http://news.pickuptrucks.com/2008/11/the-raptor-has.html
Suspension
With the running conditions and test approach settled, the next area of concern was the suspension. If street performance is all about controlled horsepower, then offroad performance is all about useable suspension travel.
The heart of the Raptor is its long-travel suspension. To create it, SVT teamed up with Fox Racing, a leading designer and manufacturer of high-performance shock absorbers and racing suspensions. Up until now, long-travel suspensions have only been available through the aftermarket as expensive retrofits of stock pickups.
Fox created all-new internal bypass shocks especially for the Raptor. They’re as radically different from the stock F-150 shocks as a Ford Shelby GT500KR Mustang’s supercharged 5.4-liter V-8 is different from the base Mustang’s 4.0-liter V-6.
The packaging of the blue and silver shock absorbers is impressive; they make standard truck shocks look about as sophisticated as the absorbers on a Flintstones-mobile.
The independent front suspension’s shocks are coilovers, paired with unique-to-the-Raptor single-stage spirals. They have 11.2 inches of travel, versus 8.5 inches of travel in a base F-150. The extra 2.7 inches are needed to manage the high-impact forces sent through the Raptor after sticking a jump. The rear shocks are piggyback reservoirs paired with heavy-duty rear leaf springs. They keep the same 13.5 inches of travel as a base truck.
The 2.5-inch Fox shocks have larger diameters than both the F-150’s base shocks and the offroad FX4 F-150’s Tokico shocks. The extra size is needed to house the 47-mm (1.85-inch) pistons and internal bypass valves. They also hold the extra oil needed to cool the shocks and prevent fade from the extreme heat generated during rapid compression and rebound cycles crossing rough desert terrain at high speeds.
Unlike standard monotube shocks offered as original equipment in other factory-built off-roaders, bypass shocks provide tunable, progressive stiffening throughout the shock stroke by precisely controlling the flow of oil via secondary tubes, minimizing pockets of uneven hydraulic flow from heat or unequal pressure.
Most aftermarket bypass shocks use an external bypass setup, placing oil routing tubes with adjustable check valves on the exterior of the shock. The valves allow users to easily dial in different damping settings by increasing or limiting the flow of oil around the shock, depending on the environment, application and vehicle type.
Fox Racing’s internal bypass technology is slick and maintenance-free. Instead of placing the oil routers outside the shocks, Fox sealed them inside the main tube so that they can’t be adjusted. The valves have been replaced with very small gates, precisely placed for optimal damping in all conditions, based on thousands of hours of off-road Raptor driving. Hardcore off-roaders might not like this setup, but it solves several potential issues both for Ford and for less-obsessive desert-running enthusiasts. There are no external bypass tubes to be damaged by the front coilover springs rubbing against them or by offroad debris striking them; there are no worries about check-valve durability; and Ford doesn’t have to train consumers and dealers on how to tune the shocks.
Like every Ford vehicle, the shocks also had to meet Ford’s durability standards.
“They’ve been engineered to meet Ford's internal durability standards, 10 years or 150,000 miles, without being rebuilt or replaced,” Hameedi said. “They also had to start and finish 1,000 miles on the [Borrego] durability loop with no more than 30 percent degradation. Even in the toughest testing, oil temperatures [in the shocks] stayed around 250 degrees.”
Other suspension changes include unique upper and lower control arms with the letters “SVT” prominently cast into the lower wishbones, new tie rods, increased diameter half shafts, beefed-up ball joints and high-strength steel from the Super Duty, used to shore up the rear shock brackets. Front and rear bumpstop shock microcellular jounce bumpers provide additional impact absorption when the Raptor bottoms out.
Baja racing wasn’t the only inspiration SVT found in Mexico. To handle the high load forces in the rear axle, the Raptor’s rear axle shares heavy-gauge axle tubes with Mexican-spec F-150s, which tend to be driven overloaded more frequently than U.S. versions are. The extra mass in the back axle adds to truck's unsprung weight, which requires additional shock and leaf spring tuning so the rear end won't kick up after landing hard.
The rest of the F-150 platform was already strong enough for going off-road at speed.
“There wasn’t a need to strengthen the Raptor’s frame,” Baldori said. “It’s already bulletproof.”
I just watched the video. That's Mike from PickupTrucks.com, which is a site we just bought over the summer. I was just talking to him at my desk last week and didn't even know he and StreetFire did a video. Sweet.
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