When the work day ends, many truck owners spend their hard-earned money upgrading their rigs. They improve their trucks by adding a larger turbo (or turbos), bigger injectors, custom tuning, and other performance and reliability mods with high hopes of making a lot of horsepower and torque. With that in mind, we thought it was important to share a discovery made by our friends at Firepunk Diesel. Check out any forum or social media page, and you’ll find discussions about a potential exhaust upgrade and even part removal. The guys put the theory to the test by looking at a truck’s exhaust resonator.
Three years ago, team Firepunk released a video on their YouTube channel about exhaust resonators. They questioned whether or not it was worth it to keep the exhaust quiet when measuring horsepower and torque. The theory was, that this restriction in the exhaust would be enough to rob useful horsepower and torque. Until then, that theory hadn’t been tested. Firepunk did just that in the video with Emanuel Yoder’s 2008 Ram.
Under the hood was a set of 100-percent-over-stock injectors, a 12mm CP3 pump, and a S476 turbocharger. After carefully calibrating the truck, Firepunk ran out of steam at 720 horsepower. “Emanual’s truck was making 44 to 45 psi of boost pressure, but we really expected more in the 50 to 55 psi range,” Larson Miller said. “Then, afterward, we discovered there was a resonator in his exhaust. This auger-like resonator was an attempt to eliminate the cab drone these trucks emit.”
With no other changes other than the removal of the resonator and replacing it with a freer-flowing muffler, Emanual’s truck picked up 120 horsepower. Unlocking that kind of power with a single part removal is pretty wild, to be honest. “Although the cab drone can be annoying, I don’t see it being worth sacrificing the 120 available horsepower,” Miller said. “On trucks with lower power, this may not be near as critical but high-horsepower trucks beware.”