The aggressive sound of a five-inch straight pipe is unmatched, but the constant highway drone, especially when towing, can be brutal. Kyle Redekopp of Dark Iron Diesel tackled this exact problem.

“I love the sound of the five-inch straight pipe,” he said, “but lately we’ve been doing a lot of towing with the fifth gen, and the drone is getting old.” His solution was to test a unique new product designed to offer the best of both worlds.

The Thunder Muzzle: A Switch-Flipping Solution

The product is an actuated muffler from Glory Day Speed Shop. It’s not a typical muffler; it features an internal electronic valve that allows the driver to switch between two exhaust paths on the fly.

In the open position, it’s a true five-inch straight pipe. In the closed position, the valve redirects exhaust gases through a baffled chamber, quieting them down significantly. After installing the Muzzle, Kyle was immediately impressed with its effectiveness.

The Sound Test

A quick sound test in the shop and on the road revealed a massive difference between the two modes. “That is absolutely insane. That is like a night and day difference,” Kyle exclaimed after flipping the switch from open to closed.

He noted that the quiet mode would be a huge relief for long towing trips where the drone can become deafening, while also allowing him to pass vehicle inspections without giving up his straight-pipe sound permanently.

The Dyno Verdict

With the sound difference confirmed, Kyle put the truck on the dyno to answer the big question. “I wonder if the muffler actually does lower horsepower, and we’re about to find out,” he said. He performed multiple runs with the muffler open and closed.

The results were surprising: there was no power loss at all. The open runs made around 390 horsepower, while the best run of the day, 395 horsepower, actually came with the muffler closed. Torque remained consistent at around 810 lb-ft in both settings.

Thunder Muzzle: The No-Compromise Muffler

In the end, the Thunder Muzzle lived up to its promise. The dyno test proved that quieting down the exhaust didn’t come with a performance penalty. “That’s good news, guys,” Kyle concluded. “That means that if you do want to close your muffler off so that it’s not loud, you’re not sacrificing power and torque.”

The actuated muffler is a true no-compromise solution, finally giving truck owners the ability to have an aggressive straight-pipe sound when they want it and a quiet, comfortable ride when they need it.