Given the same problem to tackle, different engineers will come up with different solutions. Now most of those solutions will work, they will be valid, and could happily be applied. There will always be a few that are just a little too “out there” to make it.
The interesting thing with solutions is that the best one can vary wildly depending on the circumstances. What works during a design stage, or during testing, is not necessarily going to be desirable during a race situation. An example from a recent race… On a British Touring Car there is a small radio receiver known as the “Beacon”. This clever little bit of kit is used by the on-board electronics and data logging systems to separate each lap during a race. It provides a cut-off between laps, and generates the comparative lap time and split timings to the driver on the dash display. In all honesty, this is not a critical piece of kit for the race. The driver rarely looks at his laptimes during a race. It’s main use is during post-race analysis where data engineers such as myself can use it for comparison and navigation. Where this is important the driver however, is during qualifying. During qualifying, a driver wants to know exactly where he or she is gaining or loosing time, and would like a comparison to a previous or theoretical best lap. Not having a beacon during qualifying is a huge disadvantage. During a recent BTCC round, we noticed that the driver radioed to say he did not have laptimes appearing on the dash. When the car came in for new tyres, I inspected the beacon and saw that it’s mount had rotated around the rollcage meaning it no longer pointed out of the window. No line of site to the transmitter means no lap time. A simple fix; I forced the beacon back around and away he went. Three laps later, we receive another radio call. "No Lap Time." Damn. However, this time I was ready. Before the car was back in the pitlane, I had several lengths of duct tape torn off and taped to my trouser (USA: Pant) leg. As soon as the car stopped, I rotated the beacon again, and secured it with copious amounts of tape. It was crude and messy. It was not what you might call the ideal solution. But the two most important things about this particular solution are:
Would duct tape have been approved when the car was designed? Of course not! Would it have been signed off during the build process? Nope. Had the issue occurred during testing, would the duct tape still be on the car? I really doubt it. My duct tape only stayed on the car for qualifying. Before the race, I applied a much neater and permanent solution. Rubber strips installed between the rollcage and mount mean nothing moves now. This was also applied to the second car in the team to proactively prevent the issue happening there too. Solutions can be fluid, they evolve and develop. Solutions should not only match problems; they need to match circumstance. As an engineer at a race track, you need to be prepared to come up with fast but workable solutions. You will be under pressure. No one will expect your solution to look like art work, but they will certainly expect your solution to work.
Did you enjoy this article?
0 Comments
I finished university several years ago full of enthusiasm and confidence. My degree was strong, my knowledge base solid and my vision of the future crystal clear. However, my first assignment in my new job role opened my eyes to just how little I really knew about the motorsport world.
Having worked for Cosworth Electronics for a matter of weeks, I was sent to support a World Record Attempt for a twin jet turbine engined speed boat. Not the formula cars I had worked on throughout university. Not the closed wheel monsters I was familiar with from weekend work. Speedboats. Now don't get me wrong, speedboats are cool. This particular speed boat had over 6000hp and was over 15 meters in length. Despite its carbon fibre hull, the catamaran still weighed 3 tonnes. This thing was a colossus. The boat was so far removed from anything I had learnt about during my studies, and was not something I had even considered when it came to motorsport. Suddenly, I felt way in over my head. I spent the 2 days prior to the run getting familiar with the beast. I traced wiring through the hull. I plugged in my laptop and offloaded datasets, settings and logged data. I scrutinised every aspect of the boat that was accessible to me in an attempt to understand the task that lay ahead of me. I kept in constant contact with more experienced engineers back in the UK, and slowly managed to take a bite out of the huge elephant. I was fortunate that support from Cosworth was fantastic which really helped things. Then came the big day. A world record attempt was on the cards. A fear of overshooting the stopping zone at the end of the course meant dragster style parachutes were attached to the boat. Unfortunately these deployed prematurely due to the intense g-forces. On that failed run, the boat made 210mph. TWO HUNDRED AND TEN MILES PER HOUR WITH THE PARACHUTES DEPLOYED. This indicated that the parachutes in fact would have very little affect, and so were removed for run number two. Despite a nasty accident of another boat during the event, the pilots throttled on from the staging area and brought the speed up. All the way to 244mph. A new record. My part in this endeavour was small. The boat had been set up prior to me arriving by a colleague and I was really only there to monitor for errors. But I was still a part of it. The feeling within the team, with the pilots, the engineers, the mechanics, was euphoric. I had survived my baptism of fire. And am a far better engineer for doing so. Carroll Smith felt strongly that every apprentice, every mechanic and every engineer that worked on a race car should have attended a driving school prior to doing so. The reason he thought this was a good idea (and even included in his own apprenticeship programs) is it is the best way to gain an understanding of how a car behaves. Learning about understeer or oversteer or balance or aero effects from a text book doesn't mean you know what understeer, oversteer, balance or aero effects actually are. You cannot have a kinaesthetic feeling for what they actually do to a car.
