I'm sure many people on this board want a better sounding exhaust on their rigs but if you are like me you don't want to deal with a lot of drone and interior resonance in the truck driving to work or that multi-hundred mile trip to the trail (or waking up the kids and wife when leaving for work in the morning).
Enter the Dynomax VT mufflers. http://www.dynomax.com/mufflers.php?muffler=vt
On paper they sound perfect for this application. Quiet for cruising through the neighborhood in the morning and on the highway, but hammer on the gas and it will be fairly loud. With the current $25/muffler rebate the price is reasonable compared to other brands.
I picked up a pair of p/n 17157 3" versions that they recommend for dual applications and grafted them into the stock pipes in my '02 2500HD 6.0L Chevy truck. The stock setup is a 3" pipes off both sides of the engine with the driver's side crossing over the passenger side. The dual 3" pipes run side by side down the passenger side with a cat on each, then into a stock duel inlet, duel outlet muffler. After the muffler it Y's into a single 3.5" tailpipe.
The good:
- mild idle, but noticably more aggressive then stock
- mild cruising the neighborhood
- quiet on the freeway (almost as quiet as stock)
The bad:
- rattles/clangs very loudly......enough that the neighbors will turn around and look at you when you drive by. Reminds of those flappers (rain guards) on the exhaust stacks of farm equipment. Double-checked everything and the noise is definitely inside the mufflers.
- under light to moderate throttle it seems like the valving is fluttering and almost sounds like the engine is missing.
- doesn't seem much louder than stock when stomping the throttle...so what's the purpose of spending the money, right?
Per Dynomax the first set was taken back and exchanged for two more, which did the exact same thing when installed. They all came from Jeg's (I'm local to their retail shop) and were in sealed boxes with no obvious signs they had been damaged in shipment.
I talked with one person from Dynomax who mentioned they had a bad batch some from the factory (incorrect valve tolerances or something) and they could send my a pair factory direct. It was the end of the day so they would call me back but never did. Several days of calling and finally got to talk to somebody but they denied the above. When I removed this second pair and looked inside it was easy to see where parts of the valve were contacing the sides of the internal pipes and hence the rattle/clinging. Even a couple thousands inch off in a few places would probably prevent this.
Yesterday I replaced the VT's with Dynomax Ultra-Flo mufflers (exact same dimensions, and basically the same muffler minus the valve). At idle, light cruising in the neighborhood or on the freeway there is not a significant difference in interior resonance or sound. They do have a little more sound during acceleration than the VT's, which I like. So far the only real difference is that the VT's are more expensive and sound like somebody is shaking an empty soda can full of rocks next to you.
Enter the Dynomax VT mufflers. http://www.dynomax.com/mufflers.php?muffler=vt
On paper they sound perfect for this application. Quiet for cruising through the neighborhood in the morning and on the highway, but hammer on the gas and it will be fairly loud. With the current $25/muffler rebate the price is reasonable compared to other brands.
I picked up a pair of p/n 17157 3" versions that they recommend for dual applications and grafted them into the stock pipes in my '02 2500HD 6.0L Chevy truck. The stock setup is a 3" pipes off both sides of the engine with the driver's side crossing over the passenger side. The dual 3" pipes run side by side down the passenger side with a cat on each, then into a stock duel inlet, duel outlet muffler. After the muffler it Y's into a single 3.5" tailpipe.
The good:
- mild idle, but noticably more aggressive then stock
- mild cruising the neighborhood
- quiet on the freeway (almost as quiet as stock)
The bad:
- rattles/clangs very loudly......enough that the neighbors will turn around and look at you when you drive by. Reminds of those flappers (rain guards) on the exhaust stacks of farm equipment. Double-checked everything and the noise is definitely inside the mufflers.
- under light to moderate throttle it seems like the valving is fluttering and almost sounds like the engine is missing.
- doesn't seem much louder than stock when stomping the throttle...so what's the purpose of spending the money, right?
Per Dynomax the first set was taken back and exchanged for two more, which did the exact same thing when installed. They all came from Jeg's (I'm local to their retail shop) and were in sealed boxes with no obvious signs they had been damaged in shipment.
I talked with one person from Dynomax who mentioned they had a bad batch some from the factory (incorrect valve tolerances or something) and they could send my a pair factory direct. It was the end of the day so they would call me back but never did. Several days of calling and finally got to talk to somebody but they denied the above. When I removed this second pair and looked inside it was easy to see where parts of the valve were contacing the sides of the internal pipes and hence the rattle/clinging. Even a couple thousands inch off in a few places would probably prevent this.
Yesterday I replaced the VT's with Dynomax Ultra-Flo mufflers (exact same dimensions, and basically the same muffler minus the valve). At idle, light cruising in the neighborhood or on the freeway there is not a significant difference in interior resonance or sound. They do have a little more sound during acceleration than the VT's, which I like. So far the only real difference is that the VT's are more expensive and sound like somebody is shaking an empty soda can full of rocks next to you.
