Thanks to the diesel aftermarket, many aspects of our trucks can be improved tenfold to help us tow easier. We can simply plug in a programmer, bolt on an air intake, and install an exhaust system-which all improve acceleration performance. But what about the other side of the coin: braking?While most companies are concerned only with getting your load up and moving quicker, Gale Banks Engineering is on both sides of the fence. Its latest development, the SpeedBrake, is the most technologically advanced exhaust braking system in the aftermarket today. It was designed to allow your LLY, LBZ, or LMM Duramax ('041/2 to current) to manage the load you've got in tow with the utmost safety in mind.
Exhaust Brakes Of The Past
Traditional exhaust brakes featured butterfly valves in the exhaust system that would block or restrict exhaust flow in order to slow a truck and trailer down. Peter Treydte, Banks' engineering test group manager, told us that the problem with this is it applies a lot of pressure on the top of the engine's pistons during the exhaust stroke, which has a chain reaction effect, where even the crankshaft is slowed (creating more of an engine-braking scenario than exhaust braking). Furthermore, conventional exhaust brakes required labor-intensive installs, which consisted of cutting and welding on the exhaust system, followed by wiring. The SpeedBrake, on the other hand, installs easily with a few simple connections under the hood, has an extensive electronic management system, and comes with a PowerPDA for monitoring all of your truck's braking and operating functions.
Courtesy of Banks' touch screen...
Courtesy of Banks' touch screen PowerPDA, any SpeedBrake feature you want to experience is at your fingertips. The PowerPDA in our test looked similar to the one pictured. We could see which mode the SpeedBrake was in (Speed Control mode with a 35-mph target speed is shown), what braking strength was being applied (60 percent is shown because the target speed was already obtained), transmission temperature, engine coolant temperature, and gear indication.
According to Banks, the SpeedBrake is all about taking the current technology available on the market and capitalizing on it. For example, while the main intention behind variable geometry turbo technology was to increase acceleration performance (by varying the volume of the exhaust housing and making the turbo act like a smaller unit for quicker spooling), Banks realized that varying drive pressure on the turbine wheel could also be used to create backpressure, thus slowing down a vehicle. Along with using the VGT to aid in stopping, the SpeedBrake controller allows the Allison transmission to downshift more aggressively than stock and also controls torque converter lockup.Different Operating Levels
Three basic modes are available on the SpeedBrake. In the Off mode the unit provides no help, and your only method of stopping is by applying the brake pedal and allowing the Allison to downshift in its factory Tow/Haul setting. In the On mode, three brake settings are available: high strength for heavy loads, medium strength for intermediate loads, and low strength for little-to-no load behind the truck. The SpeedBrake can be set up to activate any time the foot brake pedal is applied.
The last operating mode is called Speed Control, where you can set a target speed for hill-descent situations. Target speed can be adjusted incrementally between 25 to 75 mph, and three pre-set options can be used or customized to each driver's specific needs.