IMSA has released a pair of pre-race Balance of Performance adjustments to the GT Le Mans class, one with immediate effect before next week’s Prototype/GTLM race at Long Beach, and another before the all-class round at Mazda Raceway Laguna Seca in May.

The BMW Z4 GTE has several adjustments coming. Going into Long Beach, the BMW will be 10 kg lighter, now at 1210 kg.

At Mazda Raceway, the car will have modified door sills and also be permitted to reduce the width of its rear diffuser plate, from 2007 mm to 1883 mm.

Fuel tank capacities have also been adjusted for all GTLM cars going into the 100-minute Tequila Patron Sports Car Showcase at Long Beach.

Ferrari (+4 liters), Porsche (+3) and BMW (+2) will all have fuel tank increases, with Chevrolet’s tank capacity decreasing by 3 liters. Those capacities will stay the same at Mazda Raceway.

The other GTLM change that will take effect going into Mazda Raceway will affect the Ferrari F458 Italia. The Ferrari will have a 0.3 mm restrictor decrease and a 15 kg weight addition, but will be permitted the use of its 2015 evolution splitter and diffuser, and a permitted use of electronic fly-by-wire throttle.

It remains to be seen whether there will be any further BoP adjustments revealed before IMSA’s two-race California swing.