The state-of-the-art semi-active Live Valve 3.1 suspension on the new 2021 Ford F-150 Raptor needed to provide a wider range of damping support and control to provide the best performance over any terrain. How did FOX do it?
Increasing Capability
To make this possible, FOX engineering needed to make a number of changes to the shocks. They started by doubling the amount of force the Live Valve adjuster could control compared to the previous generation.
But by increasing the amount of force the Live Valve adjuster could apply by two-fold, the internal pressures within the shock also increased. So, FOX also increased the diameter of the shock bodies from 3.0 to 3.1 inches, enlarging the walls of the shock body to withstand the higher internal pressures.
Read "New 2021 Ford Raptor: Experiencing Aggressive Control And Stability With 3.1 Live Valve"
These two changes, among others, allow for twice the damping range of the previous generation Raptor and peak at over 6,000 lbs. of damping support per shock.
What About Comfort?
FOX also knew it couldn’t give up anything in the category of comfort. So, it developed proprietary PTFE-infused ultra-low friction 5WT that offers a 50% reduction in assembled shock friction in the oil alone.
What does that mean? It’s like having oil for your shocks made for non-stick frying pans: silky smooth.
Now, let’s dive into exactly how the shocks’ internal bypass design and the upgraded Live Valve technology control double the damping support of the previous generation.
Internal Bypass
In general, the amount of damping support provided depends on the position of the shock as it moves.
When the shock is at the beginning of its travel, it compresses with very little resistance. This area is called the “ride zone.”
The oil inside the shock moves in a circular flow: up the inner body, through shimmed bypass ports, down between the inner and outer body, then back through refill holes. The oil bypasses the main piston so the shock can move with ease and provide comfort over light terrain.
Now as the terrain becomes more aggressive, the shock compresses further into the travel. It continues step-by-step past each additional bypass port — which progressively forces more oil to flow through the main piston assembly. This increases resistance and slows down the shock, providing you a broad range of support.
And finally, at the end of the travel, the shock compresses into the area called the “Bottom-Out Zone.” All oil is forced to flow through the main piston assembly, which provides the most resistance and slows down the shock. This provides the firmest support — protecting you from bottoming-out over the roughest terrain, like whoops and jumps.
Live Valve
While these broad internal bypass zones determine the “base level” of damping support, it’s the Live Valve technology that allows more range and precise adjustments as you drive.
The race-proven Live Valve system uses sensors to gather real-time data 500 times a second. Then, the Raptor’s new algorithm interprets data and creates a predictive model based on your current driving style and terrain trajectory.
This means if Live Valve determines a shock should move faster and provide more comfort in the moment ahead, it’ll decrease preload on the spring behind the needle, which will open the valve.
If it determines a shock should move slower and provide more support in the next moment, it’ll increase preload on the spring behind the needle proportional to the amount of support needed.
If the terrain becomes even more aggressive, these adjustments to the needle work in tandem with the boost valve — which uses hydraulic pressure to progressively increase support and protect you from bottoming out.
Conclusion
Why does this matter? FOX increased the shock body diameter and internals from the previous design, allowing you to drive full tilt off-road with increased handling performance while significantly improving control over bigger obstacles. With a dynamic range of twice the prior valve design, the new electronic valve architecture shrugs off significantly larger hits with the feeling of bottomless travel and smooths out the most rutted out teeth-rattling washboards.
Like what you see? Check out all the FOX Academy videos for powered vehicles and mountain bikes here.
