Wants and needs

24 March 2022

Australians have always been innovative. This is particularly so in the automotive industry. Given the size of our population, it’s remarkable how many manufacturers of automotive aftermarket products we’ve had over the years, and still have. ECU systems come to mind as one example and you’d have to add dynamometers to the list.

A number of dyno manufacturers have come and gone over the years. The lack of any new Australian manufacturers in recent times might be taken to be an indication that there’s no room for another. Melbourne company Dyno Innovations disagrees. The founders of this new company have been selling and developing chassis, engine and hub dynos for other companies and organisations for decades. They’ve also been using them for just as long. Now, they’ve decided to make their own, so Australasian Automotive (AA) paid a visit. Their assessment that there is room for another manufacturer has proven correct. Who’d have thought?

With such well-established local manufacturers like Dyno Dynamics and Mainline/DynoLog producing high-quality products for decades, it doesn’t seem possible. Yet AA has seen confirmation that it is possible on the orders/progress board in production. Many workshops have known the value of dynamometers for years and already have one. A good number have even upgraded to their second machine. Others, though, have felt they didn’t need one. They’ve been of the opinion that street tuning gives them everything they need. Some still hold that opinion. They argue that street testing is a more realistic diagnostic and tuning method because that’s where a car is going to be driven. However, this is an outdated attitude that’s gradually passing away.

A modern chassis dynamometer is seen by workshops that have one as an indispensable tuning tool capable of virtually anything a tuner could want to do. Not many workshops buy a chassis dyno and then leave it in a corner unused. Apart from operational versatility, there’s the benefit of not taking customers’ cars out on the road where all sorts of unfortunate things can happen.
Dyno Innovations said they were talking to a potential customer who had the old attitude. He was tuning a performance street car and things went horribly awry. The end result was a lot of expensive damage that the workshop had to fix. Shortly after, the owner bought a dynomometer. True, performance tuning on the street shouldn’t have taken place to begin with, but even with sedate run-of-the-mill testing things can go wrong. So, the two main reasons for getting a chassis dynamometer are its extreme usefulness and the reduced likelihood of damaging customer cars.

Of course, a dynamometer is an expensive acquisition. A two-wheel-drive unit is usually around $50,000 to $60,000 with a four-wheel-drive version costing about twice that. But they’re most usually purchased using finance, which makes the financial outlay much more manageable. Independent finance specialists usually handle the details rather than the manufacturers themselves. What’s more, the fact a dynomometer is expensive can indicate to your customers that your business is prosperous enough to afford one. Problems can often be solved much more quickly with a dyno than without one, which leads to improved customer satisfaction. In turn, getting work done more quickly and more effectively leads to increased turnover and, of course, more profit.

Dyno Innovations explained that the market for dynos has changed over the years. A couple of decades ago, it was all Fords and Holdens with the occasional Japanese car. Now, there’s a much wider variety of cars being diagnosed and tuned, like Rangers, HiLuxes, diesels, etc. Linked front and rear roller beds are important because even some 2WD cars can’t be tested unless all the wheels are turning. Some cars with this requirement don’t have dyno modes and you can’t take tailshafts out, so there’s nothing that can be done. Linked beds are the only solution for such models. In the past, a good many dynos were used mainly for power runs at wide open throttle. Such testing results in pretty graphs that show where maximum power and torque occurred. Because power runs are made at wide open throttle there isn’t much that can be checked except perhaps mixtures at full power. This is the so-called ramp run but it’s a limited way of thinking about dynamometers. A car may run perfectly at wide open throttle but cars are rarely driven that way. 

Steady state testing and tuning on the other hand occurs at particular revs and loads. It’s much more useful for getting a car to run properly right throughout its rev range. This is the very definition of driveability. Steady state testing also allows an operator to zero in on a problem that only occurs under particular conditions. It can also be used to tune for specific circumstances, all while the vehicle stays in the workshop. One race team got a dyno just to tune for coasting down the hill at Bathurst. The idea was to trim the fuel under those conditions so the car might get an extra lap or two from each tank of fuel. Now that’s what you call specific.

While roller dynos simulate road conditions they can only do so if the rollers offer a surface that emulates road grip. The pattern cut into the rollers to offer such grip is important and throughout the history of the chassis dyno all sorts of patterns have been tried. Standard knurling didn’t work that well and used to shred tyres. Now, long grooves with particular profiles like those shown have proven to be the most effective. However, even these have their limits. If a vehicle has too much power the tyres will exceed the available grip and the tyres will start to turn faster than the roller. This is known as slip and it obviously effects the accuracy of the data gathered by the system. Such slip has to be eliminated, which brings us to hub dynamometers.

The most effective way of eliminating slip is to remove the wheels and bolt the dyno directly to the hubs as shown. As cars have become more powerful hub dynos have grown in popularity and continue to do so. Also, many track cars, particularly high powered drag cars, can be tested on hub dynos in any gear and at any speed. This is completely impossible with roller dynos. However, it’s not just track cars that benefit.

