Built by HPD and Oreca from 2018, the ARX-05 won the Daytona 24 Hours twice and gave Acura three manufacturers' titles across five seasons.
The Acura ARX-05 is a DPi sports prototype built by Honda Performance Development with Oreca on an Oreca 07 chassis. It raced from 2018 to 2022, won the Daytona 24 Hours twice and gave Acura three manufacturers' titles.
The Acura ARX-05 is a Daytona Prototype International sports prototype developed by Honda Performance Development with Oreca. It began racing in 2018 under the DPi regulations, and it was built around the Oreca 07 LMP2 chassis.
The car raced in five IMSA seasons, from 2018 to 2022, and it was a regular fixture in championship fights. Its wins included two Daytona 24 Hours victories, and three manufacturers' titles came in that span.
Why did Acura return to IMSA prototype racing?
HPD's earlier prototypes had not gone well in IMSA. The ARX-03 was withdrawn in 2014 by Extreme Speed Motorsports over complaints about balance of performance, and the ARX-04b competed only at the 2015 24 Hours of Daytona before it was shelved.
HPD interviewed several chassis makers before reaching an agreement with Oreca. The DPi ruleset had been finalised alongside the 2017 LMP2 regulations, which made an existing LMP2 chassis a practical starting point. The Oreca 07 became the basis for the ARX-05, which was the first car to carry the Acura badge in prototype racing since 2011.
Acura's return was announced in July 2017, with HPD agreeing a deal with Team Penske to run the car from the 2018 season. The ARX-05 was unveiled at Laguna Seca in August 2017.
An Oreca chassis with Acura styling and a twin-turbo V6 gave Acura its return to prototype racing, and three manufacturers' titles followed.
How was the ARX-05 designed?
The ARX-05 was built around the Oreca 07 carbon-fibre monocoque. Acura Design Studio in California styled the bodywork, and the car carried the Jewel Eye headlights from Acura's production models while keeping the standard LMP2 cockpit dimensions and survival cell.
The power unit was the Acura AR35TT, also called the Honda HR35TT. It was a twin-turbocharged 3.5-litre V6 derived from Honda's J35 road engine, and it had previously powered the Ligier JS P2 and the Riley MkXXVI in endurance racing.
A six-speed paddle-shift sequential gearbox by Xtrac transmitted the power. Each wheel had an independent double-wishbone suspension with pushrods, and Brembo six-piston calipers acted on carbon brake rotors.
The car used a rear mid-engine, rear-wheel-drive layout. Its power output was adjusted through IMSA's balance of performance rules, which meant the regulator, not the designer, set the final number.
How was the car tested before its debut?
The first test of the ARX-05 took place at Circuit Paul Ricard in late July 2017, before the public unveiling. Footage from that run was used in an Acura teaser released in August.
The first North American test followed at Road Atlanta, where Juan Pablo Montoya drove over two days. The car made its first run on the Daytona banking in November 2017, a month before IMSA's official test days at the track.
How did Team Penske's 2018 season go?
Team Penske ran two cars in 2018. Car 6 had Juan Pablo Montoya, Dane Cameron and Simon Pagenaud for the endurance races, while car 7 was driven by Helio Castroneves and Ricky Taylor, with Graham Rahal for some races.
Mechanical problems and race damage plagued both cars at the Daytona 24 Hours and the 12 Hours of Sebring. Montoya secured the team's first pole at Long Beach, and performance improved steadily as the year went on.
The breakthrough came at Mid-Ohio, where car 7 scored the ARX-05's first victory, with Castroneves and Taylor leading a 1-2 finish over car 6. Belle Isle brought a double podium, but after that car 7 struggled to return to the podium.
At the end of the season car 6 finished fifth and car 7 seventh in the team standings. Acura finished second in the manufacturers' championship, which was a strong result for a debut year.
What did the 2019 season bring?
The 2019 season was the ARX-05's breakthrough year. Car 6 recorded seven straight podium finishes and won three races at Mid-Ohio, Belle Isle and Laguna Seca, which carried it to the team's championship.
