We want to speak to all the readers who are over 25 years old for a minute. After all, this new muffler is specifically going to appeal to you-still liking the loud rumble of a throaty V-8 when on the throttle, but tired of waking up your neighbors when you drive home at midnight. Open pipes, gutted mufflers, bored-out cats-those are cool when you're young and driving just few miles a day. But when you start getting a little older, you start to hear a ringing in your ears, and you start noticing people looking at you like you're an A-hole, many of us will give up the thunderous pipes on our trucks for something a bit more tame around town.
And this is why Dynomax released their new VT muffler. The VT stands for Valve Technology, and the butterfly valve built into the muffler is what makes it so trick. The muffler stays quiet when driving normally around town or on the highway, but when you hit the throttle and push more exhaust down the pipes, the valve opens up, allows the increased airflow to exit smoothly, and make a throaty rumble that reminds you it's a Dynomax performance muffler.
We drove down to Mesa Muffler in Costa Mesa, California, to put one on a friend's '07 Chevy 1500 to try out in place of his stock muffler. Our friend was really concerned about being too loud around town, but liked the idea of his truck getting loud when he gassed it. We knew he was the perfect candidate.
A half-hour later, Mesa Muffler had welded the new VT muffler in place of our stock one, and we were on the roads trying it out. Was our friend happy? Oh yes. The exhaust is almost silent when he's cruising, but it gets loud when he stomps the gas pedal. Interested in what it sounds like? Check out www.off-roadweb.com/videos/index.html.
 |  1. Though the new VT muffler...  1. Though the new VT muffler is quite a bit smaller than the factory one, we found the Dynomax unit to actually be a little quieter when cruising! |  2. Here's a look down the...  2. Here's a look down the VT muffler to see the butterfly valve that opens with exhaust pressure. A simple coil spring built onto the valve keeps opposing pressure on the valve. |
 3. If you're replacing a short...  3. If you're replacing a short enough muffler, you may be simply able to cut the original muffler off and put this one in place using the provided exhaust clamps. But since we had to add some extra pipe into our exhaust (remember our factory muffler was longer than this VT unit), there was welding to be done no matter what, and Bud at Mesa Muffler decided he'd do us a favor and just weld everything up. We cut the clamp-on ends off to give a smooth weld-surface. |  4. The Dynomax VT mufflers...  4. The Dynomax VT mufflers come in a number of pipe diameter and length configurations. The offset/center inlet/outlet muffler can be gotten in 14- and 19-inch lengths for 2.25-, 2.5- or 3-inch-diameter exhaust, and the offset/offset muffler can be had in 16- and 21-inch lengths for 2.5-inch exhaust. |  5. We pulled our test truck...  5. We pulled our test truck out of Mesa Muffler and went for a ride to find the VT muffler working exactly as Dynomax said it would. And though the muffler will gradually get a little louder at full-throttle since it's a glasspack design (glasspacks break in as the fiberglass packs down), it will remain almost silent when while cruising and the butterfly valve isn't fully open. |