Gaining experience in how a car behaves will set an engineer apart, especially early in his or her career. Drivers, for all the skills, are not necessarily engineers. I have worked with numerous drivers over the years and there are some who strive to have a thorough understanding of the car and the laws of physics, and then there are those who drive on feel and can struggle to communicate what the car is doing, or even what they want it to be doing. If you, as their engineer, can decipher what it is that they want and need from the car, then you are going to earn your pay at the track. If you can understand elaborate hand motions and wishy-washy language from a driver who is not an engineer, you are doing very well. Understanding how a car really behaves, in the real-world, transient conditions found on a race track does not come from university lectures, college classes or 2 inch thick text books. It comes from experience. It comes from taking the time to throw yourself in to the experience of racing. In all likelihood, no one will pay for you to learn to drive fast. You'll have to fund it yourself. Although as your experience and network grows, you're more likely to find someone who can help you make it happen a little cheaper. If you get the chance to start translating what a driver is telling you in to a real world take it. It will be incredibly valuable to you as an engineer, and it will probably be a lot of fun… Everything on a racing car affects something else. Nothing works in isolation, and understanding the complex systems and links between the systems is crucial to engineering a winning car.
I've discussed before how compromise is needed to win races. That having an optimal overall system is more important and optimising each system on its own. But within those systems, you have often unseen and not so obvious links that can have a detrimental effect on the overall package. I'll use a few examples to show you what I mean: Engine Mapping Most modern racing cars will have the ability to alter the engine map depending on driver preference and prevailing track conditions. This usually involves altering ever so slightly how power is delivered, however some championships may allow for more than this. There are situations where more aggressive, higher power engine maps are used during qualifying for example. These maps put a huge strain on the engine, but are only used for a relatively short period of time. What is often overlooked is how these engine changes will affect the traction. A driver may complain that they cannot use the power when they want to out of corner, and so a less aggressive map will be used. However this will reduce the slip ratio for the driven axle, potentially inducing understeer. Worse than this, your chassis engineer may decide that the issue of corner exit traction can be rectified through kinematic and geometry changes. If both chassis and engine changes are made, you can easily end up going too far and ruining the overall balance or making the car sluggish. Ride Height Changing ride heights is one of the fundamentals of setting up a race car. It will have a direct effect on the roll center of the car, and as such a dramatic effect on the handling. It is something that is usually something that can be changed quickly, and often by only a few millimeters (See Small Changes). However the ride height does not act in isolation. Changing ride heights will have an effect on the suspension kinematics; the way the wheel is controlled and moves under bounce and rebound. If this is not taken in to consideration when the ride height change is made, the results can be unexpected. Now most race cars will have adjustable everything on each wheel - camber, caster, toe, K, etc. - but if they are not changed in a systematic and controlled way, you can spoil the balance and handling of your car. Another often overlooked effect of ride height changes is the affect it can have on the aerodynamics of the car. A car running a little too high or a little too low can be comes unstable and even dangerous. Adjustable splitters, diffusers and wings are there to accommodate changes where necessary but there is often a limit to what can be done. Tyre Pressure Changes Yes, even the simplest of changes to make can have knock on effects to other areas of the car. The tyres can be thought of as a spring, and they do play a crucial role in the spring rate of a wheel system as a whole. The entire system (from contact patch to chassis mount) has a spring rate that is known as the "Wheel Rate". Changing the tyre pressure will change this value. To a degree, tyre pressure