On May 5, 2021, the entry list for the event was released, featuring a total of 26 cars across three classes. Six cars were in Daytona Prototype International (DPi), another six entries were in the Le Mans Prototype 3 (LMP3) class, and 14 entries were received for the GT Daytona (GTD) class. The GT Le Mans (GTLM) and Le Mans Prototype 2 (LMP2) classes were not present. In the GTD class, several teams who were scheduled to be present only at the 3-hour rounds on the 2021 calendar made their season debut, including CarBahn Motorsports and Compass Racing, the former of which was making the step up from the IMSA SportsCar Championship support category, the Michelin Pilot Challenge.[2][3][4]
This race also marked the start of the season for full-time Wright Motorsports driver, Ryan Hardwick, after suffering crashes that put him out of both the 24 Hours of Daytona and the 12 Hours of Sebring due to concussion. In those two races without Hardwick, Wright Motorsports built up a points lead in the GTD class.[5]
On May 5, 2021, IMSA released a technical bulletin regarding the Balance of Performance constraints for the Mid-Ohio race.[6] The Mazda RT24-P was given a slight power boost, with the equivalent of a 7.5 horsepower increase in engine output through turbo boost levels. After winning at Daytona and Sebring, the Acura ARX-05 and Cadillac DPi-V.R respectively were each given a 1.0 liter reduction in fuel capacity.
In the GTD class, after finishing in the top two places at the 12 Hours of Sebring, the Porsche 911 GT3 R was made 20 kilograms heavier, bringing the standard weight to 1,320 kilograms. A similar change was made to the Acura NSX GT3 Evo, with a 10 kilogram weight reduction after best finishes of 11th and 4th at Daytona and Sebring respectively.
Forty7 Motorsports and Grasser Racing Team withdrew from the event prior to the first practice session.[7]
Practice
There were two practice sessions preceding the start of the race on Sunday, one on Friday and one on Saturday. The first session on Friday afternoon lasted one hour while the second session on Saturday morning lasted 75 minutes.[8]
Practice 1
The first practice session took place at 4:30 pm ET on Friday and ended with Pipo Derani topping the charts for Whelen Engineering Racing, with a lap time of 1:11.846, ahead of the No. 10 Acura of Ricky Taylor.[9] Colin Braun set the fastest time in LMP3 with a lap time of 1:17.240.[10]Jack Hawksworth was fastest in GTD with a time of 1:20.513, 0.291 seconds faster than Bill Auberlen's No. 96 BMW.[11] The session was red flagged early for ten minutes after Jarett Andretti stopped on track.[10]
Qualifying was broken into four sessions.[8] The first was for cars in the GTD class. Aaron Telitz qualified on pole for the class driving the No. 14 car for Vasser Sullivan Racing, beating Robby Foley in the No. 96 Turner Motorsport entry by 0.006 seconds. Daniel Morad in the No. 28 Mercedes was third followed by Frankie Montecalvo in the No. 12 Lexus.[19]
The second session was the points paying session for the GTD class. Patrick Long set the fastest time and earned 35 championship points. Long was 0.126 seconds clear of Zach Veach in the No. 12 Lexus followed by Laurens Vanthoor in the No. 9 Pfaff Motorsports Porsche.[20][19]
1 The No. 60 Meyer Shank Racing with Curb-Agajanian entry initially qualified third for the DPi class. However, the team changed engines. By IMSA rules, the entry was moved to the rear of the DPi field on the starting grid. Additionally, the team elected to change tires after qualifying.[26]
2 The No. 5 JDC-Mustang Sampling Racing entry was moved to the back of the DPi field as per Article 40.1.4 of the Sporting regulations (Change of starting tires).[26]
3 The No. 01 Cadillac Chip Ganassi Racing entry was moved to the back of the DPi field as per Article 40.1.4 of the Sporting regulations (Change of starting tires).[26]
4 The No. 38 Performance Tech Motorsports entry initially qualified fourth for the LMP3 class. However, the car suffered an engine failure during qualifying, forcing the team to use its IMSA Prototype Challenge chassis due to a lack of spare engines. By IMSA rules, the entry was moved to the rear of the LMP3 field on the starting grid.[27]
5 The No. 91 Riley Motorsports entry was moved to the back of the LMP3 field as per Article 40.1.4 of the Sporting regulations (Change of starting tires).[26]
6 The No. 9 Pfaff Motorsports entry was moved to the rear of the GTD classification for violating competition rules regarding the car's ride height.[28]
7 The No. 44 Magnus Racing entry was moved to the back of the GTD field as per Article 40.1.4 of the Sporting regulations (Change of starting tires).[26]
Race
Post-race
With a total of 1,070 points, Albuquerque and Taylor's victory allowed them to extend their lead in the DPi Drivers' Championship over Jarvis and Tincknell to 55 points. Derani and Nasr advanced from seventh to fourth while Cameron and Pla dropped from fourth to fifth.[29] As a result of winning the race, Robinson took the lead of the LMP3 Drivers' Championship. Lindh and Goldburg advanced from tenth to fourth while Askew jumped from seventh to fifth.[29] With 920 points, Auberlen and Foley's allowed them to take the lead of the GTD Drivers' Championship. Sellers and Snow advanced from seventh to fifth while Long dropped from first to third.[29] Porsche continued to top their respective Manufactures' Championship while Acura took the lead of the DPi Manufactures' Championship.[29] WTR-Konica Minolta Acura kept their advantage in the DPi Teams' Championship while Riley Motorsports and Turner Motorsport became the leaders of their respective class Teams' Championships with nine races left in the season.[29]