Part 5: IMSA: Where you win and officials screw you out of it.
If the Audi has a fuel cell capable of holding 100 liters, and IMSA decrees 91 liters as the R8's maximum for the event, teams like Land and Magnus would rely on a few popular choices to fill the cell with objects that take away the extra nine liters of capacity. Some use hard plastic balls, which displace a certain volume, and others use blocks that can be molded in different shapes.
Think of it like filling a 12-ounce glass with ice cubes. Without the cubes, the glass will hold all 12 ounces from a can of soda. Fill the glass with ice cubes, and you'd be lucky to get six ounces into the glass. The same principle applies here with inserting items into a fuel cell to comply with the maximum fuel allowed.
If, by chance, a team like Land used blocks that were positioned in specific, tested places in the cell, and had shapes that provided the least amount of turbulence – drag – when the fuel started flowing in from the refueling hose, the cell would reach its 91-liter maximum faster than the other cars.
It's a basic case of working with the R8's fuel cell to come up with the fastest way to 'pour' fuel into the car, akin to finding the perfect locations for those ice cubes to get the soda into the glass long before everyone else. Land's efforts produced refueling times said to be in the 35-second range, and with the team also placing a heavy emphasis on completing its tire changes faster than ever, time was shaved there as well.
The final component that led to the minimal time spent on pit lane during those early stops came from the byproduct of rocket-fast tire changes. With the team able to pull the air jack and drop the car sooner than most of its rivals, the Audi sat lower to the ground, which helped increase refueling speeds due to the use of gravity.
Combined, the Land team aced every phase of its pit stops, and it was plain for IMSA to see. So how did the team manage to comply with the 40-second/fuel rate expectations after the penalty? An easy solution was floated: The refueler would stay connected to the car for 40 seconds at each stop. THAT REQUEST, TO MY SURPRISE WAS DENIED!
To avoid running afoul of the fuel flow issue, the Land team would need to slow its refueling rate, and despite lacking real-time data to aid in this venture, the person controlling the refueling tank's shutoff valve – commonly referred to as the 'dead man' valve – had to change the practice of pulling the lever to open maximum flow into the hose, to partially closing the valve – throttling down the flow rate manually. It was an imprecise method, but it worked. No further penalties were given.
Although the Audi and all of IMSA's homologated cars have schematics that detail aspects of how the fuel cell must be assembled, IMSA's rulebook for the GTD class does not provide instructions on where those balls or blocks must be placed. It is, as Land found, open for interpretation and exploitation.
Reportedly, the Magnus Audi team did not make the same efforts as Land to optimize its fuel cell, and took somewhere between two and three seconds longer per stop to fill the No. 44 R8. It points to one team within the German brand's IMSA customer base finding an open area to maximize.
Per Rule 9.13.3, the GTD rules say "Entrants may use blocks or balls to achieve maximum fuel cell capacity." The only written warning covers efforts to cheat the IMSA-mandated fuel capacity set for each race: "Any device, system, or procedure designed to increase, even temporarily, the total fuel storage capacity beyond the maximum is prohibited."
And that's where the story comes to an end.
NEXT STEPS
The cell was LEGAL, the tank and restrictor were LEGAL, and through some nebulous wording, Land's crafty work was TURNED FROM A NEARLY TWO-LAP LEAD TO A DEFICIT OF TWO LAPS or more in an instant. If only hard rules existed to facilitate the penalty that was given.
Moving forward, I would not be surprised if the BoP tables for the next round at Sebring, and all rounds afterwards, carry written refueling time targets for teams to use as official rulebook compliance items.
I would also expect a highly definitive fuel cell configuration document to be produced by IMSA or Audi to make sure a Land-style flow advantage becomes impossible to achieve after Daytona.
What's the lesson here? DOING TOO GOOD OF A JOB – even when the series agrees it was 100 percent legal – isn't acceptable within the constructs of a championship that relies on BoP.
Last edited by senor honda; 02-06-2018 at 08:16 PM.