Cooling Becomes The Hot Topic In Daytona
By Jonathan Ingram | Senior Writer
Daytona Beach, Fla. – As the temperatures climbed this week at Daytona International Speedway and the NASCAR Sprint Cup rulebook was altered almost daily, the hottest word around the garage prior to the Daytona 500 was cooling. In the new Daytona era of two-car packs, keeping the engine of the trailing “pusher” car properly cooled will be critical to the outcome.
As a result of the daily rule changes, it was like old times in the Cup garage between practices. Innovative solutions built by hand were being crafted and installed to the noses of cars in the space behind the air inlets and in front of the radiators. After NASCAR shrunk the inlet openings by 50 percent after the Budweiser Shootout, trying to improve the efficiency of the cooling was the goal of all teams.
“NASCAR makes a rule and then we figure out how to get around it,” said Howard Comstock of Dodge Motorsports Engineering.
“Teams will keep coming up with new cooling iterations right up until the race,” said Steve Hallam, the competition director for Michael Waltrip Racing, one of the Toyota teams.
Aerodynamics have always been important at Daytona. This year, if teams can get their drivers hooked up in a two-car tandem for an extended number of laps, the gains of 10 miles per hour can be sustained for longer periods of time. But only if the pushing car has good cooling efficency.
In the 300-mile Nationwide Series race on Saturday, the importance of cooling was clear. The tandem of Clint Bowyer and Dale Earnhardt Jr. was in position to win after working together for the final six
laps of green without swapping positions, which takes place to allow the trailing car to cool its engine. Bowyer lost only because Earnhardt Jr. elected to make a passing attempt approaching the checkered flag, allowing Tony Stewart, in tandem with Landon Cassill, to catch Bowyer by seven thousandths of a second.
The Cup teams were still working on trying to find better cooling as late as Saturday. But unlike the old days of squint and figure, the modern era of engineering has come into play. Teams have been running wind tunnel tests and using computer simulation to decide the best way to keep their cars cool.
“There’s probably wind tunnels all over the South that are still doing tests,” said Comstock on Friday. “We don’t have satellite link-ups, but we’ve got cell phones. Aerodynamicists are wide open. They’re going to try everything they can until Sunday morning to come up with what they think would be most efficient. We’ll probably draw a line sometime on Saturday when we’ll stop making any changes.”
Among the wind tunnels likely being used this past week are Aerodyn, Windshear and the Penske Technology Group facilities in Mooresville, N.C. and the Lockheed Martin tunnel in Marietta, Ga.
“There are some nuances, from manufacturer to manufacturer and within the teams from team to team on how to manage the air flow,” said Comstock. “Now that the smaller opening is the rule, there are some manufacturers that might have to adjust where they put that opening in order to be more efficient with their particular design.”
Comstock believes everybody is on equal footing when it comes to innovations. “We are all using the same lower (bumper). It should be fair between the four brands that the ductwork (between the grill opening and radiator) becomes a very tune specific tool that they use to get the most efficiency out of the front of their cars.”
Ford has touted its new FR9 engine as more efficient, which could be a significant advantage in Sunday’s 500-mile race. “We’ve designed it to run hotter and have less grill opening,” said Doug
Yates, chief engine builder of Roush Yates Engines. Yates said he has worked with all the Ford teams from the beginning to include the radiator installation and header tank used to maintain water pressure as part of a system to help the FR9 run cooler.
Originally, the idea with the FR9 was to cover up some of the standard grill opening with tape, to help create more aerodynamic downforce. But after the new two-car packs upped the speed ante on Daytona’s new pavement, the Fords might have an advantage if two Fusions hook up – especially at the end of the race scheduled for 200 laps.
A Chevy driver (Jeff Burton) and a Dodge driver (Kurt Busch) have been the winners in the Shootout and Duel events. Comstock believes the cooling of the Dodge R6 engine introduced gradually in the previous two seasons has something to do with Busch’s two victories.
“Cooling is one of the performance issues we could capitalize on when we built the R6,” he said. “I don’t exactly know how (the Ford) cooling system works compared to ours. It certainly was one of the design things we thought was important.”
Chevy’s R07, introduced early in 2007, appears to have efficient cooling as well and can run at the upper end of the heat range of 280 degrees. But Toyota’s NASCAR V-8, introduced in the same year, may be at a disadvantage, because its maximum operating temperature is closer to 240 degrees.
