Improving A Suspension Template: How Koni Tunes For Performance

On a fundamental level, a well set up performance car is one that can make effective use of its tires. Although horsepower can overcome some handling deficiencies when it comes to fast lap times and overall track prowess, keeping the rubber in contact with the road is crucial to not only cornering and braking, but the ability to get on the power effectively on corner exit as well. All of that requires a properly dialed in suspension system.

Not only are OE dampers selected and built to a meet a specific price point, their tuning is often compromised in a performance context, either to yield agreeable ride compliance for a wide range of customers, or to deliver a “sporty” character that meets the expectations of casual enthusiasts – the latter of which can come at the cost of harshness and overall stability. Koni looks at these potential issues when designing its dampers in order to deliver better handling that actually improves ride quality versus the OEM dampers in some cases.

While tuning a track car for a given race course is a relatively straightforward proposition, the story gets trickier with daily-driven high performance road cars, as the suspension outfitted to those machines is asked to perform well on a much wider range of surfaces while maintaining a livable ride quality. OEMs have made significant strides in that regard in recent years, but the design limitations inherent to mass-produced vehicles still leave a lot on the table for enthusiasts.

That’s where Koni comes in. For decades the shock absorber manufacturer has been developing dampers for racing as well as street-driven vehicles with a focus on delivering improved handling performance through meticulous research and development for each specific platform they design products for.

We recently sat down with Lee Grimes, Automotive Product Manager for Koni America, to get the latest on how the company develops its production car-based products and discuss some of the differences between a Koni damper and something you might find outfitted to a performance machine that’s just rolled out of the factory.

Developing For The Auto Industry’s Latest and Greatest

You might assume that Koni’s damper design formula for modern road cars is to simply tune the dampers for a firmer ride and a sportier on-road feel, but the strategy goes much deeper than that. With dozens of new or heavily redesigned vehicles released each year, aftermarket companies like Koni must also decide which vehicles to focus its development efforts on.

Koni’s FSD (Frequency Selective Damping) damper automatically adjusts to road conditions as well as driving style via a special valve which controls a parallel oil flow next to the one going through the piston. This parallel oil flow is closed by the FSD feature, giving a rise in damping force almost linear to the time that the piston is moving in one direction.

“We target each new application from a mix of consumer and dealer input and our own general market and media awareness of new vehicles coming out that might be of interest to car enthusiasts,” Grimes says. “For example, when the advanced word got out to the public that Subaru and Toyota were going to come out with a new rear-wheel-drive sport coupe that became the BRZ and FR-S/GT86, my European counterpart and I were all over it and grasping for every bit of info, suspension illustration, etc. prior to the car’s release because we knew this was going to be a Koni customer car. Every new Mustang, MX-5/Miata, and so on are pretty much ‘must do’ developments for us, too.”

Once they’ve zeroed on a vehicle they’re doing design dampers for, the first step in development is establishing a packaging template based on the OEM hardware. “When the actual cars first hit the market, we do our best to get sample sets of the factory dampers so we can begin the physical design work and start sourcing the external components like spring perches, mounting brackets, brake line or sensor tabs, etc,” Grimes explains. “As the latest generation ND chassis Mazda MX-5/Miatas were first unloading off ships onto the U.S. shores in 2015, we tracked down and bought literally the very first few front and rear factory shocks that entered the U.S. and Canada not attached to cars through Mazda’s parts support network. We kept some in the US and we sent some to our factory in the Netherlands to build prototypes and start sourcing components.”

After Koni has worked out the dimensional requirements, they can begin the process of damper tuning for a specific chassis. “Once we have prototype shocks ready for testing, we locate and drive the car to decide what ride and handling characteristics need to be improved and which aspects are already good and need to be kept,” Grimes tells us.

Designed for performance cars and light trucks, Koni's STR.T line of shocks and struts are designed to provide handling improvements over the stock components without breaking the bank to do so.

Interestingly, Koni’s “default” setting for its dampers isn’t somewhere in the middle of its adjustment range, as we’ve found with other adjustable dampers on the market. “We develop a damper’s valving at the full soft setting on adjustable shocks to give us the target ride and handling baseline that we feel best represents our team’s goals and our customer’s demands for that vehicle in stock form, or with mild performance upgrades. From there, the broad rebound adjustment range on our adjustable shocks is available for end user tuning to their own car modifications and driving and ride expectations. For our non-adjustable shock offerings like STR.T and FSD, we will use that baseline and then tweak it further depending upon the technology and target outcome.”

The Role of Shock Dyno Testing

Grimes says that while shock dyno testing can provide a visual representation of how a component’s rebound and compression characteristics behave under load, it’s only one piece of the puzzle. “There’s a general shape that you would like to see, but there isn’t an ‘ideal’ graph for each application or car.”

While real-world testing is where much of the fine-tuning is done before a damper valving is finalized for a new product, a lot of the initial work is performed in the shop using a shock dynamometer. The dyno operates a shock absorber or damper through a range of motions, piston speeds, input frequencies, and so on, and then reports back the damping forces and characteristics from the test.

