I had my 4" Pinnicle exhaust on my truck for about a month now and the noise is beginning to bug me. It has no cat and the muffler is a straight through design. What can I do to tame this system? At least make it less drony.

Any exhaust shop will convert your straight thought muffler back to a OEM type one. What your looking for in a muffler being longer, off set and it's warranty.

Can check out Flow pro #8992

http://www.flopro.com/DPmufflers.htm

Here's what your trying to get, but I don't see a 4 inch inlet/outlet muffler.

http://www.flopro.com/FP2500oval.htm

Dave

What are the dimensions of the muffler?

I went with a Walker straight-thru design. It's not bad at all.

My complaint is 'Engine' noise...

Not sure about the size.. I have to go under and measure it. It's not that bad untill I pull my trailer up hills when the engine begins to work then it's to loud to talk. Also the drone is always there..

I will measure it later today

Dave, I have the same complaint about my suburban with 4" exhaust. It's the brassy drone that gets to me. I started applying liquid sound dampener to the floors, under the carpet. There was some improvement, although I've been waiting for warmer weather to pull out all the seats and carpet to do the whole thing.

The other option that I've considered is a 4" muffler from flowmaster. From what I recall, it's about $150 and it's a 40 series. I didn't get a chance to get interior noise specs on the 40 series, but I'm guessing it's at least a small improvement over a glasspack. Before I buy a muffler, I'm going to apply more of the sound dampener and possibly dynamat on top.

Can you increase your boost pressure? This may effect the amount of noise you hear inside when pulling your trailer. When my vacuum lines broke (no boost) the interior noise was much worse. It was much brassier. I fixed the vacuum leaks and the motor had boost, more power and less noise.:grd:

Please post any results you have on interior noise control.

Wow, that's a shame it's too invasive. I have the same system and I love it. I am thinking of even removing the muffler and putting pipe straight through. Make sure everything is tight as well before you go spending $$$. Hope you get something figured out.

My 4" system was too loud at first too.. Then I found out the pipe was rubbing the frame and transmitting the noise that way as well. Now it's only too loud when my foot is on the floor with the APP under it! http://www.dieselplace.com/forum/images/smilies/rockon.gif

Ya... my downpipe was rubing the frame at first but I fixed that long ago.. Now it just loud when I give her. I thing I never did figure out is the muffler.. Does it matter which way it faces? I didn't see any markings or arrows so I mounted it with the fins facing the front. I figure it woulf catch the sound that way.. I might try flipping the muffler around.

you've got the muffler installed correctly if those tabs are pointing towards the tailpipe. I wouldn't expect major if any change in noise by simply flipping it around.

whats the best way to quiet the exhaust? turn the radio up louder.

To lessen exhaust noise: Turn up the stereo or point your 4" exhaust into one of those little cars with the thumping stereo, whale tale, and fart can muffler on it. http://www.dieselplace.com/forum/images/smilies/exactly.gif

:lol: you want it to be quiet ?? shut the truck off):h

The muffler on the pinnicle system can be mounted both ways. One will give you a louder result than the other. If you mount the muff with opening of the tabs (inside muff) facing the front, it will be quieter than if they are open towards the back. Not sure how much of a differance it makes since mine are facing foward and I can't get the muff off to compare. Maybe tomorrow, I'll see if I can get it off once more and see what she sounds like.

To lessen exhaust noise: Turn up the stereo or point your 4" exhaust into one of those little cars with the thumping stereo, whale tale, and fart can muffler on it. http://www.dieselplace.com/forum/images/smilies/exactly.gif
That's how mine is. I use it when someone won't let me over in a traffic jam. Get tailpipe right up to their driver's side window (when their's is down of course) and pump the throttle a few times. Fills the car with a nice sooty smoke and they don't like it one bit:ro) .

Go to this site and look at the Donaldson mufflers for 4" exhaust - the are called offroad series. If what they show doesn't work, there is a catalog they reference for more info, email them your address and you'll get the whole catalog in 2 days. They have some great options and I would be surprised if you can't find something that works.

http://www.donaldson.com/en/exhaust/support/datalibrary/index.html

What size are the mufflers that come on those exhaust systems? I have an almost new Allied 4" muffler in the garage that was too long to easily install on my ext. cab swb truck. If anyone is interested in it send me a PM.

