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More than Meets the Eye: Santa Fe’s Performance Evolution

2020-08-13

The new Santa Fe’s evolution is more than just a typical facelift: there have been significant, more fundamental changes under the hood that have led to drastic performance increases.

The new Santa Fe is finally here, with a sharp new look that stands in stark contrast to that of the previous models. But calling it a facelift undersells the degree of change the model has undergone. The engine has been changed. The powertrain is now more eco-friendly and powerful. It even comes with a completely new platform.

That’s not all, of course. There have been several subtle changes that have contributed to a real performance increase. The suspension and the brake system, both parts with direct influence on vehicle performance, were amended; NVH (Noise, Vibration & Harshness) countermeasures, which influence passenger comfort, were also improved upon. Safety features were improved as well, particularly in the collision safety aspect. A new Terrain Mode is available for those with off-road aspirations. The changes to the new Santa Fe are more than meets the eye, leading us to conclude that the model has become a quintessential family SUV.

The New Suspension, Offering Stability and Comfort

Ultimately, Santa Fe’s identity is a family SUV—so ride comfort has meant a lot to the model throughout its four generations. The new Santa Fe, though, shines particularly in this regard, thanks to the 3rd-generation platform and a new suspension. Despite being a facelift version in a technical sense, the Santa Fe underwent these changes to stay true to the family SUV identity and bolster the consumer trust in this steady-seller.

The 3rd-generation platform on the Santa Fe has already been introduced via Hyundai Motor Group’s other models. The platform has several advantages of note: its lower center-of-gravity improves on stability, and its lightweight-yet-stiff design makes for agile but anchored movement of the car.

New Santa Fe’s front suspension changed the angle of the strut bearing to improve directional stability.

The most visible structural change on the new suspension is the form of the strut bearing on the front suspension. The previous 4th-gen Santa Fe had its strut bearing in a perpendicular placement; as a result, the kingpin axis (a hypothetical axis determined by the suspension bearing and the lower-arm geometry) and the bearing’s rotation axis were separated by 6.9 degrees. This large relative angle is not ideal, as the increased friction on the suspension during a change of direction reduces directional stability. To address this issue, the new Santa Fe’s front suspension strut bearing comes with a 7-degree angle adjustment that reduces the above relative angle to 0.1 degrees. The resulting decrease in friction on the suspension, consequently, helps improve the vehicle’s directional stability.

The diameter of the rod inside the rear suspension damper was increased to improve ride comfort.

There was a change to the rear suspension well: the rod inside the rear suspension damper received an enlargement, from 13mm-diameter to 15mm. This change, while seemingly minor, is the reason why the new Santa Fe’s rear seats are more comfortable. The car body does not move unnecessarily while passing bumps, and, thanks to the damper’s improved resilience, the car’s cornering stability has become better as well. Finally, the rod diameter increase has also led to improved stability at high-speed driving.

The new Santa Fe underwent meticulous geometry adjustments to ensure stable cornering.

There were also geometry tweaks on both front and rear suspensions, resulting in the higher roll center. The roll center is defined as the intersection between (1) the vehicle’s center-of-gravity line (A, as pictured above) and (2) the line between the point-of-contact between the tire’s vertical centerline and the ground (Y) and the lower arm extension line (Z). A hypothetical line between the front and rear roll centers is called the “roll axis,” and the car’s tilting phenomenon during cornering occurs with respect to this roll axis. In ordinary circumstances, the higher the roll center, and the closer it is to the vehicle’s center of gravity (which is typically located higher than the roll center), the less severe the roll and the tilting issue, leading to a more stable cornering. This is why the new Santa Fe has adjusted the suspension geometry to move the front and rear roll centers up (2mm and 8mm, respectively) to 119mm and 179mm. Thanks to these changes, the new Santa Fe’s cornering performance is better than ever.

Brand New NVH (Noise, Vibration & Harshness) Countermeasures

Even minor noise and vibration can cause discomfort to not only the driver but also the passengers. For relatively short rides, these problems may be ignored, if only temporarily—but for family cars like the Santa Fe, persistent noise and vibration problems must be addressed. To this end, the new Santa Fe comes with brand new NVH countermeasures.

The front subframe now comes with hydro bushes that suppress booming noise and vibration.

First, the noise from accelerating was suppressed by increasing the thickness of the sound absorption pad ironside the dashboard. Likewise, the vibration coming over from the engine room was suppressed by applying hydro bushes to the front subframe. The new bushes work to attenuate vibration at select frequencies, in effect minimizing the booming noise and residue vibration. At the same time, the rubber on the engine mount was switched to high-stiffness rubber, further decreasing the vibration from accelerating.

Finally, the vibration delivered from the road surface was reduced by changing the chassis and car body structures. More specifically, the parts on the lower panel that are particularly vulnerable to NVH received stiffness increases, thus minimizing the mid/low-frequency noises delivered from the ground, via the tires and the suspension, to the cabin.

System Improvements Lead to Better Brakes

For mid-size SUVs and above, braking performance has to be considered as important as the more heralded aspects of car performance; after all, cars in this segment do not have many opportunities to run fast and aggressively. They mostly run with many passengers and cargo on board, true to the label of “family car.” That’s why the engineers worked hard to improve the brakes on the new Santa Fe—and thanks to the across-the-board improvements on the brake system, the model now boasts the most stable and most powerful brakes in its long model history.

The increased diameter of the brake booster, making for a higher capacity, leads to a highly responsive brake feel.

