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Thanks, WRC, The Chassis Technology Developed by Hyundai

Various evaluation agencies and media outlets around the world highlight the agility and ride quality of Hyundai Motor Company's mass-produced vehicles. And here is the story behind it - how Hyundai developed its chassis technology through WRC.

There are many qualities to be a good, decent car. You can’t just pick one – it requires nice design, various convenience features, and a comfortable cabin. But there is one indispensable thing; it has to feature excellent driving performance. To do so, there are several criteria that a good car has to meet. It has to be powerful enough, spin, stop well, and comfortable to ride. Of course, it’s not easy to satisfy all these at the same time. However, the latest model of Hyundai meets quite many of these. This is why various evaluation agencies and media around the world are paying attention to Hyundai.

It was hard to expect such a response from Hyundai more than a decade ago. In other words, dramatic changes have taken place in just a few years. One of the reasons for this change was Hyundai’s participation in the WRC. As we saw in the past two WRC technology internalization contents, the mass-produced cars made after Hyundai returned to the WRC reflect various motorsports technologies and know-how. Among them are chassis-related internalization, which has had a lot of impact on agile driving performance and smooth ride.

Go To: Hyundai Houses WRC Techs For Better Understanding On Their Products

Go To: Namyang Executives’ Perspective on Why Hyundai Is in the WRC

Jung Jin-ho, a Senior researcher at the institute, says his experience in designing a World Rally Car based on a mass-produced car helped improving the chassis performance of a high-performance car.

Of course, behind these results are numerous researchers who have worked to develop World Rally Cars and at the same time internalize their technology and know-how into mass-produced cars. We met one of the researchers, Jeong Jin-ho, a Senior researcher at the Total Chassis Concept Engineering Design Team, and talked about the internalization of the mass-produced car of the World Rally Car chassis technology.

Q. Looking at the exterior or chassis structure, the World Rally Car and the high-performance Hyundai N are similar. I wonder what kind of relationship there is between the two.

The first thing to note is that the WRC has more restrictions than other motorsports. The prerequisite that it should be based on mass-produced vehicles is followed, and the scope of modification is limited. For example, the International Federation of Automotive Engineers (FIA) restricts the suspension type of World Rally Cars and the range of changes to the mass-produced vehicles of the wheelbase, electric field, and body, and also limits the chassis mount points to within 20mm of mass produced vehicles. Therefore, in order to achieve good results in the WRC, the basic specifications and structure of the mass produced cars, the basis of the race cars, should be good enough.

During the process, we learned things that I had never known before. While designing a race car based on the mass-produced car, the shortcomings of the mass-produced car caught my eye. When developing the next generation of mass-production cars, I knew how to improve these areas, and even realized that this process could improve the performance of race cars. To sum up, the feedback generated from the existing WRC Rally Cars was reflected in the next generation of mass-production cars, and based on this, a new World Rally Car was created. If the skills used for the mass-produced car, which is the basis of the race car, are not good enough, we couldn’t make a decent high-performing race car.

Similarly, since high-performance N models are also the successors of the basic mass-produced vehicles, improvement and development are carried out based on mass-produced vehicles. In other words, the company is using first-generation N models to share experiences and technologies in developing the next mass-produced models. Then using those, we get to develop even better second-generation N model.

The i20 was the cornerstone of the i20 World Rally Car and contributed dearly to the performance improvement.

Q. I would like to know the specifics regarding the internalization process.

I would want to talk about the new i20 WRC rally car in 2016. Based on various feedbacks from the initial i20 coupe WRC rally, the company made the second-generation i20 mass-produced cars, and based on this, it produced the new i20 WRC rally car again. The performance difference between the first-generation i20 coupe World Rally Car and the second-generation i20 World Rally Car has improved noticeably. Drivers could feel the difference for themselves.

But when I returned to the WRC in 2014, I couldn’t think about these things when I developed a race car, because there was no experience and data. I learned a lot while continuously developing a race car. In the process, chassis internalization techniques related to durability and stiffness were achieved greatly.

Q. In order to achieve solid driving performance like you said, the chassis should be strong. Then is there an example of the internalized WRC technology?

The experience and technology of building a WRC Rally Car were of great help when strengthening the axle, the part that connects the wheel/tires. There is a good reason for strengthening only the stiffness of the axle, among many other parts of the chassis. This is because the stiffness of the axle alone can greatly improve driving performance. Based on the experience of designing race cars, the company conducted designs to secure rigidity from the stage of setting axle specifications of high-performance cars to the stage of tightening structures and shape design. As a result, chassis stiffness could be greatly improved enough to withstand the strong lateral forces in the circuit. In the early stages of R&H development, the geometry variable knuckle structure being applied to WRC Rally Cars is utilized, so that suspension kinematic properties can be set.

Q. Is there another case of WRC technology internalization in relation to axle technology?

There is the world’s first Integrated Drive Axle (IDA) developed in January last year. The technology is a combination of a drive shaft and wheel bearing that transmits engine power to the wheels and is applied to the i20 coupe WRC Rally Car. We are currently working on applying this technology to mass-produced cars, and considering introducing it into the next-generation high-performance models.

Mounting technology was applied to high-performance mass-produced vehicles to enhance the strong axle strength and directness of WRC Rally Cars.

