IMSA: Series conducting off-season performance tests

IMSA: Series conducting off-season performance tests


IMSA: Series conducting off-season performance tests


With the 2014 TUDOR United SportsCar Championship completed, the series’ technical department has launched its first major off-season information gathering project. According to Scot Elkins, IMSA’s managing director of technical regulations, comprehensive testing with the cars that comprise the GT Daytona class is being performed with one goal in mind.

“We have one engine from each GTD manufacturer going on the dyno – those are the ones we pulled at Petit,” Elkins told RACER. “And then we have one chassis from each GTD manufacturer that’s going in the [wind] tunnel during the second week of November. It’s all a validation and data gathering test. We’re not trying to do performance balancing on the engines, because that’s not really how the GT3 spec works.

“We’re going in and giving ourselves a good idea of where everyone is and building a database on how certain restrictor sizes affect each engine. From there, we have the data and know if we change a restrictor by five millimeters, it impacts each engine by a verified amount.”

IMSA’s GTD engine testing follows the same procedure it used earlier in the year to map how restrictor changes affected DP and P2 engines. Charting GTD aerodynamic changes is being performed for the same purpose.

“We’re looking at the same kind of thing in the tunnel, and it gives us better data to make decisions on any changes to GTD aero next year,” Elkins added. “It also helps us improve the accuracy of our sim models. And this kind of testing really helps confirm the real influence of restrictor changes or wicker changes. We’ve seen a restrictor change might not make that much of a difference on one engine, but reducing revs does the trick, so it’s also a process of confirming which type of changes will produce the result we’re looking for. We’ll run different RPMs on the dyno, different restrictors, and build a deeper [Adjustment of Performance] table.”

With new P2 coupes coming into IMSA next year, Elkins also expects to spend some time evaluating the aerodynamic differences between the open-top cars that raced in Prototype and the latest offerings from HPD and Ligier.

“We’re going to take them to the wind tunnel and get a feel for their aero sensitivities and continue working from the baseline we had [for the Ligier] at COTA and Petit,” Elkins explained. “They are definitely improved in a lot of areas, so we’ll see where they are in terms of Le Mans trim for Daytona, which is the first race they’ll run, and we have a pretty good idea on restrictors with the HPD engine.

“And we’ve been in conversation with the folks at Judd to get that process started with Krohn’s Ligier. We’ll also be in the tunnel with the DP cars as we try to balance the new Corvette C7 bodywork. There’s plenty of work for everyone to do that will keep us busy during a short off-season.”