Your car’s suspension is one of those areas that’s often overlooked by car modders. It’s not the sexiest upgrade in the world: a new sway bar or set of shocks is never going to sound as cool as a new engine or transmission, but it’s extremely important. Your car’s suspension affects just about every aspect of your car’s performance. From the more obvious aspects, such as how it rides, to the downforce that keeps your car gripping the road, to weight distribution, the right upgrade can improve your whole car. The various systems can seem pretty baffling, though. A car’s suspension isn’t made up of a single part that you can just rip out and replace, there are several key components. In this guide, I’m going to go through each component, discussing what they do, how they do it, and how much an upgrade should cost, so that you can be better informed for your next project.

Sway Bars

Sway bars are a component that’s not standard on a lot of older cars, but they can dramatically improve your car’s stability. The bars connect the wheels on each axle, meaning that the amount of roll that’s transmitted from one side to the other in a turn is limited. The bar twists with the stress from each side, transmitting torsion from one side to the other, keeping the car’s weight on the inside of the tires, improving traction, and helping to keep your car controlled. Like many things in life however, sway bar thickness offers diminishing returns. As the bars get thicker and stiffer, and you get faster, the amount of independence offered to each side will begin to lessen. What this means is that with too thick a bar, the inside of the tire can lift while cornering, meaning it isn’t only roll in the body you’ll have to worry about.

If you have a stock bar already, begin by upgrading its thickness. If you just want to slightly improve your car’s cornering ability and lessen roll, you won’t need to upgrade it by much. Don’t think that you’re going to need to jump drastically in terms of thickness. An increase of just 1mm in diameter can improve rigidity by 20 percent over an OEM bar, while a hollow, rigid aftermarket bar can improve rigidity by up to 40%, at the cost of 1.8mm of thickness. When the bar’s been fitted, its stiffness can also be adjusted based on the simple principle of leverage. Many sway bars have several holes in each end, meaning you can cutomize the stiffness as necessary. If you attach it with the hole closest to the actual bar, the ride will become stiffer, while using the link further from the lever will allow more roll to be transmitted. When it comes to cost, you should expect to spend around $250 per sway bar for a high quality component.

Springs And Shocks

Now we move on to probably the most obvious suspension parts around. These two parts have the greatest effect on how the car feels to ride in, and how it handles. Shorter springs and more heavy duty shocks make the ride stiffer and tend to make the driver feel every single bump, but allow for improved handling. This is due to the car being more lowslung, with the stiffer suspension maintaining consistently low ground clearance, even when cornering. This in turn allows for lower air resistance and a low center of gravity, sticking the car to the road.

However, if you’re restomodding a classic cruiser, like a Cadillac or an Impala, this may not be what you’re after. If you’re in one of these cars, the chances are that speed is an added bonus, rather than your primary objective. What you want is a soft ride. For this, you’ll want to get softer and longer springs, and less stiff shocks, but you could also go another route. Enter the air ride. Air ride suspension is becoming increasingly popular among restomodders for its sublime ride quality. Instead of using springs, air ride systems use “air springs”, rubber bags which contain highly-pressurized air. The advantages of this are numerous, with the most obvious being a smooth, controlled, and comfortable ride. However, the downside of such a system is that it requires having a compressor, sensors and other electronics fitted too. These systems also allow the ride to be altered on the fly as necessary, giving you low ground clearance when you want some speed, and lifting you up when you’re just cruising on the freeway.

Which side of this dichotomy you go down really depends on your car and your own personal preferences. Are you driving something like a Barracuda, or a Camaro? Then you’re probably going to want the most speed you can get, so take a leaf from the books of high-performance European cars, and grab yourself stiff, short springs. The ride may suffer, but it will give you vastly improved cornering abilities and a firmer, more planted grip on the road. If you’re in a cruiser or really don’t care about speed as much as being comfortable, then either go for longer springs and more compliant shocks or, if your budget can stretch to it, consider air ride suspension. Your butt will thank you.

When it comes to shocks, you can also consider grabbing adjustable shocks, which, as the name suggests, can be stiff or lax. Take coilovers, a type of hybrid spring and shock, where the spring is wrapped around the shock, allowing for adjustment of ride height and stiffness as necessary. I’d typically recommend against the “Jack of all trades” mentality, and choose one or the other, but it’s up to you. For an air ride system, you can expect to pay around $3000, while a set of four coilovers should cost around $1000 or less.

Strut Braces

Strut braces do exactly what it says on the tin — attach to the top and bottom of the strut towers. Like the sway bars we talked about earlier, this serves to limit chassis flex, this time by preventing the strut towers from warping. This isn’t a problem on a lot of cars, but once you start to increase a car’s grip, the increased levels of traction could cause the struts to deform. Luckily, strut braces are fairly simple to install and pretty cheap.

These should serve as your last upgrade when it comes to the suspension. They effectively work to tie together all the rest of your good work, keeping everything aligned and working as it should. They’re also cheaper to buy and install then a roll cage, which is your other primary option for reducing chassis flex. For a strut brace, expect to pay anywhere from $100 to $400.