Q. Besides strengthening axle rigidity, what are some things in internalizing WRC technology in other criteria?

The high-performance N model strengthened the rigidity of each part where the powertrain and chassis are connected to the vehicle to improve reaction speed and direct connection. The World Rally Car engages all parts of the powertrain, chassis, and body connections with solid mounts or ball joints. This is because acceleration, deceleration, and steering operation require the driver to respond immediately within the required time. On the other hand, the basic i30 or Veloster applies a rubber-like bush mount to each connection. This is because they are developing cars with more emphasis on maintaining ride comforts such as shock mitigation and vibration insulation. The high-performance N model secured sharp control and a direct connection without significantly damaging ride quality and driving vibration by selectively applying rubber bushes and solid mount types to the areas with the greatest performance effects respectively.

The braking technology of a high-performance mass-produced vehicle does not directly use the WRC’s technology.

Q. Is there braking technology internalized? Considering the powerful brakes of the World Rally Car, it looks like internalization could have been achieved.

The implementation of the braking technology borrowed the idea from the cooling technology rather than from the system itself. First of all, World Rally Cars use brake pads or discs with high-coefficient of friction to improve braking performance. Inspired by this, the i30 N and Veloster N also increased brake disc size and strengthened the friction of pads. However, it did not apply the technology of the race car. This is because it is important for mass-produced cars to have reasonable prices that do not require that much performance and are not burdensome to purchase. Instead, high-performance mass-produced vehicles are internalizing other technologies to improve braking performance. This method cools the brakes with ‘cooling duct’ and ‘air guide’.

One of the techniques inspired by the World Rally Car is the “Pre-Fill” brake control technology. The technology began with the idea that fast acceleration and deceleration of race cars and harsh braking may be necessary for high-performance mass-produced vehicles. The “Pad Recognition Sensor,” which can effectively manage brake pads in circuit driving, where braking performance reaches its limit, is also a technology inspired by the image of a World Rally Car that replaces pads at every competition.

The dampers or springs of the World Rally Car can be brought to the mass-produced car, but that will make it too expensive.

Q. Generally speaking, internalizing the suspension technology of race cars is easy to think of the damper or spring side. Is there any internalization of technology in the components involved?

Instead of applying immediately, the technology in the damper and spring is developing the idea further by considering the structure and performance weight or price that are suitable for applying to mass produced vehicles. There are many reasons. First of all, high-performance mass-produced cars such as i30 N and Veloster N, where WRC technology is most embedded, are C-segment hatchbacks. Among these cars, it would be simply ‘overdone’ to use the high-performance dampers and springs of the WRC Rally Cars for those. The stiffness of the axle mentioned earlier alone can be sufficiently high performing enough.

Of course, adding the damper and spring of the race cars will give you much better driving performance. But the price rises significantly as well. It has not attempted to internalize damper and spring technology to make our consumers happy. I wanted to provide high-performance cars with built-in motorsports technology at a reasonable price so that more people can enjoy them.

IDA integrates driveshafts and bearings into one, increasing stiffness and reducing weight.

Examples of High-performance Mass-produced vehicles with WRC technology Embedded

Here are more specific examples of the internalization of WRC technology mentioned in an interview with Senior researcher Jung Jin-ho.

1. Integrated drive axle (IDA) of high-performance mass-produced vehicles

Until Hyundai developed the technology for the first time in the world, all cars connected drive shafts and wheel bearings like bolts and nuts to power the wheels. There was a problem; power loss, weak rigidity, and heavy weight due to a large number of parts. On the other hand, IDA has about 59% more rigidity and about 10% less weight than before due to component integration. In addition, the defect rate of parts manufacturing also decreased significantly.

High-performance N models are equipped with cooling ducts (i30 N) and air guides (Veloster N) for better cooling the brakes.

2. Braking technology of high-performance mass-produced vehicles derived from WRC Rally Cars

Cooling ducts are air passages from the inlet of the front bumper to the inside of the wheel arch where the brakes are located. Cooling efficiency is maximized because cold air that touches the front of the vehicle while driving directly flows into the hot brake. Air guides are also slightly different in shape, but their principles and effects are not so different from cooling ducts. If you apply cooling ducts and air guides, you can have the same effect as expanding the brake disc by about 30mm. It also has the durability that allows users to drive a circuit for a long time without tuning.

The Pre-Fill function greatly improves braking performance without the driver knowing it.

Pre-Fill is a technique in which the system detects in advance the driver’s brake application during harsh circuit driving and pre-loads hydraulic pressure to increase braking performance and response speed. Although it is not a technology applied to World Rally Cars, it was developed in anticipation that rapid acceleration and deceleration could be repeated like WRC Rally Cars in high-performance mass-production vehicles.

The upcoming high-performance N model will be equipped with a brake pad recognition sensor to help maintain excellent braking performance.

The i20 N, which will soon be revealed, will have a brake pad recognition sensor. The brake pad recognition sensor is a technology inspired by the image of a World Rally Car replacing the brake pad in every game due to harsh driving conditions. The recognition sensor of the high-performance mass-produced vehicle sends an alert to the driver when the brake pad is less than 4mm left, to inform how many more laps the remaining pad could go. This will prevent the driver from completely worn pads, maintaining excellent braking performance.