A heavy trailer places a great deal of stress on any tow vehicle’s brakes. Towing large trailers in mountainous regions, along twisting, diving highways or in heavy stop-and-go traffic taxes brake systems even more. The combination of repeated applications of the brake pedal under loaded conditions results in a more frequent need to replace brake parts such as pads, discs, shoes and drums. And on top of all that, there’s the basic towing safety issue of brake fade when decsending long, steep grades.
Most of the modern diesel engines in pickup trucks are now equipped with factory exhaust braking systems to help slow the truck down by utilizing the diesel’s turbo and exhaust systems. As an example, the General Motors Duramax diesel engine utilizes a variable-vane turbo to help do that braking work.
But if you want even greater exhaust braking from your General Motors heavy duty pickup — and desire more physical control over that braking — BD Diesel Performance has developed an adjustable electronic controller that greatly enhances the engine-braking power of the Duramax turbo.
BD’s Variable Vane Brake (VVB), which is literally a plug-and-drive installation, works with the turbocharger used in the 2004.5 and newer Duramax engines.
The BD VVB kit comes with a “brain box” pre-wired with a “T” wiring harness that plugs in to the mass of sensor wires leading from the engine to the on-board computer. That allows the BD computer to make changes that affect the engine, turbo and transmission functions to maximize exhaust braking and downshifts. And for 2006-and-newer applications the VVB kit offers a warm-up feature that will close the vanes at idle until engine temperature reaches a pre-set level.
It’s really simple to install and works by developing exhaust backpressure in the engine’s combustion chamber, which creates resistance against the piston from reaching top dead center. In the most basic of terms, BD Diesel’s kit helps to maximize the engine’s compression braking.
BD’s technology electronically closes off the Duramax’s turbo vanes, which creates up to 130 retarding horsepower to shoulder some of the braking responsibility off of the Silverado/Sierra HD pickup’s brake pads and rotors. Best yet, The VVB system works in “Normal,” “Manual Shift” and “Tow/Haul” driving transmission modes.
This added exhaust-braking force, along with more aggressive downshifts that are also part of the VVB programming, really helps slow down trucks that are pulling heavy trailers or carrying large slide-in campers.
The VVB rotary switch has four different positions the driver can select depending on need:
Off: The engine works in stock mode.
Level/Position 1: Closes the turbo vanes only when the throttle is released.
Level/Position 2: Closes the turbo vanes and causes a moderate down shift when the throttle is released.
Level/Position 3: Closes the turbo vanes and causes a more aggressive downshift when throttle is released.
I drove a 2009 Silverado 3500 HD with the BD VVB system installed while towing a gooseneck trailer that tipped that scales at close to 16,500 pounds. The difference in braking and brake use was like night and day. When the VVB dial was in the #3 position, the truck slowed down the combo I was driving on a fairly steep section of highway as if I were applying the brakes fairly aggressively.
Driving in city traffic had the same results, effectively eliminating the need to touch the brake pedal during normal traffic slow-downs.
If you want that added level of braking power in your diesel-powered GM HD truck during your towing travels, consider beefing up that turbo to help take the load off your rig’s braking system. BD’s $695 VVB kit will pay for itself in short order. In addition, BD Diesel Performance is developing a kit for Ford diesel engines.
Source: BD Diesel Performance, 800-887-5030, www.dieselperformance.com