The Walker Mega-Flow NoiseBraker muffler, made by Tenneco, is a low-cost, direct retrofit for class 7 and 8 vehicles, said to be capable of reducing back pressure and quieting the engine brake to legal limits.

It features a straight-through, ultra-high flow design to reduce engine back pressure by as much as 60%. The company says it improves engine efficiency as compared to traditional heavy-duty muffler designs that channel exhaust flow through a series of baffles and restrictor tubes.

Available for single- and dual-exhaust applications, the NoiseBraker is claimed to be 2 to 4 decibels (dB) quieter than the industry’s best OE mufflers under engine-brake-induced deceleration. It uses fiberglass ‘roving’ technology and dual concentric tuners to quiet engine-brake noise without affecting brake performance.

Each Mega-Flow NoiseBraker muffler is covered by a limited lifetime warranty and a 90-day “Safe & Sound Guarantee” money-back trial offer (some restrictions apply; see www.walkerheavyduty.com for details).