Flight of the Raptor: Torture Testing in the Desert
We help Ford's SVT engineering team torture test its next desert-storming F-150
The driveway's hard to spot in the predawn gloom, just a gravel track off a dark desert highway, curling around behind some strategically planted trees. Our BMW M3 long-termer crunches into a small parking lot bordered by small sheds and littered with pickups and trailers. An old tractor rests quietly in one corner. Then we notice the bright-red Hughes MD500 helicopter. And the three gleaming Ford F-150 Raptor SuperCabs lined up next to it. And then we spot a couple of hulking, oddly indistinct shapes -- black-bagged bad-boys standing high and wide: prototype Raptor SuperCrews, still under wraps. This is where Ford's Baja-racer inspired F-150s learn how to fly.
We're here to join the Ford SVT engineering team for the last leg of a 1000-mile durability test, the final step before the Raptor SuperCrew is signed off for production. This promises to be no ordinary durability run: Basically, we're going desert racing.
Other than the fact it rolls on the 144.4-inch wheelbase common to Ford's other 5.5-foot bed crew cab F-150s, I can only guess what the Raptor SuperCrew actually looks like, because every inch of the exterior is covered in heavy black-plastic camouflage. The SVT guys have even built a false canopy over the bed to make it look like a full-size SUV. But there's no disguising the 10 inches or so of ground clearance and the 17-inch alloy wheels shod with meaty 315/70 BFGoodrich tires. Or the gleam of the long-travel Fox Racing Shox internal bypass dampers in the wheelwells.
Inside, there's a slightly revised dash with a cool new feature I can't tell you about yet because it's part of the F-150's 2011 model-year tweaks. And there are a rollcage and five-point harness safety belts. SVT vehicle dynamics engineer Matt Johnson, who also worked on the chassis tune for the 2011 Shelby GT500 and races a spec-series Miata on the weekend, slides behind the wheel, helmet in hand and a HANS-type helmet restraint system on his shoulders. I climb into the passenger seat and check out the rally-style GPS navigation device in front of me. The 66-mile loop has been programmed into the system, with yellow and red crosses marking the hazards according to their severity. My job -- apart from hanging on and not barfing into my full-face helmet -- is to make sure I call them out.
We strap in and helmet up, and Johnson twists the ignition key. The engine rumbles into life, and immediately I notice a meaner, harder edge to the exhaust note, tuned by NVH development engineer Hether Fedullo. Under hood is Ford's all-new 6.2-liter V-8 (see sidebar), which in Raptor tune develops 411 horsepower and 434 pound-feet of torque-healthy increases of 91 horsepower and 44 pound-feet over the 5.4-liter V-8 the Raptor SuperCab launched with last year. This will be the standard engine in the Raptor SuperCrew and a $3000 option on the 133-inch-wheelbase Raptor SuperCab.
We rumble out the drive and onto the highway. Barely five minutes later, Johnson swings off the blacktop and onto a stony desert road. He stops and selects off-road mode, which alters the rate at which the throttle responds to gas pedal inputs and also recalibrates the ABS for loose surfaces. Johnson elects to keep the Raptor in 2WD, but pulls out the button to lock the rear diff. Then he selects sport mode, which reprograms the stability-control system to allow more freedom to slide the truck. "You can turn it all the way off," he says, "but you don't need to -- it stays out of the driver's way." The system monitors driver inputs, principally steering-wheel motions and brake applications, and steps in only when it notes a change in the pattern. "We figured if we did a bad job, people would find a way of disabling it." And with that, he punches the gas.
The 6.2 growls and the big Raptor quickly gathers speed. Though fast and open, the road is narrow and stony, jinking left and right in places. Hungry-looking boulders dot the verges. Johnson's relaxed, but on it, deft gentle inputs on the steering wheel, eyes scanning the road ahead for hazards that may not have been there yesterday: "One of the things we had to learn is there is a randomness to the desert." I glance down at the readout on the GPS screen in front of me. We just touched 99 mph.
