Locally-tuned chassis: What does it mean?

If you've read any Hyundai reviews on these pages in the past few years, you'll have no doubt seen the words 'locally-tuned chassis'. It's a short phrase, but one that simply doesn't do justice to the depth of knowledge and amount of effort that goes into ensuring your next new Hyundai feels at home on Australian roads.

Hyundai isn't the only manufacturer to subject its cars to a rigorous chassis localisation process Down Under. In fact, it's become a new battleground for the nation's three remaining car-makers, who all make big claims about the level of local engineering that will be applied to their imported models once Australian production stops at the end of 2017.

However, Hyundai has spent vast sums of money in the tuning of its vehicle suspension and steering systems to suit Aussie conditions, and the significant investment has paid dividends for its buyers and -- presumably -- Hyundai itself.

Observing the maturing of the Korean car-maker's ride and handling compromise from a critic's viewpoint, the difference in the past decade alone is as obvious as night and day.

To find out just what's involved in tweaking a new car for Aussie roads, we joined Hyundai's vehicle dynamics consultant David Potter for a ride-along in the upcoming Elantra SR.

Tell us a bit about yourself. What is your background?
DP: Before working in motorsport, I came from an agricultural engineering background. From there I went on to develop chassis for BMW (including the E36 3 Series) and Subaru before setting up my own business in 1996. Initially, that focussed primarily on motorsport – everything from rally cars to Indy cars – but has progressed to road cars and even military vehicles.

How long have you worked with Hyundai ib Australia?
DP: I've been involved with Hyundai for just over three years. It all started with HMCA asking for a little advice on a few things, and by 2013 we were running the simulator over a few cars and tuning the chassis for local roads.

How many Hyundai models would have been through the localisation process?
DP: We've tuned 12 or 13 models now. Increasingly, we're involved from earlier in the development process, and we're now at a point where we're fairly heavily involved in every new Hyundai model sold here.

Can you tell us what Hyundai believes Australian drivers want from a chassis?
DP: Australian drivers tell us they want a car to have good body control, a sporty, well-controlled -- but not rigid -- ride; and yet one that is still comfortable. It's a pretty demanding mix, really. I try to think of the car handling the wide variety of road conditions we have here. The car has to be competent in all conditions, and should never get to a point where's it's too harsh or out of control. The ride has to be in phase front to rear, and that's important in maintaining control, especially on dirt roads. All cars need a percentage of control over comfort – and that's Hyundai Australia's DNA, if you like. It's a character that's dictated by our customers, and something we've certainly established over the course of tuning cars for local conditions. There's certainly continuity across the Hyundai family now.

Do some models warrant more tuning than others? Or do sports models like the Elantra SR require more work?
DP: Vehicles with a higher GVM (Gross Vehicle Mass), such as those that can be expected to carry a load or tow frequently, and performance models like the Elantra SR we're in now, typically require more work. In the case of the former, it's because the vehicle is often expected to perform across not only a wider variety of roads, but also while loaded, unloaded or somewhere in between. It's important that the vehicle feels predictable regardless of the weight it's carrying. For sportier tunes, we find our customers are generally more discerning of the ride/handling compromise, and it's important we deliver on their expectations while staying within the range of our DNA.

How long before the start of production does the localisation process take place?
DP: There have been a couple of vehicles we've been invited to develop from a very early stage. Sometimes it's just to troubleshoot a specific problem, and it's nice to have an engineering team ask your opinion on such matters. More often, though, we see the car a few months before it's due to go on sale.

Does head office give you enough information to get the job done?
DP: We actually get very good access to information, and we make the most of the information we get. Of course, we'd always like a little more time [to develop our tune], but in saying that I've also worked for manufacturers who've supplied a lot less information and offered a lot less time. Hyundai now seems to understand that the more information you get, the better the result is. I'm very pleased with the information we're now getting.

You say 'now seems to understand'. Was that not always this way?
DP: Initially head office asked: "Why do you actually need to do that?" But they've come to appreciate why we take this avenue. Once HMC engineers came to Australia and experienced the wide variety of road conditions we have, they understood very quickly the 'why' of our work. Those that are not accustomed to Australian road conditions can't necessarily see the benefit of a localised tuning program. Now they say: "Yes, we understand why you've tuned the car this way".

