The engineering wizards at Toyota Racing Development (TRD) are best known for producing the company’s SCORE off-road race trucks, but they also develop products for the showroom. For 2017, TRD will introduce the Toyota Tacoma TRD Pro based on the midsize pickup introduced last year.
“Our customers were looking for better torque buildup in the steering system and improved isolation off-road,” explained Jakin Wilson of TRD’s design engineering group. “On dirt roads, we wanted to decrease shock going over large dips.”
Although TRD sources suspension components from other manufacturers such as FOX, it tunes all components themselves. TRD did multiple tunings of the FOX 2.5 internal bypass shocks on the Tacoma TRD Pro at Toyota’s Arizona Proving Grounds. “This is an iterative process, explained TRD’s Brent Craig. “There’s an art to sourcing the components from different suppliers and mixing and matching them to achieve the desired results.”
The new Tacoma takes off-road performance to the next level without compromising ride and handling on paved roads. “We still have to strike a balance between on and off-road performance,” said Craig. “We chose the Kevlar reinforced Goodyear Wrangler tires because while there might be better choices for exclusive off-road use, the Wranglers don’t compromise in areas such as road noise when the vehicle is driven on pavement.”
Additional modifications to the suspension include TRD-tuned front springs with a one-inch lift and a TRD tuned rear suspension with progressive-rate off-road leaf spring.
Crawl Control
The Tacoma is one of several Toyotas employing a proprietary crawl control system that enables the driver to control the speed on extreme ascents and descents. We experienced this system from behind the wheel: on grades as steep as 40 degrees and were amazed with the control it gives the driver.
Engineer Mike Donick of Toyota’s Arizona Proving Grounds explained that the system eliminates the vacuum booster found in traditional braking systems and replaces it with an Integrated Hydraulic Booster (HB-Ci) consisting of an accumulator and hydraulic pump. The hydraulic reservoir can build up pressure very quickly: 10 times faster than traditional brakes. As a result, there are no momentary lapses in system function: a crucial difference between Toyota’s system and competitive units.
The crawl control unit located near the firewall eliminates the need for separate antilock braking and stability control mechanisms. A microprocessor utilizes inputs from an accelerometer, yaw rate sensor, steering angle sensor and brake pressure.
When the driver engages crawl control in low gear range utilizing a rotary dial, the system controls both engine and brake torque. The idea is to create a steady flow of power over uneven surfaces such as big boulders so the suspension doesn’t bottom out coming off a precipice.
Although the system works without touching the accelerator or brakes, the driver can use the brake pedal to slow the vehicle down. As a matter of safety, hitting the brakes will not disengage the system.
Underbody Protection and Special Badging
Aluminum skid plates protect sensitive chassis components under the Tacoma TRD Pro cab. Other features unique to the model include 16-inch black wheels, Rigid Industries LED fog lamps, LED daytime running lamps, and special badging.
Inside the trucks get unique black leather seating and a TRD shift knob. A GoPro mount on the windshield allows you to capture all the off-roading action.
The Tacoma TRD Pro rolls out this fall.
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