Slow the Load

Diesel World July 2012

Adding Load Control With a Banks SpeedBrake (on a ‘07.5 GMC Sierra 2500 HD).

Using a diesel truck as a tow rig is one of the reasons you bought it in the first place. Those towing duties include work and play.

A case in point is Jereme Miltier, at RPM Offroad, in Bristol, Tennessee. He frequently uses his ‘07.5 GMC Sierra 2500 HD to tow trail rigs or even one of the shop’s many championship-winning desert race trucks or buggies. The truck has a factory-installed electronic brake controller, but additional help is always welcome in the braking department – especially when towing 15,000-plus pounds of race truck and trailer up and down steep mountain grades.

To enhance the towing capability and safety of his LMM Duramax-powered GMC, Miltier opted to install the Banks SpeedBrake and iQ interface (see product image). He invited us up to the shop, just a few miles down the road from the famous Bristol Motor Speedway, to follow along with the installation and testing of the system.

The SpeedBrake from Banks is considered one of the best exhaust brakes on the market for newer Ford and GM diesel trucks with variable geometry turbos. When paired with the Banks iQ interface, the iQ not only controls the functions and settings of the SpeedBrake, it also has five virtual gauge fields that can be displayed in digital or analog formats to monitor vital and truck stats.

On the ‘07.5 LMM Duramax engine, the display can show boost, SpeedBrake application percentage, engine load, fuel level, intake pressure, intake temperature, rpm, speed throttle percentage, gear, grade, fuel pressure, elevation, DPF regeneration status, direction, barometric pressure, ambient temperature, instant economy, soot, time transmission temp and engine temp.

The iQ can also function as an OBD-II scan tool that will allow you to read and reset trouble codes from your truck. On top of that, Banks has included an economy display that helps you keep track of your fuel expenses and efficiency, as well as trip calculations. It is also battery powered and can be used outside the truck to play games, listen to music, view pictures, watch movies or even view Office documents with its Windows CE-based software.

With multiple operation modes and settings, the driver can tailor the SpeedBrake engine braking to suit his driving style and vehicle load. In Manual mode, the system can be set for low, medium or high braking force that can be activated whenever the driver is off the throttle or when the vehicle brakes are applied. When the system is put in the Auto mode, the driver can set the desired descent speed in 1-or 5-mph increments – much like a cruise control for downhill use. The Auto mode can also be set to activate when off the throttle or when the brakes are applied.

Conventional exhaust brake systems rely on a butterfly valve or similar restriction in the exhaust system to create backpressure on the engine and provide additional engine braking. The engineers at Banks Power used comparable methods with the SpeedBrake but took it a very big step further.

It uses a harness that integrates with the factory ECU to control the variable geometry turbocharger to act as an exhaust brake. But beyond that, it also controls the torque converter and transmission. By locking the torque converter and downshifting the transmission, the SpeedBrake delivers improved braking performance, as compared to a traditional exhaust brake.

The Speed Brake is available for ‘04.5 – ’10 GM Duramax 6.6L diesel trucks, ’03 – ’07 6.0L Ford Power Stroke diesel trucks and ’08 – ’10 6.4L Power Stroke diesel trucks. To take full advantage of the SpeedBrake capabilities, you’ll want to spring for the optional 5-inch touch screen iQ interface controller, but the system can also be installed with a rotary switch control that offers the low-, medium- and high-strength braking options, as well as foot brake operation; but it does not offer the Auto mode speed setting capability.

Operating the SpeedBrake system is very simple, and while the iQ has an astounding amount of capabilities, it is still easy to use. The low setting is best used for an unloaded truck or when hauling light loads, while the medium setting is good for moderately loaded trucks. The high setting works best when the truck is heavily loaded. Of course, the Auto mode and speed setting for downhill operate just like a cruise control and will probably be the most-used mode when towing heavy loads.

The SpeedBrake system comes with everything needed to install it in your truck and could easily be installed by most DIYers in probably under two hours. RPM Offroad installation technician Michael Powell installed the system on Miltier’s GMC in an hour and 15 minutes (this included the typical photography slow-downs involved with documenting the installation for an article).

It is much easier to install than a standard exhaust brake. It offers plug-and-play installation using connectors that mate to the factory connectors in your truck with no modifications to your exhaust system or splicing into your truck’s wiring harness.

If you own a late-model diesel with a VVT computer-controlled turbo and are looking for a little more “Whoa!” power heading downhill with a load, the Banks SpeedBrake is worth checking out.

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