How long does it typically take to tune a car to Australian conditions?
DP: It can take anywhere from three weeks to two months, depending on how close the tune is to our specifications to begin with. That said, we like to give each car the same amount of time – and the opportunity to experience that car on the variety of test roads we use in assessing vehicles for local conditions.

How many permutations of tune would you work through in this time?
DP: It depends on the target of our builds. Usually we'd go through 15 to 20 front permutations and 30 rears before we get a result. Though in some markets – those we enter without the simulation – we can go through as many as 40 fronts and 60 rears before we get it right.

Do you benchmark competitor vehicles when tuning Hyundais for local roads?
DP: Of course, but only the good ones.

Can you tell us which these might be for the Elantra SR?
DP: We drove a range of cars, but we felt many were too sporty, or simply not sporty enough. You could say the Mazda3 SP25 is a rival we're looking very closely at for the Elantra SR – both in terms of performance and ride/handling. We also benchmarked the Audi A3 sedan. We're not aiming to replicate the [suspension] performance of the rival cars – we seek to understand the competitor vehicles' capabilities, then work toward exceeding them while at the same time keeping the character or DNA of our cars.

So you also use the data from the dozen or so models you've developed so far?
DP: Indeed. All of this is overlayed with a great deal of data from other cars – mostly our own, of course – travelling over the same roads at the same speeds. As we progress, and collect more data from our ongoing work, we learn more about how to get the best out of any car. I don't think any of the engineering team would say they don't learn anything on any new tune. We're constantly learning.

Does that 'learning' mean you might change the roads you use to assess your cars?
DP: It's an evolving process and we now have a mass of data to call upon. The roads we choose are incredibly varied and sometimes extremely challenging, including the worst kind of washboard gravel, for example. The cars get a tough time, but hopefully the end result is worth the effort.

We joined David for a several test loops in the Elantra SR, first sampling a torturous urban circuit, then a longer outer-urban course with challenging twists and turns. Each time, David placed the wheels at the exact same point of the exact same bumps at the exact same speed, continually feeling the car's performance, and occasionally stopping to make notes.

At the end of each loop, we'd return to Hyundai's Sydney HQ and compile the notes gathered in real-time from his simulation software for the review of his engineering team. Discussing the cause and effect of the most recent changes, the team then collaborated with a representative from Mando [the damper supplier for the Elantra SR and other Hyundais] to change damper (and any other component) settings, before fitting them and driving the same loop again.

Impressively, and even from the passenger side of the car, it was obvious how slight changes could affect the car's performance in certain areas. Where the car had touched its nose previously, it no longer did. And where it was too stiff or firm, it was softer on subsequent runs.

The simulation software you developed, can you tell us a bit about that?
DP: We are fairly unique in that our localisation program includes a data acquisition program, and that's very important. We're probably one of the few importers to use the data acquisition software in conjunction with the tuning process. Most seem to do it via the traditional "seat of the pants" method – and that even extends to manufacturers on their proving grounds.

Is it a difficult process?
DP: There are a lot of times where, even with the data, it can be very hard work; and using the performance analysis tools allow us a great insight into what's occurring in the dynamics of the vehicle. It's all maths at the end of the day, and it really helps us to pick up on those details you can otherwise miss. The simulation is a very important part [of the tuning process], and I have to stress that quite heavily. But sometimes we do travel to Namyang (Hyundai's R&D base in Korea) and sit with the engineers to review certain components, and that's another big bonus – that we have that level of input.

What can the simulation detect that a specialist driver may not?
DP: Often the objective analysis shows that what we actually feel isn't the root cause, and that the cause is actually due to another influence. Quite often what we are feeling is the after-affect or reaction of it. So data acquisition is actually very useful for targeting the root cause of the problem, rather than trying to tune something – possibly even in the wrong direction – because we're tuning the after-affect rather than the root cause.