changes can be tolerated by the suspension system. Plus or minus a few tenths of a bar won't have dire consequences. But if you start playing around with larger pressure changes, you will fall in to a trap of chasing ghost springs in your system. I have also seen cases where tyres were calibrated using nitrogen, but run using compressed air. The difference in Gas Constant meant the tyres were completely out of kilter with where they were expected to be. They came back from a run massively overheated and over inflated. Before committing to a change on a car, think carefully about where the change will have an effect. What other systems might be altered by your change? How can the changes be negated or accommodated? Compromise wins races. But knowledge definitely helps. What is the resolution for a change in ride height? 0.1mm How much will an engine tuner change their target lambda by? 0.01 Camber and toe changes tend to fall in what range? -5° to +5° And what increments do we change them in? 0.1° What is the operating range for engine temperatures? 80°C to 85°C How much do we alter the angle of attack of the rear wing? 2-3° What is the tolerance on a go/no-go gauge? 0.01mm Tire pressures - what do they get adjusted by? 0.05bar What is the accepted error on ignition angle? 0.001° How much extra fuel do you carry? 5% Ballast can be moved in what size increments? 0.1kg How much over the boost limit will get you disqualified? 0.01bar How much can you win or lose a race by? 0.001sec Don't think a change is too small, that it is insignificant. That change is what makes you win. It is the accumulation of tiny changes, of the slightest improvements, that make the difference between first place and everyone else. Being prepared to make adjustments on the micro scale will show itself in the results on the macro scale. It separates those who win from those who compete. And you only show up at the track to win. Never to just compete. You won’t always win. That is the nature of motorsport. Everyone wants to win and everyone strives to win, but only one team can win.
If you turn up to a motorsport event without believing you can win, then you have already lost. Henry Ford once said “Whether you believe you can or you believe you can’t, you are right”, and nowhere is that more true than in the competitive arena of motorsport. Being confident in your ability as a person and as a team is a big part of achieving that podium top step, but the danger is that confidence gives way to cockiness, which in turn breeds complacency. At this point, you have lost. During the early 2000’s, Formula 1 was dominated by Ferrari and Michael Schumacher. The combination of blistering performance from the car, and the unmatchable talent of the driver meant the races became “who’s coming in second place today?” contests. Following that, Renault dominated with Alonso. Then it was Red Bull with Vettel. And now it is Mercedes. Do you believe that these teams ever become complacent? Do you think they are ever overly confident in their victories? No. These teams, the engineers, the mechanics and the drivers, put the same effort in whether it is they are chasing their first win of the season, or the tenth. The work is relentless and even after a championship is secured, they push until the chequered flag of the final race. Everyone in these teams believe they can win. All that being said, sometimes things don’t work in your favour. Bad weather, a puncture, an accident; things will work against you and the victory will seep away. Sometimes you will enter a championship with a car that is simply not competitive. When Mercedes turned up at the first race in 2014 with their wildly out-of-the-box-thinking split turbo V6, they dominated. No one else was competitive. But they all still turned up and they all still raced. At Canada, something happened. What Mercedes would call a disaster, and what Red Bull would call a miracle. The two Mercedes cars suffered almost simultaneous failures of the Kinetic Energy Recovery Systems (MGU-K). The result was the 20 second lead was worthless and Red Bull claimed the first non-Mercedes win of the season. Red Bull had ploughed through and it had paid off! So no, you will not always win. You will not always make the podium. You will not always be competitive. You will not always even finish the race! But if you give your everything, to every race, eventually you will win. Stick it out. |
AuthorTom is an engineer working his way through the motorsport industry, sharing stories, anecdotes and lessons to help new engineers coming through the ranks. Archives
June 2017
Categories
All
|