Cadillac Racing will head into this weekend’s Pirelli World Challenge round at Road America with some extra horsepower, following the latest round of Balance of Performance adjustments from the SRO and PWC.

The Cadillac ATS.V-R has returned to similar boost levels the car had prior to last month’s round at Canadian Tire Motorsport Park, where both Johnny O’Connell and teammate Michael Cooper struggled, in track Category C configuration.

The changes only affect the car’s top-end RPM range, which will likely benefit the pair of ATS.V-Rs on the high-speed track.

Road America sees a switch back to SRO’s Category B BoP, the same configuration used at Circuit of The Americas, but with some notable changes to other cars since the season-opener as well.

Among them are weight adjustments for the Aston Martin V12 Vantage GT3 (+40kg), McLaren 650S GT3 (+5kg), Porsche 911 GT3 R (-10kg), although the Porsche also receives a 3mm x2 reduction in air restrictor, compared to its configuration at COTA.

Road America and COTA are the only Category B tracks in the PWC season.

O’Connell and Cooper have slipped to third and fourth in the GT championship, following disappointing results at CTMP and Lime Rock under the previous BoP.

Official track action at Road America kicks off on Friday, although there is a promoter test day scheduled for Thursday.