The most pronounced change on the system is in the brake booster—a mechanism that boosts the force applied by the driver on the brake pedal and sent to the brake calipers. The new Santa Fe increased the brake booster’s diameter from 10.5 inches (266.7 mm) to 11 inches (279.4 mm), which helped create a quicker and more responsive brake feel.

The new Santa Fe Hybrid uses IEB (Integrated Electronic Brake). The 4th-gen Santa Fe used a traditional booster system with separate pressure generator and pressure controller—whereby high-pressure oil is transferred to the calipers with the help of the engine’s buoyancy—to apply the brakes. In contrast, new Santa Fe Hybrid’s IEB uses the motor to create sudden pressures and, in part thanks to this structure, integrates the pressure generator and controller into a single system. IEB’s brake pressure now stands at 850 bar/s, far stronger and quicker than that of the 4th-gen Santa Fe (650 bar/s). In essence, these figures mean that the same push on the brake pedals will result in stronger and faster brakes in the new Santa Fe.

The 2.5 Turbo model has increased the size of the front disc, increasing the brake performance commensurate with the performance increase.

The front brake disc, arguably the single most important part in determining brake performance, also underwent a size increase from 320 mm to 325 mm. The equivalent disc on the 2.5 Turbo model, which boasts max power of 281 hp and max torque of 43.0kg·m, comes with a larger 345 mm diameter; an increase in brake performance was needed to counterbalance the increase in vehicle power.

3rd-Generation Platform a Foundation for Improved Collision Safety

With the application of the 3rd-generation platform’s multi-load path structure, the new Santa Fe’s collision safety underwent a drastic improvement.

But by far the biggest internal change of the new Santa Fe is the platform upgrade—with the application of the 3rd-generation platform, the model received across-the-board performance increases. Particularly noticeable is the increase in collision safety performance; even in the previous generations, the Santa Fe line boasted top-of-the-line collision safety marks, but the new Santa Fe’s collision safety has evolved even a step further. The crux of the change is the front-wheel subframe’s H-shaped structure, which has changed into a sharp-shaped(#) one. The resulting multi-load path structure diversifies the pathway of shock loads, distributing external shocks evenly and reducing the shock conveyed to the passenger.

Moreover, by simplifying the structure of the crossmember—the component bolted on the underside of the car body to support the engine and the transmission—the engineers could increase the proportion of hot-stamping steel sheets with high tensile strength applied to the lower body, which also led to general collision safety improvements. The stronger hot-stamping sheets are applied to the A-pillar, B-pillar reinforce, side-outer reinforce, inside of the side seal, and front-side member lower.

The New Terrain Mode: Off-Road State of Mind

The new Santa Fe comes with a feature that one could not find in the previous versions of the model: the Terrain Mode. Now a staple of the modern SUV, the Terrain Mode allows the vehicle to smoothly traverse off-road conditions. The application of this technology on the Santa Fe reflects Hyundai’s wishes to provide a safer and more comfortable journey for the touring family.

Families on a trip can take advantage of the Terrain Mode for a more comfortable journey.

The Terrain Mode is composed of three sub-modes: Snow, Sand, and Mud. Each mode comprehensively adjusts and controls the engine, transmission, power, and brakes to better suit the respective road conditions. Whereas cars without the Terrain Mode are prone to slippage or sinking in the snow or mud, the new Santa Fe is without such concern. Simply turning the Terrain Mode Dial will let the Santa Fe take care of the road issues, and the driver can simply drive as he normally would. The ride will feel as comfortable as one on asphalt.

Suppose you are on your way to a family campsite, traversing through the woods on unpaved roads that have been wetted by last night’s rain. These muddy roads, though, are no match for the new Santa Fe. Set the terrain dial to the Mud Mode, and the vehicle will keep the wheel RPM at higher levels than usual. This is done by delaying the gear shifts of the transmission as much as possible as well as changing the response to the gas pedal, which leads to an artificial generation of a higher-than-usual engine RPM. The fast-rotating wheel works to instantly remove the mud adhering to the tire. The mode also balances the power delivered to the front and the rear wheels at 50:50, allowing the Santa Fe to powerfully jump out of the mud.

The Terrain Mode allows the Santa Fe to traverse a variety of harsh terrains.

The Sand Mode works quite similarly to the Mud Mode; gear shifts are delayed as much as possible, and the engine RPM is set higher than the usual. But as too much power on the wheels can make them sink into the sand, the power delivery in the Sand Mode is a bit subtler and more delicate than that in the Mud Mode.

The Snow Mode begins from the well-founded assumption that sudden delivery of power onto the wheels causes slippage on the snow. As such, when a car starts under the Snow Mode, the transmission automatically begins the car at the second gear, and even hard-pumping the gas pedal does not spike the engine RPM. The gear shifts are made quicker to assure soft and consistent delivery of power onto front and rear wheels. Because the mechanism works well on other slippery terrains (wet pebbles or dewy grass), the Snow Mode need not be limited to snow.

Santa Fe’s performance evolution paves the way to its ultimate objective: becoming the ultimate family SUV.

As seen, the new Santa Fe’s evolutions are very much varied; though technically a “facelift” model, the new Santa Fe has achieved significant performance improvements that one might expect in next-generation models, across such a diverse range that includes the suspension, brakes, collision safety, and off-road capabilities. But these upgrades should not surprise us; after all, these performance evolutions are simple manifestations of the model’s age-old objective—becoming the ultimate family SUV.