The idea is casually tossed about in tuner circles like it's as easy as adding a new air freshener. In truth, "suspension upgrades" is a broader term encapsulating many components: shocks, springs, tie bars, sway bars, coilovers, and so on. This guide is intended to help you ply those murky waters.
Before doing anything to your car's underpinnings it's a good idea to formulate a goal. What is the purpose of the modification? Is it simply to firm up the ride and lower the chassis or make the ultimate canyon carver? Is the car a daily driver or a weekend weapon?
Suspension mods are best accomplished in stages. Try not to add everything at once or dial settings to their highest value. You'd be surprised how little modification some cars need. Ultimately, it's a question of compromise. What are you willing to sacrifice for handling?
Wheel spacers
With wheel spacers, the name pretty much explains the function, but it does not encapsulate their multiple purposes. Macht Schnell Competition Spacer Kits for BMW are available in various sizes, from 3 to 18mm, and provide several useful functions. Spacers can be used to increase wheel and suspension clearance, allowing your favorite wheels or winter tires to clear your big brake kit. In addition, they can also be used to eliminate the "sunken wheel" effect, bringing an aesthetic balance, and a more aggressive stance. Macht Schnell Competition Spacers' primary purpose is to increase the vehicle track width, and depending on the size being used they can increase a BMW's overall footprint from 6 to 36mm, resulting in increased lateral stability.
Prices: Vary by size
Shock Absorbers
A good set of shocks (struts, dampers, or whatever you want to call them) is critical to keeping a vehicle safe and under control in all driving situations. Choosing the right shocks can be difficult and is a task that should never be taken lightly. The wrong choice can make your driving experience a miserable one, so it is always best to consult with more than one source, especially if you plan on lowering the vehicle. When I decided to modify my A3's suspension, I planned on doing a 1.8-inch drop with Neuspeed race springs and combine them with Bilstein Sport dampers. The result was exactly what I was looking for: a firm ride that didn't snap necks over road imperfections and held tight in the corners. Quality dampers aren't cheap but are an investment in both safety and overall driving pleasure. If you're planning to lower your vehicle, upgraded dampers are a must. If it's is a matter of money, just remember that in the long run it is always cheaper to do it right the first time.
Price: $626.40 (market estimate)
Applications: Most vehicles
Coilovers
If you think coilovers are just for people who want the ability to dial in the perfect ride height or to raise the car back to stock height when winter comes, you would be partially right. H&R's Street Performance coilover kit for the BMW 135i offers drivers so much more than height adjustment-it's a complete solution that eliminates the concern of whether this shock works well with that spring. Each component in the Street Performance kit has been custom tuned to the 135i chassis. Since every damper has been custom valved to match spring rates, they will work perfectly even if you decide to opt for the full 2-inch drop. H&R coilover systems are constructed to meet or exceed ISO 9001 quality assurance standards.
Strut Tower Braces
When you round a corner, the suspension compresses and energy transfers in multiple directions, up from the wheel to the strut and spring and eventually across the entire body. Over time, as the energy travels through each component, the force slowly starts to diminish. The problem with the MINI is that it has nothing to restrain or continue the energy transfer past the strut towers, causing all of the remaining force to be focused at that point. During aggressive cornering, increased forces heighten the chance of strut tower deflection, which can adversely affect suspension geometry or alignment. The NM Engineering front upper tie-bar is designed to reinforce, transfer energy, and reduce the multi-direction flex in the strut towers and help to reduce side-to-side movement, eliminating strut tower deformation (mushrooming), and eliminating unwanted changes in suspension geometry. This bolt-on mod helps improve handling and increase steering response. Plus, it looks great installed inside the engine bay.
Price: $299.95