im putting a profab dp on mine this weekend and from what I hear it gets rid of the jet engine sound. I have a 5" straight on mine and I plan on taking video before and after to see the difference. Hope it doesnt get to quiet.
 
#13 ·
The sound of mine also changed with the MBRP downpipe. As said above, i figured it was because it was less restrictive??
 
#14 ·
I think with the stock downpipe a vvt turbo truck sounds like a 12 year old girl screaming.....and with the new dp she grew some hair on her chest and her balls dropped....
 
#15 ·
Its actually louder at the tail pipe but quieter in the cab
 
#17 ·
VVT trucks are weird. Mine was quiet after straight pipe install but got louder over time. Maybe it just changed the " drone " in the cab due to less restriction. Sounds like u may be ready for a stack if you want louder. I love how mine is quiet in the cab until you kinda boost it.
 
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