Do other Hyundai markets undertake similar localisation programs?
DP: Yes, of course. Some have their own design, manufacturing and testing facilities as well. And there's a degree of shared information between us. What's really interesting for us is that some markets have taken our tunes completely, and found they've worked very well in their own market. Others have used our tunes as a starting point, and it's been quite interesting to see some of the feedback we're getting; it's very positive. However, it's also certainly true that some countries do focus on their own, perhaps limited, sections of roads too much; and they probably make a very fair job of tuning the car for those conditions. But we've got a far wider variety of conditions to consider.

Australia has a large percentage of poorly maintained and unsealed roads. Is there an emphasis on making the suspension work away from the 'A' roads?
DP: Yes, definitely; and I'm absolutely passionate about getting that right. We've assessed our cars on a variety of roads – the types of roads you'd expect more than 80 per cent of the population to encounter on a daily basis – and driven lots of different areas of the outback and on remote roads as well to experience as many different road surfaces as we can. It's vital we can readily interpret and understand those road characteristics our customers experience, and make the car's suspension work. In short, a car tuned well in those conditions will work pretty much anywhere.

Hyundai Australia sources cars from Korea and Europe. Is there a difference between them?
DP: When taking cars from different plants – as you say the European factory and the Korean factory -- we find there are different kinematics and different hard points [the points where the suspension attaches to the car's body]. But it's also the fact there are two- and four-wheel drive variants, sometimes as many as three wheel and tyre sizes, and often different engines and transmissions that can influence the tune. Even the suspension itself can come from two different suppliers [Sachs and Mando]. Obviously that's a lot of different variations to consider when you're trying to tune a car to offer a similar feel and response to the driver.

So is it just suspension and steering components that are 'tuned'? Or do you look at brakes, bearings and mounts as well?
DP: We only change brakes and bearings on special models, like the Santa Fe SR, as an example. If you start changing the brakes, it's only ever in conjunction with head office, because then you need to start rewriting the code for the stability control systems, anti-lock brakes and so on. This then becomes a fundamental change of the vehicle's character, and as it is one that impacts various safety systems [electronic driver aids], it needs to be validated by head office. We may do the validation on it [the re-written software], but our market is too small to dictate special components in that way. For the Santa Fe SR, the finished overall item is an Australian product, but head office had previously considered the [Brembo] brake package as an option, and we married that with a suspension tune to come up with a unique model.

You mentioned stability control and anti-lock brakes. Are the parameters of these systems altered by the suspension localisation process?
DP: What we deliver is mainly a ride frequency tune. As such, we're staying within the tolerance band of the electronic driver aids. If the calibration is pretty good, and you're not moving the parameters too far out of the vehicle's range, it's not an issue. In fact, if you've done everything right, you're making fewer demands on the stability control because you're actually making the vehicle more neutral, and giving the stability control less need to interact.

Can the tune affect other elements of what we feel in the cabin? Road noise, for example?
Broadly, road noise is very much about the road surface and the tyre. But you can change the way the acoustic is carried through to the cabin by the damper tune. It's those types of details that are quite demanding work. Trying to achieve a quieter ride without sacrificing anything else is very difficult indeed. What we aim to achieve is the nicest blend without sacrificing ride. [Suspension] performance and noise are not mutually exclusive, but they're not altogether compatible either.

Is it a costly investment to tailor a chassis tune to a specific market?
DP: We don't share precise cost numbers, but yes, I guess you could say it's 'costly' compared with not doing it at all! But the value in it for customers more than makes up for the cost, in our opinion.

Is the investment worth the outlay?
DP: It's very much worth the outlay, because it's of real benefit to customers no matter where they drive in Australia. Their car is tuned and honed by Australian engineers and Australian drivers on Australian roads, and our suspension tuning team have a very deep understanding of what needs to go into any type of car to cope with our unique conditions. And it's important to remember that our parent company in South Korea supports us with the extra complication and expense of bespoke Australian suspension fitted on the factory lines. Our management really appreciate and understand the benefits of this investment, and it's great to see.

At the end of our day with the engineering team it was obvious the tune of the Elantra SR had evolved, although Potter was quick to add: "It's still a work in progress".

Hyundai is expected to release more information on its sportier Elantra soon. We look forward to assessing the car on its local launch soon to see the results of Potter and his team's work.

Stay tuned for more soon.