A three-hour showcase event for the IMSA Prototype Challenge takes place this weekend at Canadian Tire Motorsport Park.

The three-hour race is actually 20 minutes longer than the IMSA WeatherTech SportsCar Championship Mobil 1 SportsCar Grand Prix presented by Acura.

The fourth round of the IPC season sees a clear two-horse race at the front of the championship battle.

Austin McCusker and Rodrigo Pflucker are yet to win this year but hold a four-point lead in the standings on the strength of their consistency. They share the No. 47 Norma M30 for Forty7 Motorsports.

Similar to Mid-Ohio, Neil Alberico has track experience at CTMP from his formative years in the Road to Indy open-wheel ladder. Alberico and Leo Lamelas sit four points back, matching their car number in the No. 4 ANSA Motorsports Ligier JS P3.

Both teams enter with optimism. Lamelas scored the pole last year and he and his co-driver (Roman de Angelis) finished seventh on the road before they were dropped to the rear of the field following post-race technical inspection.

Forty7 won this race last year with McCusker and TJ Fischer driving. Pflucker has a pole this season at Sebring.

Others to watch

Other drivers to watch include Garett Grist, who was on the podium here last year, and will share the No. 51 K2R Motorsports Ligier. The team’s sister car has a driver change this weekend with English driver Matt Bell taking over the No. 64 car alongside Naveen Rao for the remainder of the season.

The No. 54 MLT Motorsports car enters with the most amount of momentum as Dylan Murry and Dakota Dickerson won the series’ most recent race at Mid-Ohio two months ago.

Murry, who’s been on a roll of late as one of IMSA’s strongest young drivers under 21, is also fresh off his maiden IMSA MICHELIN Pilot Challenge win at Watkins Glen last week, sharing the No. 35 Riley Mercedes-AMG GT4.

Kenton Koch is also back as a third driver with Polestar Motor Racing. The Robillard Racing team is back to a single car for the three-hour race with Sebring winner Stevan McAleer and Joe Robillard. McAleer and Koch shared the No. 10 Norma M30 at Daytona.

Two teams add second cars, with ONE Motorsports (Mikel Miller, Benjamin Waddell) and PR1/Mathiasen Motorsports (Jonatan Jorge, Joel Janco) in separate Ligier JS P3s.

The IMSA PC race runs Saturday at 4:30 p.m. EDT with live coverage on IMSA.TV, with IMSA Radio commentary.