Those of you who read our blogs will know that, in WEC racing, we follow some of the most exciting and technically advanced racing cars in the world. Some say that they are at the pinnacle of motor sport and not that ‘other’ series that makes the headlines.
However, today we find ourselves in very different circumstances where technology precludes all but the manufacturers from producing topflight prototype race cars. In previous years, some of these topflight racers from the hammers and spanners era, were built in garages, not laboratories, and by looking under the bonnet you could understand what was going on.
It’s good to wander round the garages and in the pit lane to find cars from the era we grew up with, enjoying a disreputable retirement. On my wanderings, I came across the team of MacG Racing, which is primarily a father and son team, Richard and Jonny MacGregor, who formed their team in 2010. In the same way that small teams could challenge the big guns in the days of old, so too is it their dream to develop a credible, competitive 24-hour endurance race car. This is by no means a simple challenge, as we witnessed with the Nissan GT-R LM NISMO in 2015.
The team’s driver, Jonny, completed a Masters Degree in Automotive Engineering at Loughborough University where he also excelled in rugby and 400m running. He proved himself to be a fast and highly competitive driver in some early motor races driving a 2-litre Westfield, breaking the Class record at Croft on his first visit to the circuit. The seeds were sown, and gradually ambition grew until the father and son team decided on a plan to build a more advanced track car. As we will see, this project rapidly developed into an ambition to go endurance racing, rekindling the early ambitions to take on the mighty factory teams.
The project to build a GT car began in Richard’s home workshop in Yorkshire. No one builds a car from the ground up without drawing on technology and experiences learned from other projects, and here MacG Racing was no different. The base for the 2016 24-hour car is an Ultima GTR, a superb car developed for the road, with an enthusiastic world-wide following. Despite such a sound base, it quickly became apparent that turning a competent road car into a winning endurance race car was too big a project for Richard and Jonny alone, and a team was formed from Jonny’s fellow engineering students from Loughborough University. The enthusiasm, skill, ambition and hard work in their spare time, resulted in the completion of the car, a highly capable GT racer, with a ready-made pit crew.
Motorsport is about pushing design parameters and exploring the relationships and interactions between the many facets of the car. The approach taken by MacG Racing was a gradual one, just making incremental changes. But changes don’t always result in improvements, sometimes you have to step back in order to leap forward.
The first step to take a road car to a winning endurance racer was to increase downforce and improve mechanical grip. This is where the chase to find optimum performance begins. Increasing downforce (aero) and mechanical grip (big sticky tyres) was achieved relatively easily after lots of calculations and computer modelling. But this highlighted a problem in the drive train, or as the engineers like to phrase it, it was ‘operating outside of the design parameters.’
These findings required a redesign of the drive shafts and suspension uprights all of which overcame the initial issues, this work being done in-house and ultimately being made commercially available to fellow racers. At least that stopped the drive shafts snapping, but this just pushed the stresses further into the drive train, so the next stop was the gearbox. The Porsche G96-50 gearbox was not coping with the stresses put on it by the GM LS7 power unit and the new grippy tyres, and this introduced a new challenge, thermal load. Stripping down the Porsche gearbox, it quickly became apparent that the design envelope had been exceeded and there was no further development potential within the MacG Racing budget, so an alternative gearbox was sought.
Motorsport is truly a worldwide business, so when your German gearbox isn’t able to cope, you naturally look to Australia don’t you for an almost bomb-proof gearbox? Anyone who has watched the V8 supercar series will understand. Step forward the Albins ST6 gearbox, a 6-speed synchro gearbox which is tried tested, robust and easy to work on, and looks pretty amazing too.
When I started talking to Jonny about the initial problems faced by the road car on the track, he raised the issue of thermal load in addition to the myriad of mechanical issues discussed earlier. Pretty much everything that happens in a complex machine generates heat as a by-product, and unless heat is managed it can have a catastrophic effect on the car. The most dramatic of course is fire, but unmanaged, heat build-up can destroy vital components just as easily. Endurance cars run at full load for long periods of time pushing and forcing the design parameters of not only components, but also the layout of the components. Designing airflows to counter heat build-up can disturb aerodynamics, increase drag and result in higher power requirement which in turn leads to a greater thermal load, an infuriating vicious circle.
Heat build-up was in part responsible for the failure of the gearbox, not heat within the gearbox, but heat that caused fuel to boil which in turn caused the engine to misfire and send massive shocks into the gearbox. Heat in the cockpit caused the engine management system to fail and the car to stop out on track. Clearly heat management was becoming a huge issue, and one which had to be addressed on a holistic basis. Sure, there are individual work-arounds, but they are compromises and endurance racing actively seeks out compromise, and punishes you just when you least need or expect it.
Whilst running the car in this modified state, with uprated drive train, it become apparent that the chassis was being asked to perform outside of its design parameters. Looking ahead, this would seriously hamper the evolution of the MacG endurance racer, and so the time had come for a radical review of the challenges that had been overcome to date, the current obstacles, and some blue sky thinking to predict the likely problems. This would include the issue of not only building a fast reliable racer, but one that could be easily serviced in the middle of the night when the clock was ticking. The decision was taken to redesign the chassis, and with it the MacG Racing Taranis was conceived.
Taranis, Celtic God of Thunder and Lightning, Lord of the Wheel, it really sums up what endurance racing is all about. Sure, there are other series that limit noise levels, or where fuel is so tightly controlled that flaming exhausts are shunned. But the MacG Racing Taranis is really the epitome of endurance racing with the looks and style of the classic Group C cars, with lots of grunt, big wide tyres, and a huge grin factor for all concerned.
Jonny MacGregor is a very personable and modest young man who has an enormous amount of technical knowledge and experience. He is well thought of and respected by leading exponents in the industry. So when he decided to design a chassis for the Taranis, it was not taken lightly. Meticulous attention to detail, computer modelling and much testing resulted in a chassis stiff enough to deal with the stresses and loads of the modified drive train and improved aerodynamic performance. It also resulted in a significant weight saving. Something that surprised the highly respected, old-school chassis engineer who built the chassis to Jonny’s design. Not only does the chassis meet the brief for loading and weight, but it is also designed to allow component placement to assist with air flow to manage thermal load, allowing the best use of space, and making the servicing of components easier. It might not be rocket science but it’s pretty close.
No one will deny that MacG Racing is grass roots motorsport, but the level of professionalism they bring would not look out of place in the FIA WEC paddock. And so after many hours of planning, designing, building, testing, redesigning and assembly, we find ourselves at Donington Park on a Tuesday in February for the first roll out of the MacG Racing Taranis. The first step on a long road to the Barcelona 24-hour race in August.
Watch this space!
Words and images by John Mountney