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Fox
Ask the Experts - Get Tuned
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Budd Stanley
Ask the Experts - Get Tuned
The Fox DSC adjuster, which allows for both high and low-speed adjustments.
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Budd Stanley
Ask the Experts - Get Tuned
Some shocks require tools for adjustments.
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Budd Stanley
Ask the Experts - Get Tuned
Fox’s DSC adjusters compliment shocks already tuned to specific vehicles thanks to a shimmed bypass valve, seen in the cutaway.
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Budd Stanley
Ask the Experts - Get Tuned
Once you’ve mastered adjustable shocks and start building competition vehicles, adjustable oil bypass valves will be the next, and very expensive step.
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Budd Stanley
Ask the Experts - Get Tuned
Interview & photos by Budd Stanley, additional photos by Fox
Shock guru, Wayne Isrealsen, teaches the basics of shock adjustment
You’ve built a capable 4WD that has accomplished your primary goals when starting out in the off-roading world. With seat time and experience, your skills have increased and you’ve learned to find the limitations of your vehicle. For some, this may be as far as you want to go, but for most, the urge to increase the performance and capabilities of our vehicles is usually an addictive and very expensive drug we just can’t shake.
Much like the first round of off-road modifications, most will look to the suspension first on round two. This is a good thing, because if your tires aren’t touching the ground, they can’t do their job. The most common modification is to swap those off-road tuned monotube shocks for a nice shiny set of remote reservoir shocks with dampening adjustability.
Putting high priced adjustable shocks on your rig is a waste of money, if you don’t know how to tune them properly. Therefore, we went straight to the top man at Fox Racing to get the low down on shock tuning. Wayne Isrealsen is a legend when it comes to tuning shocks for off-road-based motorsports. He has gained an expert level of knowledge of vehicle set-up for events such as the King of the Hammers, and was recently named the Off-Road Race Program Manager for Fox. We were able to find a couple free minutes in his busy day to sit down and talk about the basics of shock adjustment.
4WD: For the completely uninitiated, can you describe basics of shocks?
Wayne: The shocks job is to dampen the movement of the spring - which holds the vehicle up - in both compression and rebound. In other words, it converts the kinetic energy into heat through oil restriction. The valves in the shock are designed to become more restrictive as more oil moves through them, therefore the faster the shock moves, the more restricted the oil flow will become.
4WD: Can you describe what softening and firming up shock dampening does? How does that increase comfort or performance?
Wayne: If the suspension is too soft and not creating enough force you run the risk of your shocks bottoming out abruptly. So you would increase compression force, firming it up will keep the suspension from using up all its travel to quickly and will also help from bottoming out. Now conversely, if the suspension is just too harsh or beating you up too much, or it’s not using up all the shocks travel and not bottoming hard, that’s when you would start adjusting to the softer side.
4WD: Who should be looking to put an adjustable suspension on their vehicle?
Wayne: For our DSC (Dual Speed Compression) system, we’re talking about someone who wants dual use for their vehicle. These are people who are still driving their 4WD daily, but after they pick the kids up from soccer practice, and want to have some fun on the trails, they can make a couple of adjustments and change the attitude and comfort levels of their 4WD. For more complex shocks with four-way adjustments and adjustable shims and valving, then we are getting into the dedicated wheeler and competition vehicles.
4WD: For a beginner or moderate wheeler, what type of adjustable shocks will give them the best bang for their buck?
Wayne: Well, there are several different types of adjustable shocks; a good starting point is the FOX DSC adjustable shocks. Keep in mind that DSC adjuster only affects the oil at the bottom of the shaft. Depending of the vehicle being used, you still need a shock that is in the range of operation of the particular vehicle and driving style, and then from there, you can soften or firm up the dampening for your specific needs.
So, while effective, it is not able to go to the extremes of the ability of the shock. But they do allow you to soften things up for a smoother more comfortable ride on the street, or firm things up so you can go a little faster off-road. Or whatever the driver finds they prefer in their own driving style.
4WD: Now, many adjustable shocks like your DSC system offer high and low speed shock tuning. What does this refer to?
Wayne: High-speed compressions or rebounds are just that, events the result in the shocks shaft making fast and abrupt movements such as hitting a pothole or landing from a jump at speed. Low-speed events typically happen when weight transfers onto the suspension. A good shock will allow you to adjust both high and low-speed movements, allowing you to fine tune for your specific needs.
4WD: Is there an ideal setup, where do you start as a baseline when tuning adjustable shocks?
Wayne: In a perfect world for me, I would want an everyday driving tune to be fully open on the high-speed compression, and the reason for that is when you start closing them and they restrict flow of oil, this creates an artificial harshness on the small bumps. Now when I say small bumps, that can still be a high shaft speed event and that would be harsh in that small movement, which translates into just a harsh rigid feel through the chassis. So for me in everyday driving I like to tune the truck so that it gives the best ride fully open.
Now when when I go for a four-wheeling trip, I now have the ability to get under the truck and turn it down to a level of 5 for slower off-roading situations. And then if I decide I want to race someone to the top of a mountain for a case of cold beer, then I can tighten it up the whole way.
Now its not going to go from Cadillac to Trophy Truck, but it is going to give the everyday wheeler a little more adjustability with a simple turn of the knob.
4WD: For those who are getting into adjustable shocks for the first time, what tips can you give them for setting up a 4WD?
Wayne: If you are getting into adjustable shocks for the first time, make sure you get out and play with them. Don’t be scared to start turning the knobs and finding out how that affects the truck. It always helps to keep notes for different settings and environments to get the most out of your shocks.
For those who do have a little more experience, there is a common misconception that when the back bucks, everybody adds rebound to keep the back from bucking. Typically what I find in my experience, is that typically the back bucking means the front has a bump and transferred a great deal of energy to the back, the back hits hard and compresses the tire. Now the tire acts like a giant basketball, jumping the back of the truck up. So, how we fix that is we dissipate more energy on the compression stroke. I see a truck hitting a bump and bucking, and I see a tire stuck up in the wheel well, that means the rebound isn’t fast enough, so if the buck is actually being caused by a rebound event, you’ll see that the truck bottoms out then it shoots the truck up like a pogo stick, 99% of the time the tire stays in the wheel well as the truck lifts off the ground, then slowly begins to fall so you know that’s not caused by rebound if that’s the case.