I've only driven two pickups in my life. That's how much I hate them. Other than the occasional moving transportation, I want nothing to do with them. Even domestic burnout machines wearing SVT or SRT badges don't do it for me (though I must admit I haven't driven either). Physics and trucks just don't mix. I regarded TRD's 400bhp prototype X-Runner with similar disinterest, until I heard it turned handling numbers that are supposedly better than a 350Z. So it was off to the local racetrack to prove Newton wrong.
At last year's annual SEMA show, the newly-reorganized TRD unveiled a fire-breathing concept of the Toyota X-Runner, tagged the TRD X-Runner. Built on the same chassis as the X-Runner, but with a supercharged version of the 1GR-FE four-liter V6, this truck was TRD's way of showing off its engineering expertise, as well as providing Toyota with a temporary 'hero' vehicle until a long-awaited Supra replacement comes.
In addition to this operational show truck, TRD and the Toyota Technical Center (TTC) engineers also built a blue-duct-tape-and-aluminum mule with the same engine, but sporting further chassis, steering and aero-dynamic refinements to make an even more brutish track destroyer.
Augmenting the heart of the TRD X-Runner is a mid-sized Eaton M90 positive displacement supercharger, stuffed between the banks of the stock displacement V6. Internally, 9.2:1 compression custom CP pistons, Carrillo rods and minor machining to the stock crank are all that separate the 400bhp bottom from the stock 10.5:1 Tundra/Tacoma unit. Even the heads and gaskets are kept stock (with the exception of some minor port matching). TRD also custom-ground 214.5- and 212.5-degree duration intake and exhaust cams featuring more lift on the intake side and less on the exhaust. To accommodate this, the lower manifold beneath the supercharger was replaced with a unit that directly bolts to the blower and also features trumpets tuned for boosted flow.
Also thrown in is an 80mm throttle body from a big Toyota V8, a pair of tubular three-into-one headers (that still include high-flow close-coupled cats), a big beefy exhaust, and a top-fed panel intake filter breathing through the stock X-Runner hood scoop. Fuel and engine management are controlled through multiple custom Toyota ECUs, piggybacked to run the six 410cc/min injectors in the stock manifold bosses, two additional injectors (prior to the compressor), e-throttle, plus enough data acquisition, communications and signal processing channels to run a Mars Rover.
The big headache with any Roots-type blower is cooling. Mechanically compressing 400bhp-worth of air generates a lot of heat. Air-to-air intercooling is not practical, so TRD has deployed a massive liquid-to-air intercooler system with added pumps, lines, reservoirs, and a massive heat exchanger stuffed into the grille to help the system cope-which it does even under summer conditions at the track.
It's not the big power numbers, though, that brought out the Curious George in me. It's how much Toyota's engineers were able to accomplish with just minor tweaks to the chassis. From the outset, TRD had its crosshairs set on beating the Nissan 350Z in handling. With only the addition of stiffer bushings and anti-roll bars, wheels and tires, and a pre-loaded gear-type limited-slip differential, TRD's X-Runner is able to turn g numbers comparable to-or better than-a stock Supra or 350Z. And it's only lowered less than one inch, with stock spring rates on revalved dampers.
Even with such handling prowess, it still drives like a truck. The huge torque, 6000rpm rev limit, and a center of gravity high enough to limbo under are constant reminders of the X-Runner's hauling heritage while tearing through a 100mph sweeper. Every driving instinct is in full conflict as you turn the quick-ratio steering, strapped into a bucket Recaro with a roll hoop over your head while sitting several feet higher than any sport compact. It's still not my cup of tea, but it's the closest any truck has come. Toyota and TRD have pulled off an amazing feat.
For the closet truck-loving reader, TRD won't be offering the 400bhp version of the supercharger kit, but will offer the same blower tuned to 310 ponies on pump gas. Everything else (suspension and cosmetics) is still in the works, but as far as I can tell, the potential is there.
TRD Tacoma X-RunnerEnginEngine code: 1GR-FEType: 3956cc V6, iron block, aluminum heads, supercharged and intercooledInternal modifications: CP 9.2:1 CR pistons, Carrillo rods, balanced stock crankshaftExternal modifications: TRD 214.5 intake and 212.5 exhaust cams, TRD/Eaton M90 supercharger, TRD lower intake manifold, TRD liquid-to-air intercooler and heat exchanger, TRD air box, 80mm 2UZ-FE throttle body, custom three-into-one tubular exhaust headers and exhaust, oil-to-water oil coolerEngine management modifications: Multiple custom-programmed Toyota ECUs, 6x410 cc/min injectors and 2x 410 cc/min pre-compressor injectors, Walbro 200lph fuel pump, custom fuel cel
DrivetrainLayout: Longitudinal front engine, rear-wheel driveDrivetrain modifications: TRD quick shifter, modified stock clutch, lightened billet steel flywheel, 1330 Spicer u-joints, Currie Enterprises rear axle, Strange Engineering aluminum third member with 9-in. ring gear, pre-loaded DPI Black Gold Track torque-sensing differential, 3.55:1 final drive
SuspensionFront: Stock rate lowering springs, revalved struts, hard rubber bushings, 35mm anti-roll barRear: Stock rate leaf springs, revalved shocks, hard rubber bushings, 28.6mm anti-roll bar
BrakesFront: TRD 14-inch vented floating rotors with four-piston fixed calipers, Pagid Orange pads, TRD stainless steel brake linesRear: Prototype TRD 14-inch vented floating rotors with two-piston fixed calipers, Pagid Orange pads, TRD stainless steel brake lines
ExternalWheels: 20 x 9 (f), 20 x 10 (r) forged aluminumTires: Pirelli P Zero Rosso, 275/40R20 (f) 315/35R20 (r)Body: TRD bodykit, cab mounted vortex generators, tonneau cover with fences, front and rear underchassis diffusersInterior: Recaro seats, six-point roll bar, 360mm steering wheel
| STOCK PERFORMANCE (AS TESTED BY TOYOTA) |
| Acceleration | TRD X-Runner | Stock X-Runner |
| Quarter-mile time: | 14.54 secs. | 16.27 secs. |
| Quarter-mile speed: | 102.3mph | 89.6mph |
| 0-60mph: | 6.06 secs. | 7.88 secs. |
| Handling |
| Lateral grip |
| (200-ft skidpad): | 0.99g | 0.97g |
| Braking distance | | |
| 60mph-0: | 137 ft | 115 ft |