The season is winding down for IMSA’s WeatherTech SportsCar Championship as three of its five classes descend upon the streets of Long Beach for Saturday evening’s 100-minute Acura Grand Prix.

Six prototypes from the DPi category, three from the outgoing GT Le Mans class, and an exceptional 17 GT3-based cars in GT Daytona comprise the 26 entries set to take the green flag at 5:05 p.m. ET on NBCSN.

In the fastest class, two Acura ARX-05s, with engines built in the nearby town of Valencia at Honda Performance Development, will race against another local product with Mazda and its RT24-P, which is managed from Mazda North America’s Southern California base in Irvine.

The three Japanese cars will face three Cadillac DPi-V.Rs that are overseen from General Motors’ offices in Michigan, and across the three brands, a close fight for drivers’, teams’ and manufacturers’ championships is brewing at the penultimate round. If Cadillac or Mazda have designs on overtaking Acura, Wayne Taylor Racing, and drivers Ricky Taylor and Filipe Albuquerque, they can’t afford to lose the race in Long Beach.

GTLM continues its farewell tour with Corvette Racing’s C8.Rs and WeatherTech Racing’s Porsche 911 RSR leading the charge. Corvette remains poised to cement its hold on all three championship categories over the final three races for IMSA’s GT classes.

Once again, GTD is where the fireworks are expected to be found with a huge grid and thin margins separating the top four programs in the standings. BMW, Porsche, Aston Martin and Lamborghini all have decent shots at coming out on top as Turner Motorsport leads the class, followed by Pfaff Motorsports, The Heart of Racing, and Paul Miller Racing.

Like GTLM, there’s enough racing left in the season for front-running GTD teams to enter Long Beach without feeling an abundance of pressure to win at all costs, but with a narrow track, wide cars, and an inherent difficulty in passing without making contact, adversity could easily shuffle the championship standings by the time the checkered flag waves.