September 2024 – Article by John Greeven, Instructor at Oregon State University College of Engineering. There is a white spot visible from space which is called the Great Salt Lake in the state of Utah in the American west. The nearest large city, aptly named Salt Lake City, is nearly 200km away. Remote it is, but people have been coming here from all over the world for about 75 years to be a part of an international spectacle called Speed Week, hosted by the Southern California Timing Association at the fabulous Bonneville Speedway.
Bonneville Salt Flats (red line) in the Great Salt Lake of the American west. Source for the satellite photo: earthobservatory.nasa.gov/images/91765/bonneville-salt-flats
It is a massive expanse of salt which makes for a perfect place to challenge the gods of speed with all manner of inventions, from lightning-fast electric vehicles, to internal combustion machines burning everything from gasoline and rocket fuels. Lots of people dream about going… a few make the trip and watch this unique event, and a few lucky souls… very few, get in line and set a world record. Here’s our story.
Speed Week is a 7-day marathon. In this high-altitude salt desert, temperature and air pressure vary widely across each day. Winds are unpredictable, and inconsistent. It is very difficult to prepare and tune your vehicle to maximize its performance for the specific conditions affecting each timed speed run.
“How much time does it take?”. “All of it!”
We spent the first 4 days methodically adjusting and tuning and increasing our speed. We spent the first 2 days shaking down the motorcycle while the team learned the routine of getting in line, working on the motorcycle, and making speed runs. Initially, we tested new aerodynamic designs and engine modifications. We collected enough data to support a multi-factor regression analysis. From there the team settled in for two days dedicated to fine tuning the overall package, including refining fuel mixtures and tire pressures.
On Day 5, we exceeded the 21-year-old record of 83.981 mph (135.154 kph) twice by averaging 86.204 mph (138.732 kph) on Mile 2 of the course, and 86.636 mph (139.427 kph) on Mile 3 of the course, to attain ‘qualified status’, the first step in breaking a record. Our motorcycle would be registered at an Impound location where only 4 hours of preparations can be made (and no significant modifications), then the bike is locked away until the next day.
On Day 6, we picked up our motorcycle at Impound early the next morning, and got in line to see if we could achieve enough speed that the average of that ‘confirmation’ run, and the previous day’s qualifying run, would be above the existing record. Easy, right? Maybe, but so much can go wrong…
The Starting Line.
The next morning gave us good conditions: no wind, and a nice cool temperature of 25 degrees Celsius with a relatively low-density altitude of 6300 ft (1920 meters). We repeated record-breaking speeds twice by averaging 84.323 mph (135.705 kph) on Mile 2, and 84.524 mph (136.028 kph) on Mile 3 of the course to repeat and confirm our record. So far so good.
The last step was a return to Impound and be thoroughly inspected to ensure compliance with all rules. We were nervous, of course, but confident since we had recently set a record at El Mirage and passed that Impound process. Still, one never knows. A thorough inspection of the engine proved successful, and now they were checking the overall geometry regulations… and something didn’t look right. The inspectors found that the tail of the motorcycle extended rearward by less than 2 centimers beyond the rear tire. We realized in that moment that an earlier change in gearing and chain length ended up moving the rear wheel forward. That caused the tail to protrude beyond the edge of the rear tire… a clear violation of the rules.
Devastation and Determination. The team was devastated; all our work had resulted in a record which clearly didn’t count as official. We stood there paralyzed in disbelief for a moment, then someone said, “Let’s get back in line and do it again!”
So, we did just that. It was now the penultimate day of the competition, and there was no time to waste. We would have to make another run during the hottest part of the day, when our motorcycle was noticeably slower. A suboptimal situation, but there was no choice.
After the disqualification, we installed a newly developed and shorter tail fairing that was redundantly safety-wired to ensure there was no way for it to shift forward accidentally. This wasn’t necessary, but it did a lot to calm the team’s nerves.
We made a run at about noon, and it was already moving past 32 degrees Celsius with a density altitude of about 2150 meters. Our speed in Mile 2 of the run fell just short of the standing record. But conditions farther down course were better, and in Mile 3 we exceeded the old record by averaging 84.608 mph (136.163 kph), to again attain ‘qualified’ status! We barely made it, and only in Mile 3 this time. So far so good. Back to Impound for another thorough inspection.
We prepared the motorcycle for the next day’s run and left it overnight at Impound. I’d love to say that we all slept well that night because we had earned it, but the gods of speed gave us lots to worry about. The next day was Day 7, the last day of the competition. And on top of this, the organizers announced it would be cut short to a half-day schedule. We would have one more run to confirm the record, and only our time in the Mile 3 segment would count. No pressure!
The Final Day. We were among the first ones to arrive at The Salt, and we made our way to Impound around 6 am. We weren’t taking any chances. We wanted to be the first to run, and take advantage of the coolest temperature of the day. And the wind forecast for the early part of the day was for a quartering tail wind. Our run yesterday was barely over the record, only exceeding it by a tiny 0.627 mph (1.009 kph)! We needed a good run to have the two runs average above the old record. Focus! Everyone had to focus on their roles. We were waiting at the front of the line, and were informed that we should start our engine. With a little spray ether, and an Olympic bobsled-style push from our team lead, Connor Heath, our machine fired up and we began the warm-up procedure.
Dawn at the Bonneville Salt Flats.
This would be lucky run #11. Just like all the others. We knew what to do. Focus! The official at the starting line pointed to me, and then down the course indicating it was time to do this! The Aprilia ran flawlessly up through the gears, hitting 6th gear and continuing to rev higher though Mile 2. I could tell from the tachometer that we were in “record territory” entering Mile 3… but would it hold? We needed an average speed above the record over the entire the third mile. Would it hold?
Connor Heath push starts for the record.
Victory and Validation. This last run gave us a flying third mile average speed of 85.709 mph, well above the record, with an average speed over the two critical runs of 85.158 mph (137.049 kph). We broke a 21-year-old record at the Bonneville Salt Flats! Wait, not so fast! We needed to pass the inspection at Impound again! Well, needless to say, the “final final” inspection went well, and our record was officially recorded.
“SCTA Speed Week at the Bonneville Salt Flats, Aug 2024 This is what is feels like to break a land speed record at the Bonneville Salt Flats! - class - MPS-F 50cc. - previous record, Aug 2003 - 83.981mph - NEW RECORD, Aug 2024 - 85.158mph - interdisciplinary team of engineers, business and liberal arts students. The event also recorded an official flying mile run of 86.636mph during the week of competition so we left some speed on the table. We'll be back to collect on this.”
If you read the story of our previous record on Wide Magazine ( wide.piaggiogroup.com/en/articles/racing/the-great-challenge-new-land-speed-record), you will know that these competitions are not easy and tend to be full of surprises and challenges. This rookie student-team rallied together and navigated all of these successfully. A great job and one which we will all remember for the rest of our days.
Please consider sponsoring this university student project and help us continue teaching these important life lessons. Even a small donation would be most helpful. Please contact us by email at: 50ccLSR@Gmail.com
