IMSA: Revisions to HPD ARX-04b impress Shank

IMSA entrant Michael Shank Racing and Honda tested the HPD ARX-04b prototype on Thursday at Sebring after the issue-plagued prototype sat for more than a year awaiting improvements. The early prognosis was very positive, according to the team's owner. (Watch video footage from the test at the end of this article.)

"We got a lot done and the car is significantly better," Shank told RACER. "And remember we were here [at Sebring] just two weeks ago for the 12 Hours, so we got a good feel for the car in good conditions like we had before all the rain in the race. It's a lot closer than it was last year and the gains they came up with were pretty significant. A lot of people worked really hard to get it where it is."

The chassis, which was designed and manufactured by Honda Performance Development and partner Wirth Research, was overweight and produced insufficient front downforce during its brief competition debut with the Tequila Patron ESM team at Daytona in 2015 (RIGHT). Efforts to fix the aero issues in a follow-up test at Sebring were unsuccessful, which led ESM to return its ARX-04bs and revert to the previous model, the ARX-03b.

Behind the scenes, HPD placed the ARX-04b on an intensive weight-saving program, and modified some of its aerodynamics, including the fitment of ARX-03b sidepods. Building from its strengthened relationship with MSR, which fields the only full-season Honda-powered entry in IMSA's WeatherTech SportsCar Championship, HPD tasked the Ohio-based team with returning to Sebring to put the updated ARX-04b through the paces. MSR veteran Ozz Negri handled driving duties.

"They got the weight way down," Shank continued. "It's right where it is supposed to be. We have plenty of room to move the weight around to put it where we want. The aero balance is much better. It's not very far off our Ligier. I can't go into lap times, but I can say we were pleased. We had no expectations with the car going in, and Sebring is a tough track to make a car work, so when you can, you're doing something. It's all positives that we're taking out of here, and we just ran it and ran it and had no issues. Everyone at Honda was happy, Ozz was happy, and that's no B.S."

MSR will await instructions from Honda on next steps with the ARX-04b.

"We don't have any plans for it yet, but it will be at our shop and ready to go for whatever might come with it," he said.

Up next for IMSA: Shank's Ligier JS P2-Honda and 24 additional WeatherTech Championship cars will head to Long Beach for Round 3, the 100-minute BUBBA burger Sports Car Grand Prix, on April 16.