In the aftermarket world of cars, we yearn to chase parts that offer us the highest return on investment through form and/or function. Oftentimes, we spend hours upon hours scouring forums and picking mutual enthusiasts' brains for advice, but a concrete answer is almost impossible to come by. What one may think is the most viable option for coil-overs on his BMW M2, for example, may be the least favored choice by another. Suspension preferences are among the most subjective options on any given car, and in an environment where performance and sprung harmony is paramount, there is little to no room for error in choice. Thousands of dollars in parts and labor, hours of time and labor spent in research or installation mean that a good setup should be a one and done scenario, where one would hope they could spend the rest of their time with the car on the track and not under the knife.
While it is the common consensus and the seemingly safe option to go the route of name brands such as KW and H&R for higher end suspension, or Tein and BC Racing for lower end options, either option may not be the best bang for the buck, precisely when options that offer full adjust-ability, control, and maximization of performance potential exist. While these brands do offer custom coil-over options, they tend to do a moderate job of both spring and damper manufacturing. Yes, niche manufacturers such as MCS dampers and Swift springs that specialize in one or the other will cost considerably more paired together, but as the slow and fast-twitch muscles, nerves, and joints of your car, the optimization of suspension components can make your $40,000 M3 punch way above its weight class, and make you look like a superstar on track while doing it.
The reason for this goes back to the importance of weight transfer, as even in street driving, your car will always want to unsettle itself. Turning, accelerating, and braking forces cause a vehicle to lose grip in certain areas, while increasing grip in others. This could lead to an unwanted instability, which could not only hamper performance, but put the safety of the driver at risk. While the effects of weight transfer vary depending on drive-train configuration, the consequences will always bear weight (literally) on the suspension components of your car. Normally people associate coilovers with being low and having a stiff ride and this is the sacrifice that needs to be made to achieve better handling. But that's not the case, gone are the days where comfort is sacrificed when having a stiff suspension setup, as the progression in damper and spring technology allows for excellent ride quality while offering the best of handling. With certain suspension setups, no compromise needs to be taken anywhere, and this is where the beauty of the adjust-ability of a high end motorsports grade damper takes play.
For our customers, we recommend Motion Control Suspension (MCS) as their damping, and Swift for their springs. This coil-over match up results in the hands-on feel of two companies based in the USA working tirelessly to specialize in a trade of their own, bringing you one of the most harmonic mechanical experiences you would have only believed to exist in million dollar race cars. What these two companies have that name brands don't is their own respective competitive edge in both design and performance. Motorsport dampers are expected to offer the highest quality in build construction, from the adjustment knob clicks to the quick release nitrogen reservoirs.
Features like a monotube construction should come standard in a top-of-the-line damper, and offer better oil-capacity, heat-dissipation, fluid displacement, and more accurate damper response thanks to the large main piston. Furthermore, the divider piston separates oil and gas, which is crucial to eliminating the possibility of liquid to gas formation under low pressure scenarios. Blow-off valves, yes, the same concept seen in turbo applications are also a necessary part of a motorsport damper. These valves prove effective by regulating damper compression at high speed by bypassing one's suspension regardless of whether it is set to the stiffest setting, allowing for the suspension to gracefully take high speed hits without unsettling the car. Lastly, the orifices of the damper give you full control of damping adjustment through a wide range operated through individual clicks, allowing for consistent damper pressure and avoiding costly damper re-valves.
Now that we've covered what makes a damper worthy of motorsport duties, we can move on to the second most significant part of a coil-over assembly; the spring. Springs are much simpler than a damper assembly, but require a lot more initial thought as the rate in which a certain amount of force needed to compress the spring is set, and non-adjustable. While many name brand companies advertise certain spring rates for springs sold, we have found that a difference in rates between each spring is evident regardless of front or rear springs advertised as a set rate. This leads to inconsistency in not only spring performance, but on-track performance. Data can be skewed, especially when race cars undergo the process of corner-balancing, where compounded variables must have set parameters to achieve a desired outcome.
We have found the best springs to be from Swift, and that their in-house metallurgy allows for the spring to have the consistency of rates as advertised. Having consistent spring rates throughout the car drastically increases chances of data improvement and better data gathering, as there are less outlying factors to work around such as inconsistent spring performance. Tire wear is also consistent, allowing you to focus on being a better more confident driver. A good motorsport spring should also aim to save weight, as decreasing unsprung mass should be carried out wherever possible. Swift Springs not only function to the highest standard, but contain form while doing so. Their in-house proprietary material allows for the color of the elements used, to be the color of the spring. This means that chipping or damaging the "color" is almost impossible, rather the only deflection of the color would be due to fading evenly over time.
In conclusion, choosing the best suspension option may not necessarily mean choosing name brands, as the testament quality versus quantity holds true in this case. While companies like MCS and Swift Springs are not as well-known as KW, H&R, and the likes, both paired together will meet the highest standard of a motorsport oriented coil-over suspension setup, where others fall short. And with the dynamic needs and nature of vehicle suspension, every improvement counts. Yes, top of the line dampers and springs can be costly, but you truly get what you pay for.