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?
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
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
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.
H&R Special Springs
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.
When you're looking for a set of lowering springs, you are bombarded with many choices, each company claiming to be better than the next. The most important question besides "How low you want to go?" is "Were the springs designed for a U.S.-spec vehicle or were they imported and just happened to fit?" The latter scenario is more common than you think and can often lead to uneven ride height, bouncy ride, and overall poor performance. The differences between the U.S.-spec model and its European cousin include weight, spring rates, and shock valving. Neuspeed Sport Springs for the new 2010 VW GTI are designed and tested at the Camarillo, Calif., facility specifically for and on the U.S.-spec GTI. In addition to the 1-inch drop, the springs help reduce body roll during cornering and dive under heavy braking.
Flex is not limited to the vehicle's upper strut towers; it can occur at any weak point where energy is transferred through the chassis. Car manufacturers do what they can to eliminate chassis flex and some do a better job than others. In the end it really comes down to two things: cost and comfort. The more flex you eliminate the more it costs and the ride quality diminishes. Manufacturers' attempts to reduce flex are more obvious when you compare a sport and non-sport version of the same vehicle-you will often see parts of the chassis that have been reinforced and a possible tie-bar or two installed on the sportier model. And even though the '09 VW GTI is considered a sporty model, Volkswagen doesn't treat its underpinnings any differently than a standard 2.5L Rabbit. That's why GTSPEC has developed a complete line of under-vehicle chassis braces. Each GTSPEC brace is designed to increase rigidity by targeting a specific point of chassis flex and reduce its effect, resulting in increased steering response and sharper handling.
Front Lower Tie Brace Price: $160.00
Mid Chassis Brace Price: $114.00
Rear Lower Tie U Brace Price: $114.00
Rear Lateral Tie Brace Price: $160.00
An often-overlooked problem is incorrect suspension geometry-not only does it impact your drive, but also your wallet. I am often amazed when people spend $800 or more on a set of ultra sticky tires and then don't check the vehicle's alignment. Instead of letting you take full advantage of the new tires, they'll be unevenly worn away and in six months you'll be in need of another set. The difference between an increase in handling and an increase in wear can be as little as a half a degree of camber. On most modern VWs, the front suspension is set from the factory and is nonadjustable. So if the front alignment shows the camber to be off, the whole stock front suspension will need to be changed. H2Sport came up with a quick fix solution: sport camber mounts with 0, 0.5, 1.5, 2.0 degrees of camber adjustment, enabling you to either fix or enhance your vehicle's handling characteristics by ensuring optimal tire contact patch. The H2Sport mounts are made from billet aluminum, with stainless steel hardware, PTFE line bearings, and are a direct replacement for the factory upper strut mount.
Upgrading antiroll bars is an effective way of enhancing handling characteristics of any vehicle, even if the rest of the car is stock. Since the antiroll bar is linked to both sides of the suspension, it evens out compression that occurs during cornering when the body of the vehicle rolls under the force of the turn. Increasing the bars' rigidity translates into less body roll, which gives increased handling and stability by balancing the chassis and reducing recovery time after a turn and providing even tire contact. Most daily drivers will benefit greatly by simply swapping out the rear bar. If you're looking to go beyond the daily driver setup for something that will allow you to tear apart a canyon, look into a full antiroll bar set like the Hotchkis Sport Sway Bar package for the E36 BMW 3 Series. While components and details vary based on the vehicle, the concept is the same. The kit for the E36 features 33.4mm front and 25.4mm rear adjustable antiroll bars, bolt-in rear subframe reinforcement brackets, adjustable end links, and greasable polyurethane bushings.