stumpmj
stumpmj Dork
4/8/12 9:24 p.m.

I've got a 2nd gen Ram Diesel. I've just finished rebuilding the front suspension so now I need to deal with the noise. The truck has a terrible resonance/boom at a bunch of differnt speeds in cluding 55, 65.... Basically, all the speeds I want to cruise at while towing. Any ideas on how to quiet things down? I'm figuring on replacing the exhaust at a minmum but I'm not sure if some strategically placed Dynamat or somethign else could cut the cabin resonance. Any good ideas?

SyntheticBlinkerFluid
SyntheticBlinkerFluid SuperDork
4/8/12 9:27 p.m.

Dynamat should help you out for the noise in the cab. Maybe a quieter diesel muffler could help out too.

calteg
calteg Reader
4/8/12 10:10 p.m.

Quieter? You're doing it wrong. Details are overwhelming. Stock or aftermarket exhaust? Rusted or not? Side exit? Stacks? Pointed at the ground? What's really bothering you? The exhaust? Diesel clatter?

novaderrik
novaderrik SuperDork
4/9/12 4:51 a.m.

wtf is a "2nd gen Ram"? they've been making those things since, like, forever- and they were putting a "Ram" badge on minivans in the 80's....

Mazdax605
Mazdax605 Dork
4/9/12 6:14 a.m.

2nd gen with the diesel. 94-02 or so I think is the 2nd gen diesel trucks.

curtis73
curtis73 SuperDork
4/9/12 7:47 a.m.
Mazdax605 wrote: 2nd gen with the diesel. 94-02 or so I think is the 2nd gen diesel trucks.

93-98.5. It refers to the 5.9L with the linear P7100 pump. First gens used a rotary VE pump, 3rd gens went to a VP44 pump and common rail (also when they went to 24 valve)

Back to the topic... Dynamat doesn't usually help with "booming" noises. It is best at damping high frequencies. Increasing the weight of a panel by adding dynamat can make it resonate at a lower frequency (which is why its so good at cutting out road noise) but at the potential expense of actually amplifying low frequencies.

Second-gen cummins are a rattly beast. I'd like to also know more about it... type of exhaust, rust, engine mounts, exhaust mounts, length of exhaust, ... The best way to make it quiet is with earplugs, but we'll try to help you out.

DrBoost
DrBoost UberDork
4/9/12 8:07 a.m.

Yeah, we need more info on the exhaust that's on there. On my first gen I had stock everything but no muffler. No booming at all. Typically, get the outlet as far away from you as you can, then point it at the ground. But, the muffler is going to be critical as well.

Ian F
Ian F UberDork
4/9/12 8:22 a.m.

I'll also agree about more info required. My '95 doesn't really "boom" at those speeds (pretty much the max speed I'll drive it) and the exhaust is pretty much a straight-through system from the turbo back to behind the rear wheel. Most of it 4" stainless with a single resonator-type muffler that does next to nothing (vs. the muffler-less set up that was on it when I bought the truck).

wbjones
wbjones UltraDork
4/9/12 4:30 p.m.
DrBoost wrote: Yeah, we need more info on the exhaust that's on there. On my first gen I had stock everything but no muffler. No booming at all. Typically, get the outlet as far away from you as you can, then point it at the ground. But, the muffler is going to be critical as well.

while pointing it at the ground be sure it's at the very end of the truck ... at/ under the bumper .... if pointed towards the ground mid-body the rebound/echo will eventually cause you to go totally nuts

DrBoost
DrBoost UberDork
4/9/12 5:11 p.m.

If you don't like the "point it at the ground" idea, you could do something like this

or if you want to get it away from the driver compartment AND don't want to point it at the ground, you could do this

stumpmj
stumpmj Dork
4/10/12 10:04 a.m.

Stock exhaust with a rusted resonator right now (although I can't feel any exhaust leaks around it right now). Maybe there's a hole somewhere I can't see. It's a 99 with the VP44. The exhaust exits to the side behind the rear wheel.

@Ian F I'm kind of suprised to hear that there isn't a boom problem. I've got a friend with that setup and his is even worse than mine is. He actually wears ear plugs while he tows because the boom is so bad. Which exhaust do you have?

Ian F
Ian F UberDork
4/10/12 10:26 a.m.
stumpmj wrote: @Ian F I'm kind of suprised to hear that there isn't a boom problem. I've got a friend with that setup and his is even worse than mine is. He actually wears ear plugs while he tows because the boom is so bad. Which exhaust do you have?

No idea. It was on the truck when I bought it. Stock-appearing down pipe off the turbo, going to 4" stainless about at the firewall. From there it's jsut straight pipe back to the axle where it goes over the axle, then bends to exit. I had to add a resonator since my mechanic wouldn't give it a inspection sticker without at least something that looked like a muffler was there. We're not convinced it made the truck any quieter at all.

It's not quiet by any stretch, but I don't find it terribly annoying. Honestly, when it was running BFG mud-terrains, the tires made a more annoying rumble. Maybe being an extra cab, the additional length helps? The picture of it in "My Garage" is from the first day I had it home.

stumpmj
stumpmj Dork
4/10/12 1:21 p.m.

Your truck looks just like mine (2nd gen extended cab). Mine's got half doors on both sides. How about yours? Hmmm.... If a stright pipe isn't painfully loud, maybe I've got a hole somewhere I don't know about. I'll have to crawl under it as soon as I get home from work before dark. I guess I could start with a 4" straight pipe and add mufflers/resonators until the noise is acceptable.
Or maybe you and I have differnt noise standards and I'd hate it.

Ian F
Ian F UberDork
4/10/12 2:50 p.m.

It's possible. At 41 years old with a history of playing a Les Paul through a 1/2 stack, my hearing isn't what it used to be...

The truck is definitely a lot quieter to ride in than my GT6, which has a bone-stock exhaust. Of course, the truck cab has a lot more/better NVH insulation.

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