Improve How Your Suspension Works
Modifying your vehicle’s suspension is an integral part of the off-road hobby. Whether you just need a slight lift to manage the local hunting-camp backroads, or a long-travel setup for legging through boulders, tuning your rig’s suspension to fit your needs is easier than ever. From control-arm lengths and shock valving to bumpstops and sway bar disconnects, there is an array of components and factors to consider when tuning your vehicle. Collectively, the magazine staff has a decade’s worth of suspension building and testing experience. Like many of you, we have learned the easy and hard way as to what works and what doesn’t. To get a better idea of what each of us has learned over the years, the crew weighed in on some of their favorite and not-so-favorite suspension setups.
I like to keep my 4x4s low. Unless you’re building a 4x4 to bash over rough terrain at a significant speed, you don’t need a ton of uptravel on the suspension of your 4x4. This is especially true if you only crawl at slow speeds. You might even consider having your suspension nearly rest on the bumpstops. The lowered center of gravity will make the rig more stable on sidehills and climb ledges better.
I prefer stiffer leaf springs if I’m running a spring-over configuration. Don’t go nuts with overly flexible leaf-spring packs. Leaf springs that are too soft and offer too much travel cause numerous other issues such as handling quirks, steering linkage problems, driveshaft binding/failure, axlewrap, and more. Firmer springs are better at controlling axle movement and driveline torque. It’s true that firm springs may allow a tire to lift in some situations, but that’s why we have lockers and other traction adding differentials. Letting a tire dip down into a large hole can often create more problems for both leaf-spring and link-type suspensions than if the tire is simply carried airborne over the hole.
There is more to your suspension than springs and shocks. The tires and wheels are an integral part of a 4x4’s suspension system. I always run the smallest diameter wheels I can reasonably fit on my 4x4s. Big wheels are heavy and are a detriment to suspension, acceleration and braking performance. More tire sidewall will cause the 4x4 to handle less crisp, however the benefits of a taller sidewall include a smoother ride and less shock-load stress on wheel bearings, steering parts, and other suspension and axle components.
I compensate for firmer springs on my 4x4s by significantly lowering the air pressure in my tires off-road. With beadlocks, most vehicles can get by with about 8-15 psi on a radial tire and 2-10 psi on a bias-ply tire with a sturdy sidewall carcass. The deflated tires envelop obstacles and not only offer a smoother ride over rough terrain; they provide improved traction and flotation in mud and sand.
Most 4x4s don’t need any more than about 10 inches of total wheeltravel (measured at the bumpstops), unless you’re speeding across the desert regularly, jumping your 4x4, or entering the local RTI ramp-champ competition. Keeping your suspension travel limited will improve the overall versatility, performance, handling, and reliability of your 4x4. The jaw-dropping flex of the RTI ramp champ at the fairgrounds may make for a cool photo, but it’s never the best trail truck. Use proper antisway bars, limiting straps, and bumpstops to keep coil springs from rattling loose and falling out of their buckets, shocks from topping and bottoming out, driveshafts from binding and separating, and tires from rubbing and being cut on the inner fenders.