SCORE Journal - The Official Publication of SCORE Off-Road Racing
Issue link: https://read.uberflip.com/i/1541562
SDG SUSPENSION Where Off-Road Racing Shocks Go To Get Reinvigorated By Dan Sanchez and Larry Saavedra Driving through deep ruts, rocks, pavement, and whoops at high speeds will destroy most shocks, but racing shocks are built to withstand severe off-road abuse and live to do it again...sort of. After a tough SCORE Baja race, many top racing teams bring their vehicles to SDG Suspension in El Cajon, California, where racing suspension gurus Todd Tenbroek and racer/navigator Justin Davis rebuild the racing shocks from the ground up. The two started SDG Suspension in their garage in 2017 after Tenbroek quit working at Fox, moved to Australia, then moved back to California, and became Duncan’s roommate for a while. Davis was an experienced off-road racer, but realized how expensive it was, so he decided to focus on navigating and suspension tuning. Knowing that together they could create a unique suspension tuning business, the two started the company with two shock benches, and their success began. Tenbroek and Davis have redefined off-road suspension tuning using the vehicle’s ride height as the baseline for the tune. According to Davis, the traditional way of weighing the vehicle to determine the optimum suspension settings doesn’t work in off-road racing. “First, we determine the size of shocks that are needed depending on where the vehicle is being raced, the size of the tires, and other factors, “ he said. “When it comes to measuring a car, we’re different in the fact that we don’t weigh them. The old method of scaling and figuring out corner weight is just a guess. It’s a circle track racing thing where all the chassis are the same and the geometry of the vehicles is the same. Off-road race vehicles are so different, so you can’t do that. We take a bunch of spring and shaft measurements to find out what the springs are doing, and then put that information into a computer program and figure out the springs that the vehicle needs. Once I know the springs it needs, then I know what valving it needs. Then it’s all math. It’s simple but complicated at the same time.” Tenbroek and Davis call their system their “secret sauce,” and it has proven successful on the top SCORE Trophy Trucks and Class 1 Buggies that win races. Teams such as McMillin, Menzies, Wilson, Ampudia, Herbst, Price, and more have won or been on the podium more times with SDG Suspension tuning on their vehicles. “We cycle the suspension on the computer with every spring kit imaginable. To set it up, we need the vehicle heavy, at its race weight, set ride height, full fuel, etc., to see what springs we need to set that ride height and spring curves. Then I know what valving the springs need to be.” The SDG team then takes apart the springs, fully reconditions them with intricate precision, and reassembles them, placing them back onto the vehicle. “If the vehicle then sits at the same ride height, then we know we have the right set-up,” says Davis. “When we go to the desert to test, the setup should be at 90 percent. Then all we’re doing is changing a couple of settings on the spring, dampening, and rebound.” Part of the tuning process involves Duncan riding with the driver to add the last 10 percent of fine-tuning to get the vehicle race-ready. Duncan can relate to driver input because he’s been a race driver in the past, and is currently one of the top navigators in the sport, riding with Luke McMillin. He’s also raced with veterans like Toby Price and others, so he’s careful not to disclose what he knows about each of his customers’ set-ups. “I give everyone the same suspension tuning,” says Davis. “It’s all based on driver preference and what I feel with them. The valving and spring rates are all different because it’s what they personally prefer, and it’s what makes them feel more confident when they are driving. It’s all custom-tailored to them.” “During pre-running, some drivers will tell me that their vehicle acted a certain way on one section of the course, or that it felt different. So I can always relate to what they are saying because I went through that section too. Then I can offer advice for making changes depending on the situation.” Methodical Rebuilding Processes When teams bring in their vehicles to SDG for the full shock treatment, it begins with a complete exterior power wash. Upon disassembly from the vehicle, every spring, tube, and valve setting gets documented and inspected. Then the shocks get taken apart and go through the sonic cleaner and solvent tanks. Larger parts like the aluminum bodies are honed, and the shafts are polished and inspected. The top caps of each shock are removed, and the O-rings are replaced along with the main seal. All of the large and small components are organized, and the smaller assemblies, such as pistons and valves, are put back together before the larger components are assembled. The larger shock bodies are fully lubed and prepared for when the shafts and valves are inserted. Those components are taken to the valving bench, where all the components get inspected and measured, and where all that info is input into a computer, where everything is documented. Then the shocks are assembled with oil and placed back on the vehicle. “A team can tell us, for example, that in 2022, during the SCORE San Felipe 250, we really liked how the car worked. We have all of the information documented to replicate those settings.” Along with racing applications, SDG Suspension also offers custom tuning on both racing and consumer UTVs, buggies, and more. “We treat all of our customers the same, whether you’re a recreational off-road person or an off-road racer. We tune kits for people heading to Glamis for the weekend or for a full race.” As you would imagine, the company is insanely busy, but as it continues to grow with an increasing customer base, Tenbroek and Davis are dedicated to providing what they consider the best suspension prep and tuning in the business. SJ