Innholdsfortegnelse for January 2021 i Racecar Engineering

The trucks are now back at base and the racecars won’t run in anger again in 2020. Returning home to England feels great after what can only be described as a really odd season of racing in the US. When the IMSA season restarted after the spring lockdown, the schedule had to be compressed into a much shorter period. What this meant for the teams is nobody had a day off for a long time as it was a case of prepare the cars, travel, race the cars, travel, repeat. We returned to competition in July, had all of August off, and then finished the season in another two and a half months, so we had a total of just three and a half months of racing (the IMSA season…

Cliff Daniels was, until recently, crew chief on the no.48 car of Jimmie Johnson for Hendrick Motorsport and, for 2021, will run Kyle Larson in no.5. He is well accustomed to working with the Pit Rho system and made the following observations on how it has changed his role. ‘The cool part is you’re able to take a 10,000ft view and say, ‘Okay, I know x based on empirical data that I’ve experienced, decisions I’ve made, outcomes I’ve seen based on a certain race or race strategy. When you then pair that with a machine that is literally crunching numbers in the moment, to the millisecond, based on all the different environmental variables and factors – speed, fall off, pace, competitive strategy, predicted competitor strategy – all these different aspects.…

‘The damper is the brake of the spring.’ In this article we will review that theory, as well as the pros and cons of some oversimplified quarter-car simulation. If you would put a mass on a spring with no damper and push the mass down by 60mm (as seen on the green trace in Figure 1), then release your force, the mass will oscillate indefinitely. We should say nearly indefinitely because ultimately the movement will stop, mainly due to the spring material internal resistance, but also because of air friction. Note that in this example you allow the spring to work in tension and move not only down but also up by 60mm. As we will see later that is not the case in most car suspension. The mass position,…

The revelation that a limited edition ‘reproduction’ 1958 Vanwall VW5 F1 car is being created by Hall & Hall has been followed by a similar announcement concerning BRM’s fabled 1950’s Type 15. Jaguar had already pre-empted the dash to cash with its ‘continuation’ of the Le Mans-winning D-Type sports racer, preceded by XKSS and lightweight E-Type reproductions. There will undoubtedly be more such examples, as current technology means there is virtually no limit now to what can be viably reproduced, given people with deep enough pockets to buy them, of course. Purists have no doubt thrown up their hands in horror, especially those fortunate enough to own the pur sang racers. What effect will there be on the stratospheric values of their prized investments now that just rich – rather…

With the introduction of Technical Directive 37, multiple engine modes for qualifying and races were banned, and with it went Mercedes’ Strat 2, or so-called ‘party mode’. As qualifying is for outright pace over a single lap, considerations for the deployment strategy beyond the start / finish line go out of the proverbial window. In qualifying mode scenarios, teams would essentially leave the pits with a fully charged battery and end the hot lap with the battery completely depleted, with little consideration given to the laps that follow. There is also a damage function in such a mode that protects the power unit if exploited for more than a single lap without time to recover energy and cool the electrical systems. We have not suffered specifically because of Technical Directive…

Q We race off-road trucks that have upwards of 10 inches of wheel travel. We have trouble getting adequate rate out of our anti-roll bars and still having them last. If we make them thin and soft they’ll last, but they don’t do much. If we make them fatter, they get stressed past the yield point and either break or take a permanent twist. Is there anything we can do to improve this situation? One idea that has been suggested is to have the drop link act near the middle of a trailing arm. Would that help? THE CONSULTANT A There are ways to reduce stress levels in either an anti-roll bar or a torsion bar that holds the vehicle up, but what you can actually do on an existing…

One of the most important, yet most often forgotten, set-up items in engineering a racecar is the differential. The reason it is so important is it plays a critical role in both power delivery and car handling. Ignore both at your peril. A couple of years ago I addressed this matter at length, but recently received a great question on what your ballpark differential wheel speeds should be. That offered a perfect opportunity to re-visit this important chassis engineering topic. The principal problem we have with the differential is we have two wheels moving at different speeds, as illustrated in Figure 1. The reason tuning the differential is such a mess is that for a given forward speed, V, and a given yaw rate, r, because the wheels are separated…

Travel from Milan to Modena, both famous for their contributions to automotive history, and roughly midway along the two-hour journey the E45 bypasses Parma. Head due west along rural roads for 40 minutes and the sand-coloured Castello di Varano De’ Melegari signifies your arrival in the small village (population 2500) of the same name. Renowned for its imposing 10th century castle, Varano De’ Melegari is better known in motorsport circles as home to the world’s largest producer of racecars, Dallara, founded by the region’s most famous engineer, Gian Paolo Dallara, born locally in 1936. In 1959, Dallara graduated in aeronautical engineering at the Milano Politecnico University, then immediately joined Ferrari and worked his way through various technical departments, before moving to Maserati to join its sportscar racing operation full time.…

Q I wonder, if you have a Watt link instead of a four link to handle acceleration forces, do you calculate anti-squat in the same manner as with a four link? Oh, I forgot one important piece of information. The vertical link is not welded to the axle, it is linked at its centre as a normal Watt link for conventional lateral forces. Let’s say it is mounted on the rear upright, the differential is mounted on the car itself, we have live driveshafts with CV joints and the rotating of the upright is handled by one lower arm, which will not twist. THE CONSULTANT A Is this an independent suspension, then? You are considering a lower arm that cannot twist, as in an E-Type Jaguar, but allows fore and…

Hearing the news that a car has passed its crash test is now commonplace in racing circles. As advances in computer software through the design phase improves, so does the ability to predict how one will deform, but it was not always the case. Racecars from all series have often failed their first impact tests before heading to the track, particularly as rules tightened at key moments and design teams had to react quickly, perhaps with the risk of losing performance. Long gone are the days when crash testing meant dropping a car, or component, from a crane into the ground to estimate the likelihood of a driver surviving the impact. Also behind us are the days when racecars would not even be tested, extra material only being added in…

One bumper weekend in November saw the conclusion of the fight for Formula 1’s drivers’ title, IMSA, the GT World Challenge Europe and the FIA World Endurance Championship. It wasn’t that long ago that NASCAR, IndyCar and the Australian V8 series all declared their champions either. In a truncated season, such as 2020 has been, it was inevitable the series should all come to a grinding conclusion at a similar time. But what the teams, suppliers, manufacturers and organisations have achieved to bring the season this far in such circumstances, not to mention the print, digital and television media, is little short of extraordinary. At the start of the pandemic, companies rose to the medical challenge and helped to deliver a staggering number of breathing apparatus designed to help those…