After a five-month absence, Starworks Motorsport’s Honda-powered Riley DP returns to action this weekend at Road America, following significant aero and cooling updates to the Prototype class car.
Cooling issues initially plagued the new-for-2014 package, which debuted at the Twelve Hours of Sebring in March.
It led to a complete redesign and rethink of the installation and aerodynamics, an initiative spearheaded by HPD and Riley Technologies.
“The only effort we had was patience,” team owner Peter Baron told Sportscar365. “HPD and Riley really took over over the whole project.
“About two weeks after Sebring, we brought the car up to Riley’s shop and worked with the series and came up with a few different options on the way to rectify the cooling issues.”
One of the options was the installation of a roof-mounted air duct, but Baron said it was ultimately not approved by the IMSA. They instead had to go back to the drawing board in June and relocate the cooling ducts to the pillars.
“They did a ton of high quality CFD design work and flow analysis,” Baron said. “It all came together with a plan that got approved in early July.
“Honda did a fantastic job just getting it all done. A lot of the parts were all rapid prototypes.”
The car, in its reconfigured form, turned its first laps in a two-day test at Road America last week.
Alex Popow and open-wheel ace Enrique Bernoldi handled driving duties of the DP, which didn’t miss a beat over the six hours of running time.
“We were naturally a bit skeptical whether it was going to work or not,” Baron said. “But it came out perfectly. Not one thing went wrong with it. There was not one teething issue.
“The car ran cool and was getting all of the boost it was supposed to get because the intercoolers were working properly. It was getting all of the right temperatures to the air box.”
It was then straight to NASCAR’s R&D Center, where the updated package was put through its paces in the wind tunnel for IMSA’s aero Balance of Performance validation, a test that went through the night on Monday and into the early morning hours of Tuesday.
With the aero configuration having been put together at the last-minute prior to its debut at Sebring, the wind tunnel test provided tweaks to the package, such as reshaping some of the dive planes.
“We went to the tunnel with the emphasis to get rid of the drag,” Baron explained. “If we lose some of the downforce in the process, that’s OK.
“I think right now, the way it looks on the tunnel, we’re a little bit low on downforce but we’re in the ballpark with drag. So hopefully, we should be doing pretty good here.”
In addition to the aero and cooling work, there’s also been updates to the 3.5-liter twin-turbo V6 powerplant, which has shed about 13 pounds since Sebring, as part of a car-wide weight reduction initiative.
Baron, meanwhile, is quietly optimistic of showing a good result in Sunday’s two-hour and 45-minute race.
Team veteran, and defending GRAND-AM race winner Scott Mayer is joined behind the wheel by Honda IndyCar star James Hinchcliffe, who makes his first DP start in more than eight years.
“We need to show that the car is back,” Baron said. “As a team we need to execute well and just make sure we run it properly and get the potential out of the car.
“I don’t want to say it’s a position-related finish [we’re after], it’s more an execution and getting the car running competitive and everybody gelling well.”
Baron hopes to complete the season with the Riley-Honda package, with Popow potentially jumping into the seat for the next round at Circuit of The Americas, ahead of a targeted two-car program in 2015.
“If it goes well, we’ll go to COTA,” Baron said. “But if we come out of here and see that we still need a little bit of work, then we’ll maybe skip COTA and focus on Road Atlanta.
“We definitely need to hit Petit Le Mans, for an endurance run. By Petit, a lot of the parts will have 20 hours on it, which will be a good reference for the 24-hour [in 2015].”