Helmholtz resonator.
Non restrictive, self scavenging at (Fs) no drone in cab. Deeper exhaust note outside.

I have 3 designs up on various Cummins Engines in the PNW. The only way you could get them to give them up is to pry it out of their cold dead fingers. 150F+ EGT Drop at (Fs)

However, I have not yet mastered the V-8 Pulse. The Math is not 'behaving' properly to effectively cancel a standing wave resonance! Moving to 1/2 Wave makes the frequency bandwidth distend .... problem gets worse not better. I have been working on this for the DMX for a while. The Cummins is done. 4" 5" ... no problem. Twins? No Problem.
Duramax is stumping me. Where i might be *****ing up is the (Fs) of the entire system. At any rate, my truck is no longer suitable for testing because it has the Twins on it.

I might pres ohmylly or possibly another DMX in the PNW to do a test fit or 2
It requires 1 6" section of exhaust to be removed, and ends flanged for the unit to slip into.
Of course there are other things to make life more fun. The diameter of the pipe is not the problem as are the 6 different chassis cab arrangements that change the overall lenght of the system. What I designed for an EXT LB will not work on anything else but!

Okay, this is an old thread, but I just fixed my noise problem with my 4" exhaust. It was a January thaw when I installed the system. I started on a Sunday afternoon and finished at around 10pm that night. As it got later, I was rushing and never bothered to check the clearance on the exhaust.:o: It snowed the next day, and the exhaust system dropped to the end of my list of priorities. The darn thing has been sitting on the transfer case crossmember and resonating throughout the truck for 5 months-:t . Now that the exhaust sits where it should, no more droning inside the Suburban.:D I also installed the 5" tip that I ordered with the system. When I came inside for dinner, my wife asks "What did you do?? It's much louder.....":muahaha:

To lessen exhaust noise: Turn up the stereo or point your 4" exhaust into one of those little cars with the thumping stereo, whale tale, and fart can muffler on it. http://www.dieselplace.com/forum/images/smilies/exactly.gif

Can you imagine the look i'd get if i did that to someone....... priceless!!!

Wow CR with that smoker ya got?!! Hahahahahahah

I did that to someone once. I was in my old bronco. It had 40" tires, a 460 and dual exhaust. There's this guy in town that drives a crown victoria that he's made look like an unmarked police car (the guy tailgaits people and pretends he's a cop he deserves worse:D ). I see him coming around a sharp corner with his window down. I mashed on the accellerator and gave him loud blast of exhaust. He turned around and started to follow me....then I laughed):h .

I had my 4" Pinnicle exhaust on my truck for about a month now and the noise is beginning to bug me. It has no cat and the muffler is a straight through design. What can I do to tame this system? At least make it less drony.
Trade me for my 3" system would work for me. ):h

I would if I didn't weld some parts on. :D I'm still looking for a 4" turbo muffler. No one makes one but since Dodge is now making 4" exhaust on there new Cummins I would imagine the aftermarket will be making mufflers for it soon.

hey, y'all from a total newbie -

i just picked up my first diesel last week in memphis. driving up to illinois, i had the same thought. this weekend with the wife and mother-in-law (she loves the truck, btw) i thought the burb was too loud even though it is stone stock.

i thought i'd try:
1. wrapping the exhaust headers
2. replacing/doubling the insulating blanket on the hood
3. seeing if there was an aftermarket firewall blanket out there

has anyone tried to knock down engine noise before?

I'm still in the process of trying. I've succeeded in moving the noise from the front of the suburban to the back of the suburban:rolleyes: . a reflash is what you need. It increases the boost pressure and recalibrates the fuel curve and transmition shift points. you get more whoosh from the turbo and less drone from the engine, not to mention gobs more torque. however, you will need gauges, 3" downpipe and minimum of 3" exhaust. I have 4" exhaust and that's why mine's still noisey. I'm looking for a 4" muffler. After I find one, it should be good;) welcome to the forum