***Intermittent showers greeted IMSA WeatherTech SportsCar Championship teams on Thursday, in what’s marked a continuation of wet weather to impact each round this year, with the exception of Long Beach.

***Forecasts currently call for a 40 percent chance of rain on Friday, with scattered thunderstorms in store for Saturday afternoon, around the 12:30 p.m. EDT start time for the 100-minute race, which will air live on NBCSN.

***The No. 76 Compass Racing McLaren 720S GT3 is the only car to have undergone a Balance of Performance change since Mid-Ohio, with a 9-liter increase in fuel capacity to the mid-engined beast, in an effort to equalize the car’s stint length with the GT Daytona class competitors.

***It’s resulted in the Karl Thomson-led squad having to go with a larger sized refueling restrictor, which teams have been able to choose in order to meet the 40-second minimum refueling time for full loads.

***It’s understood that IMSA will not make any potential performance-related BoP changes to the McLaren until after collecting data from its first three races in series competition, meaning a change is unlikely until Lime Rock Park.

***Compass completed single-day tests at Sebring and Road Atlanta with drivers Paul Holton and Matt Plumb and have a test at Canadian Tire Motorsport Park scheduled for next month.

***A number of other teams also went testing since Mid-Ohio, including Acura Team Penske, Porsche GT Team, Wayne Taylor Racing, CORE autosport and Mazda Team Joest at Watkins Glen in mid-May, with Land Motorsport, Magnus Racing and BMW Team RLL testing there one week later.

***CORE autosport has switched Nissan DPi chassis, with chassis No. 2 to be used from this weekend forward, according to race engineer Jeff Braun. The team purchased both of the Ligier Automotive-built cars from Extreme Speed Motorsports, which Braun says have now been made more-or-less identical.

***Michelin returns to the Detroit race for the first time since 2008, and will mark the street course debut of its Pilot Sport GT S8M commercial race tires for GTD. As was the case in Long Beach, DPi cars will be utilizing Michelin’s ‘Medium’ compound and will have nine sets to utilize over the weekend, compared to six for GTD teams.

***Only a single driver, Patrick Long, took part in the 2008 ALMS race and is on the grid this weekend, showing the considerable turnover in driver and teams in the U.S. sports car racing scene. However, that race featured a number of GT Le Mans drivers that are still active in IMSA, but not racing this weekend due to the two-class format.

***Michelin Motorsports North America technical director Ken Payne said “we might as well consider that we’ve never been here” owing to its 11-year hiatus from the 2.498-mile circuit. “They are new cars and a completely different generation of tires from when we were last here,” Payne said.

***Porsche, which has only a single entry in the No. 73 Park Place Motorsports Porsche 911 GT3 R of Patrick Long and Zach Robichon, nearly lost its streak of competing in every eligible IMSA-sanctioned race since 1971, had Park Place not made the decision to enter the WeatherTech Sprint Cup-only round.

***The German manufacturer has two full-season GTD entries in Park Place and Pfaff Motorsports, although Detroit does not count towards the regular championship. Additionally, the GTLM class is not in action this weekend, with Porsche’s North American-based factory squad in France for the Le Mans Test Day.

***While not driving this weekend, Patrick Lindsey will again be serving as “pilot in command” for nearly a dozen IMSA drivers and support staff heading to Le Mans directly after Saturday’s race. Lindsey, a pilot and owner of Mira Vista Aviation, will charter Long, Renger van Der Zande, Pipo Derani, Oliver Jarvis, Harry Tincknell, Jonathan Bomarito, Filipe Albuquerque, Ricky Taylor and Multimatic’s Larry Holt to France.

***The private flight is scheduled to depart from an airport in Pontiac, Mich. less than two hours after Saturday’s checkered flag and land in Arnage, France at 7 a.m. local time on Sunday.

***Alessandro Balzan said his return to driving last week at Buttonwillow was a “special day” adding to the fact he shook down a Scuderia Corsa-run Ferrari 488 Challenge car that was signed by the late Niki Lauda, and has since been put into a tribute livery. The car, owned by Thomas Tippl, is due to be run in that livery at the next round in Montreal.

***While Victor Franzoni is making his DPi debut this weekend in Juncos Racing’s Cadillac DPi-V.R., the Road to Indy star actually took part in January’s Rolex 24 at Daytona in Via Italia’s Ferrari 488 GT3 car that claimed class pole in the hands of Marcos Gomes.

***IMSA will announce its expanded “IMSA Green” initiatives tomorrow in a press conference in Detroit. The program, which is understood to be in partnership with the U.S. Environmental Protection Agency, will “aggressively pursue” green racing protocols and will “considerably” reduce the championship’s carbon emissions and overall environmental footprint.

***Sportscar365 understands that among the initiatives that have been under consideration include the use of renewable fuels for auxiliary machinery, such as generators, as well as the potential use of solar power. It’s unclear if IMSA will officially confirm hybrid powertrains for DPi 2.0, as previously revealed by Sportscar365, during the press conference.

***U.S. EPA Transportation and Climate Division Director Karl Simon will be in attendance alongside IMSA President Scott Atherton, who had played a large part in aligning several U.S. government organizations in the American Le Mans Series’ green racing initiatives that included the Michelin GreenX Challenge.

***It’s understood the next DPi 2.0 steering committee meeting is scheduled for the week of the Sahlen’s Six Hours of The Glen, at IMSA’s headquarters in Daytona Beach, Fla.

***Recently appointed Michelin Motorsports global director Matthieu Bonardel is getting his first taste of North American off-road racing this weekend, in attending the Baja 500. BF Goodrich-shod vehicles scored eight class victories in the event last year.