This is quite a weekend for racing. In Indianapolis, drivers qualify for next Sunday’s 500s. The WEC watched this morning’s action at a very wet Spa. Formula 1 runs at Catalunya in Spain, her favorite test track. And NASCAR’s Cup series is trying something new.
It should spend this weekend at Watkins Glen, in upstate New York. But 2020 did its thing, and so the picturesque circuit in the Finger Lakes, once the American home to Formula 1, is out of bounds. That NASCAR will race at Daytona for the second time this year. And for this visit, stock cars will use a layout that is more familiar to fans of the annual Rolex 24 sports car endurance race instead of the 2.5-mile (4 km) tri-oval.
Well, hurry. The 750hp (560kW) stock cars used in NASCAR’s cup series are a lot more powerful and have a much lower drag than the 180mph (290km / h) prototypes and the GT cars that race in the Rolex 24. Which would mean approaching 1 to 30 mph (48k / h) faster than those sports cars. And at 3,450 kg (1,564 kg) they have significantly more mass that needs to be regulated.
“When they started their entrance in turn 1, they would go 210mph [338km/h] and after 50 had to slow down to make the corner, and quickly we came to the realization that this would probably just not happen here for 65 laps, “explained John Probst, senior vice president of racing innovation at NASCAR.
From there, drivers will find an extra pair of corners in the form of a chicane shortly before the start-finish line, and the layout will be slightly expanded to 5.61 miles (5.81 miles). Making a chicane with speed bumps is not as simple as just putting out a few cones over what is normally the ski trail of the highway. Probst’s team turned to simulators to make sure that the profile of what is now running 13 and 14 would work properly.
“We tried to adjust it so that the cars entered at about 180 km / h [290km/h], “Probst told me.” And then we wanted to keep the car somewhere at 70 km / h [113km/h] in the middle of it. That, we configure the geometry of the chicane to get the midcorner speed up to about 70. “
However, this new harassment now means a round of the Daytona Highway now includes three major braking events – turn 1, the bus stop harassment (turns 9 and 10), and now this new final harassment. And so, expect brake control to be the order of the day in Sunday’s race 235-mile (378 km). For road surfaces, Cup Series stock cars use 12.7-inch cast-iron rotors with six-piston calipers at the front. You might expect the big challenge to prevent the brakes from getting too hot, but in fact, teams may have the opposite problem.
“One of the unique features here is that we’ll get really high speeds,” Probst explained. “That means a lot of airflow to the brakes. That the brute force approach of ‘more air is better to cool brakes’ would probably work if it was all turns and turns and brakes.” But between the 14 bends of the roadway are three long stretches of high-speed running.
Do not allow the rotors to cool down
“We’re going to have three very important braking events that will get a lot of temperature in the brakes, of course,” Probst explained. “But then you come from turn 6 – where the turn is back to oval turn 1 – and you go all the way to the bus stop flat-out. If we look at the speeds here, we would see them in the 190s. right now expect with the high downforce package, and that means they will cool down a ton by the time they get down at the bus stop.They will not be cold in the sense of frigid cold, but cold in the sense of remrotors compared to where they were at corner entrance, and they’ll do that round a few times, leading to cracks with the rotors. “
That probably won’t mean any remrotors. “If you have failed, it’s unusual for the cracks to be at the level where something is actually falling apart,” Probst told me, but repeated very cold cycles could well lead to problems for the drivers. “But what’s bad is when they’s glowing red red and then really cool and then rolling glowing then really cool – eventually they get to the point where you have geometric changes in the rotor itself, typically in the areas where the flushers would hook and stuff like that, ”he said. And unlike an endurance car in a 24-hour race, there is no provision for fast braking on a stock car.
The upside for fans in all of this is that longer brake zones create more chances for overtaking. How much longer? Before hitting the bus stop, Probst told me that NASCAR, disappearing on the conservative side, had issued four additional distance markers this weekend.