“There are many types of tests and dyno designs to perform them, including ‘force vs. displacement’ operating at one piston speed, ‘force vs. velocity’ plotting multiple piston speeds, different frequencies or durations at the same or multiple piston speeds, and so on,” Grimes says. “All can be helpful to the damper engineers to help refine the damper characteristic that they are looking for.”

The old adage that “numbers don’t lie” can be a pitfall for enthusiasts though, as it’s all too easy to take dyno readings as gospel, say Grimes, and the dyno results don’t necessarily tell the whole story about the behavior of a damper out on the road when working in conjunction with the rest of the suspension. “One key point that often gets lost is to remember that a shock dyno is simply a testing machine that is only one of several ways to collect shock data –  it is definitely not the final answer for damping needs,” he says.

“The dyno isolates and quantifies the damper valving’s output, but on a vehicle the damper is only one of several suspension and other parts that must operate well together on a real-world road for a driver and passengers. Enthusiasts often want to put too much emphasis on the dyno portion alone of the damping equation, when in reality it is only one tool to measure one aspect of a large and complicated assembly of parts and people. With lots of experience, our engineering team knows how tuning the various components inside the damper can make the car respond to reach the targeted goals and performance when the car is being driven.”

One key point that often gets lost is to remember that a shock dyno is simply a testing machine that is only one of several ways to collect shock data –  it is definitely not the final answer for damping needs. – Lee Grimes, Koni

Rather than a picture of a shock absorber’s behavior when put into use in a vehicle, the dyno provides a precise technical measure of a specific design, which helps engineers get a clear picture of how a particular valving works during operation so they can make clear comparisons between different prototypes when they test those designs out in the real world.

“We work with different parts of the shock valving system like oil flow through or bypassing the piston components, different orifice sizes, different strength coil or wave springs, different deflecting metal discs, and much more on both the rebound (extending) and compression stroke of the damper at a range of piston speeds and input frequencies to get different responses that best meet the damping needs of the car,” Grimes explains. “The shock dyno allows the engineers to graphically see how that particular valving is responding to different piston speeds and frequencies, and they try various options on the car to get the best characteristics in real world usage.”

Going Beyond OEM Quality

While OEM suspension design and capability has come a long way in the past few years, it’s important to remember that automobile manufacturing is a business proposition, and the goal is to maximize profit by minimizing the expense required to yield the desired results. Considered on a scale as large as a mass-produced car, which may see hundreds of thousands of examples produced, the inherent compromises required to keep costs down become obvious.

Koni has recently expanded its efforts to offer a wider range of products for late model vehicles, as evidenced by the products they showcased at the 2017 SEMA Show.

“Factory shocks are almost always significantly compromised, in terms of internal quality and technology, based on the price that the car manufacturer is willing to pay for them in very large volumes,” Grimes points out. “This means that there can quickly be factory shock compromises in ride or handling that we can later mildly or sometimes greatly refine with a higher technology and more expensive shock than the vehicle manufacturer would have accepted.”

Perhaps the most obvious benefit of moving to an aftermarket damper is to address a factory setup that’s tuned to keep the widest range of potential buyers happy with the ride quality, and that often runs against the needs of enthusiasts. “Sometimes factory shocks might make the car feel too floaty and disconnected from the road, so we can refine the damper valving to give the car a level of responsiveness and awareness that makes the car so much better while not sacrificing ride quality on imperfect surfaces,” Grimes says. “Control and some level of firmness is good, but harshness is not.”

While shop testing can help engineers zero in on the valving requirements for a particular application, Grimes says that much of the fine tuning is discovered through real world testing on the road and at the track.

On the opposite side of the spectrum, a curious side effect of this compromise can be a factory ride quality that’s actually harsher than it needs to be so that it delivers the sensation of an aggressively sport-tuned suspension. But Grimes points that this approach can actually reduce the overall road holding capability of the vehicle. “All too often, in an effort to make a car feel sporty, an OE shock can become needlessly harsh on bumps and road inputs, often not only making it less comfortable in the car but also sacrificing stability.”

Out on the road, the autocross course, and the track, that often translates to less grip when getting on the throttle out of a corner, reduced confidence over uneven pavement, and a greater likelihood for a loss of traction when encountering a mid-corner bump. “What we can do is trim off some of that harshness while adding firmness and control. By keeping the tire better planted and less likely to be upset by an unevenness in the road, you can actually put the power down earlier in a corner rather than having to wait for the car to settle down.” And that, of course, translates to improved stability and faster lap times.

If you’re looking for a way to improve the suspension setup on your ride, a simple damper swap might be just the thing you need to really dial everything in. The folks at Koni can help you determine exactly what you need in order to get your suspension to behave the way you want it to, both on the road and out at the track, so give ‘em a buzz and find out what you’ve been missing.

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About the author

Bradley Iger

Lover of noisy cars, noisy music, and noisy bulldogs. Brad can often be found flogging something expensive along the twisting tarmac of the Angeles Forest.
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