Many workshops are choosing hub dynos for their general tuning work. There’s no doubt a roller dyno is easier to use but many more powerful cars have to be firmly tied down to hold the tyres in the rollers properly, and this takes time. Hub dynos aren’t that difficult to set up and like anything, the more it’s done the easier it becomes. Some businesses are replacing their roller dynos with hub units but others are keeping both types to retain the advantages of each.

Dyno Innovations said there have been about 4,000 dynos sold in Australia. So, is that it? Is the market close to saturated? No. In Victoria from Warragul in the east, to Werribee in the west, to Campbellfield in the north, there are about 5,000 workshops. In a similar region around Sydney there are roughly 10,000 workshops. These numbers have been constant over the years. One may close but another opens. So, in the two states that’s about 15,000 to say nothing of the rest of the country.

This begs the question, why aren’t there more dynamometer manufacturers?

From an engineering perspective, dynamometers aren’t that complicated. However, designing and manufacturing one is much more than simply copying the dimensions and locations of components. If a potential manufacturer didn’t understand the market, didn’t know how to tune a car and had to learn about things like OBD2, rich and lean mixtures and any number of other things related to automotive technology, they simply wouldn’t be able to manufacture a dynamometer successfully. Nor would they be able to sell dynos into the local market. The team at Dyno Innovations has this expertise built in. We must also say that the other Australian and international manufacturers also have such expertise.

Dyno Innovations is a new company. Operations were just getting under way when COVID hit in 2021, which imposed difficulties. It definitely wasn’t the ideal time to start a major manufacturing business. In the end, though, the company pushed through. The original notion was to source everything locally and to build everything locally. Nice idea but wholly impractical in today’s manufacturing environment. For instance, there are no locally built eddy current retarders, so these have to be imported. There are other components available locally but upon further investigation such components are discovered to be manufactured overseas and then imported by local suppliers. So, not Australian made.

There’s also the price difference between imported components and locally manufactured versions. Dyno Innovations found, in the case of one major component, the cost of the imported version was just one per cent of the price for the local unit. This added up to a decent handful of thousands of dollars cheaper for each unit. The catch is that imported components have to be purchased in greater quantities than a local manufacturing operation might be able to handle. For the item mentioned above, the minimum order was a thousand units. This was far too many for Dyno Innovations’ needs. They asked if they could get away with 50. The supplier said they’d be willing to do a hundred. So, even quantities can be bartered. We should also point out the engineering support from this supplier was superior and the upgrades suggested by the offshore engineers were included at no extra cost. Dyno Innovations was a bit vague about the details of the product mentioned above for trade secret reasons but the example makes the point. 

On the other hand, everything that can be manufactured here is. The chassis, rollers, bearings, shafts and other hardware components are made here and the company is adamant they always will be. Both the roller and hub dynamometers from Dyno Innovations are built around eddy current retarders. Almost everyone in the trade knows these work by means of magnetism. Often, though, that’s about as deep an understanding as an operator has. However, the details are interesting for those more curious.

When an electric current flows, it creates an electromagnetic field around the conductor through which it passes. Importantly, an electromagnetic field generates current in any conductor that passes through it. So, the initial electromagnetic field creates a current and then that current creates a second electromagnetic field. This is the back-EMF mentioned in discussions about electric motors, transformers and the like. In these applications it is undesirable. In eddy current retarders it is essential.

In 1834, physicist Emil Lenz discovered that when a magnetic field (the initial field) induces current, the field created (the second field) by that current opposes the force from the initial field. This resistance between the initial and second electromagnetic fields is how an eddy current retarder creates a drag/load against which a drivetrain has to work.

As the photographs show, there is a ring of powerful electromagnets around the periphery of each retarder. Iron rotors set very close to the ends of these electromagnets turn through the fields created by the magnets. This induces current in the rotors. Because such current has no circuit through which it can flow, it turns in circles/rings, like eddys in water. So, to repeat, the fields created by these eddy currents oppose the fields that created the eddy currents in the first place. The strength of these fields is varied by altering the current passing through the electromagnets, which varies the load against which the drivetrain works. This brings up the matter of dynamometer control.

The user interface of the Dyno Innovations system occurs through a wireless keyboard. Operationally, the control system is designed so any action can be performed with the minimum number of keystrokes. Four is the maximum for any action. There’s a screen interface as with all modern dynamometers (they used to have big mechanical needles and dials). However, that’s just a basic description of high level control. At the deeper, lower level there’s more going on.

The control system for a dynamometer has to be as responsive and precise as possible. Achieving this requires the balancing of certain parameters. Two of the most important are the speed of the settling time (at the target speed) and overshoot. When a speed is set and the throttle opened the controller should manage it with minimum overshoot. However, eliminating overshoot can mean the controller will be slower. But a faster controller may result in oscillation, which is the very definition of an unstable controller. Balancing these and other parameters for the wide range of cars that will be tested on an average dynamometer is the challenge. As with all engineering problems, it’s a matter of appropriate compromise. Judging by market penetration, Dyno Innovations seems to be the latest local company to find the balance. 

As featured in Australasian Automotive April 2022.