"We thought the longer wheelbase would degrade the off-road performance, but that's not the case," says Johnson of the SuperCrew Raptor. The SVT team specified a quicker steering ratio from the get-go, but the real key to making the Supercrew work off-road, says Johnson, has been to dial more low to mid-compression damping into the shocks. "That has speeded up the transitions," Johnson says. "The short-wheelbase truck feels nimble and a bit on edge. The long wheelbase is still nimble, but it's calmer, more relaxed. Yaw, pitch, and roll motions are slower."
The first 20 miles or so are fast and rough. The rest of the loop is slower, and really rough. We're pounding across whoops and washouts, and the way the suspension soaks up everything the desert throws at it is truly astounding. About halfway through the loop, Johnson pulls over. It's my turn to drive. I'm not allowed to say anything about the SuperCrew itself, as it's still several months away from launch. What I can say, however, is this: After a couple miles, I can scarcely believe I can horse a rig this big this fast through country this rough. Time and again the big truck simply shrugs off impacts that should have suspension parts popping through the bodywork.
The goal is to complete each loop in about 90 minutes, and if an average of 40 mph or so sounds slow, consider that, on one section, nicknamed the Pole Line, the suspension will go from full compression to full rebound -- that's 11.4 inches of travel up front and 12.2 at the rear -- non-stop for up to eight miles, the shock pistons reaching velocities of 160 inch/second. I'm not going to drive the Pole Line -- "It's just not fun," says Johnson. So after half an hour or so of pounding the Raptor SuperCrew harder than I've ever pounded any vehicle in my life, I pull over and hand it back.
The Raptors are built using the biggest brakes and strongest halfshafts in the F-150 parts bin, along with the heavy-duty rear axle. SVT has stiffened the engine and transmission mounts 45 percent and crafted trick new aluminum control arms for the front suspension. Those expensive Fox Racing Shox dampers on each corner are the Raptor's secret sauce, however (and they're expensive-SVT's director of basic design and performance vehicles, Hermann Salenbauch, an ebullient German engineer whose CV includes stints at BMW and Rover, says when he presented the Raptor program's costings to Ford's product development brass, one of them saw the piece cost for the shocks and exclaimed: "I could get half a V-8 for that!"). But making the Raptor dance across the desert has taken a lot more than simply bolting on a set of desert racing dampers.
Working to supply an original equipment part was a learning experience, for both Ford, and aftermarket shock manufacturer Fox Racing Shox. The SVT team was impressed with the speed with which Fox could make design changes: "It normally takes weeks for our suppliers to make a change to a part," says vehicle dynamics engineer and lead test driver Gene Martindale. "These guys would do it overnight." And the Fox folks couldn't believe the improvements possible using the skills and tools available to an automaker's development team: "We had the truck about two-thirds as good as where we are now, and they thought it couldn't get any better," says Martindale, who drove a Raptor prototype in the grueling Baja 1000 as part of the truck's development program.
While Martindale and I spend the rest of the day hammering a production-ready 6.2-liter powered Raptor SuperCab along the desert trails, the rest of the team gets to work putting more miles on the two SuperCrew prototypes. The grand finale to each loop is a couple passes over a specially constructed tabletop jump right next to the secret Raptor lair. I stand and watch as 6000 pounds plus of pickup truck gets airborne-and lands with remarkable grace.
Raptors can fly, all right. And now I know how.
Ford's New V-8
The 6.2 is the engine the Raptor was always meant to have--the decision to launch with a tuned 5.4-liter Triton under the hood was made when the two development programs got slightly out of phase.
Built at Ford's Romeo engine plant, the new 6.2 is a conventional iron-block, aluminum-head V-8 with single overhead camshafts, variable camshaft timing, and two valves -- and two spark plugs -- per cylinder. The crank is secured by four bolt main bearing caps, cross-bolted for extra durability. Forged steel connecting rods are standard, as are lightweight magnesium cam covers and a composite intake manifold.
The base engine will debut in the 2011 Super Duty with 385 horsepower and 405 pound-feet of torque. A unique cam profile means the engine will pump out 411 horsepower at 5500 rpm and 434 pound-feet at 4500 rpm in Raptor trim.
The oversquare configuration (bore is 4.02 inchdes and stroke 3.74 inches) means the 6.2 revs harder than the long stroke Triton. Both power and torque peaks occur further up the rev band in the bigger engine. The 6.2 sounds different too -- leaner and meaner thanks, in part, to its different firing order.