In the Nationwide race on Saturday, Kyle Busch and Logano had to swap more often than the Chevy or Dodge-powered tandems at the front. Once Carl Edwards suffered an alternator issue, Ford lacked representation among the leaders.
Not only is it a matter of engines or the metal ductwork behind the grill openings leading to the radiators. The placement of what’s now referred to as the “mail slot” opening in the nose is a critical choice.
The Fords have the openings at the very bottom of the nose, encroaching slightly on the splitter. In a
sharp contrast, Chevy teams tend to have higher locations for the opening. “We found a position that wasn’t at the bottom that was most advantageous,” said Mark McCardle, the vice president of competition for the Furniture Row Racing Chevy. Regan Smith, driver for Furniture Row, finished second after pushing winner Busch in the first Duel, when the smaller grill opening were used for the first time.
McCardle confirmed that all teams using the engines built by Earnhardt Childress Racing Engines had the benefit of wind tunnel testing conducted Monday evening – after NASCAR announced the reduction of the grill opening to 2.5 inches high by 20 inches wide on Monday morning, down from 5 inches tall previously. On Saturday, it was announced teams could increase the opening to 3 inches high out of concern about rising ambient temperatures at the Florida track.
By reducing the number of consecutive laps the trailing pusher car can stay in place due to cooling concerns, NASCAR officials hope to reduce the average lap speeds, which tend to escalate the longer tandems stay in place. After initially disallowing teams from running extra cooling hoses to the radiators, NASCAR reduced the grill opening and required all teams to run a Pressure Relief Valve of 35 pounds per square inch following the Budweiser Shootout. Less water pressure lowers the boiling point of the water in the engine, forcing teams to be more careful in the two-car tandems. If water boils out, it sharply reduces the cooling capacity.
The drivers are the wild card in the tandem when it comes to cooling as well as the crossover swap, or the trading of places by drivers due to cooling concerns. In the tandem formation, the air to the nose inlets is blocked, so breathing the engine is crucial. “Obviously it’s in the drivers’ hands,” said Yates. “They’ve got to watch the gauges closer than ever. It’s up to the (trailing) driver to get air to the nose.”
Ford driver Matt Kenseth pushed Chevy Kevin Harvick for a significant portion of the first Duel race. Kenseth said it was a short race and that he didn’t really watch his water temperature and pressure gauges while circulating much of the 150-mile race behind Kevin Harvick. “I wasn’t too careful whether it got overheated or not,” he said. But Kenseth may not have wanted to divulge just how he managed to keep his engine within acceptable operating temperatures. One of his tactics was to drift back several yards and then hook up again.
“Getting out to the driver’s right, getting a little bit of air to it, if the drivers find the right pattern of
doing that in a lap they’re able to keep the car at a reasonable operating temperature for quite a sustained period of time,” said McCardle.
“There is no air when you suck up behind somebody else bumper to bumper,” he continued, “unless you get out in the airstream to the right or go ahead and cause a separation of five feet between the cars for a short period of time and then hook back up.”
Yates confirmed the driver may be the key to success in sustaining long periods of two-car packs and allowing the engines to live. “The best drivers, the ones that figure it out the quickest are going to excel and the other guys are going to have to play catch up,” he said. “I think you could see Kevin and Matt really did a nice job and Greg Biffle and Carl Edwards did a nice job (in the Duels). Hopefully those guys will do the same on Sunday.”
McCardle’s driver Smith pushed Busch for as many as seven consecutive laps during the middle stretches of their 60-lap qualifying event on Thursday. The key to winning the Daytona 500 may be who can sustain a two-car tandem longer and find an edge in speed in the closing laps just as Bowyer and Earnhardt Jr. tried to do on Saturday.
Even if there are late cautions that reduce the race to a short sprint, a driver who blows up his engine won’t make it to the finish. Yates acknowledges that’s a concern at Daytona for the first time in years, because engines with the restrictor plates used at Daytona have rarely blown up due to less horsepower. In addition to running hot, engines can reach 9,200 RPM or higher in a faster tandem, which makes engine builders anxious.
“As an engine builder you live a little on the nervous side anyway and expect the unexpected,” said Yates. “I’m anxious to get into the race and get through the race and then go from there. But I like what I see so far.”
– Jonathan Ingram can be reached at email@example.comOne Comment