Car 7 did not win a race that year, but it stayed in contention for the title, taking five podiums with only one finish below fifth. Alexander Rossi replaced Graham Rahal as car 7's third driver for the endurance races, while Rahal returned only for the Petit Le Mans.
At the Daytona 24 Hours car 6 had early setbacks and finished sixth, while car 7 achieved a podium. The ARX-05 saw three more double podiums during the year, which helped Acura win its first DPi manufacturers' title.
How did the 2020 season end the Penske partnership?
In 2020 the driver lineups stayed largely the same, with Rossi as the only driver for car 7's endurance rounds. The season opened at the Daytona 24 Hours, where car 6 finished fourth and car 7 eighth, before the COVID-19 pandemic postponed the season.
Car 7 won four of the last six races, while car 6 recorded three podiums in the final three races after a mixed start. Penske and Acura defended their championships, with car 7 winning the team title by a single point and Acura narrowly edging out Cadillac for the manufacturers' title.
The partnership ended after three years. Acura and Team Penske announced in July 2020 that they would part ways once the season was over.
Who ran the ARX-05 after Team Penske left?
From 2021 factory support for the ARX-05 passed to Wayne Taylor Racing and Meyer Shank Racing, which ran cars 10 and 60. Several former Penske drivers returned, and the two teams began a new chapter with the car.
At the 2021 Daytona 24 Hours, Ricky Taylor, Alexander Rossi and Helio Castroneves were back in one team. Taylor ran car 10 full-time, Rossi raced the endurance rounds, and Castroneves drove only at Daytona.
In car 60, Dane Cameron, Juan Pablo Montoya and Helio Castroneves reunited at Petit Le Mans. Cameron ran the car full-time, while Oliver Pla was the second full-time driver and A.J. Allmendinger drove at Daytona.
What were the 2021 results?
Car 10 won the 2021 Daytona 24 Hours by 4.704 seconds over car 48, a Cadillac DPi-V.R run by Action Express Racing. It was the most prestigious victory the ARX-05 had achieved up to that point.
Car 10 stayed a consistent threat through the season, adding six more podiums and wins at Mid-Ohio and Laguna Seca. Car 60 was less competitive, recording only two podium finishes across the year.
Car 10 narrowly lost the team's championship to the Action Express Cadillac, and car 60 finished fifth. Acura finished second to Cadillac in the 2021 manufacturers' championship.
How did the 2022 season end the DPi era?
The 2022 season was the final year of the DPi regulations, and so the final year of the ARX-05. Wayne Taylor Racing kept Ricky Taylor and Filipe Albuquerque as full-time drivers, while Meyer Shank fielded Tom Blomqvist and Oliver Jarvis full-time in car 60.
Car 60 opened the season with the ARX-05's second Daytona 24 Hours victory, topping a double podium with car 10. Car 10 collected five wins that year, including events at Mid-Ohio, Watkins Glen and Road America, plus the Daytona qualifying race and Laguna Seca.
Car 60 did not win again until Petit Le Mans but strung together five straight second-place finishes. Its consistency won it the team title, even though car 10 claimed the most race wins.
Acura won the manufacturers' championship again, which was its third title with the ARX-05. The result tied Acura with Cadillac for the most manufacturers' victories of the DPi era, and Acura had done it in one fewer season.
What were the Acura ARX-05 specifications?
| Specification | Detail |
|---|---|
| Category | Daytona Prototype International (DPi) |
| Developed by | Honda Performance Development with Oreca |
| Chassis | Oreca 07 LMP2, carbon-fibre monocoque |
| Styling | Acura Design Studio, California |
| Engine | Acura AR35TT, twin-turbo 3.5-litre V6 |
| Gearbox | Six-speed paddle-shift sequential by Xtrac |
| Brakes | Brembo six-piston calipers, carbon rotors |
| Debut | 2018 IMSA SportsCar Championship, Team Penske |
| Daytona 24 Hours wins | 2021 (car 10) and 2022 (car 60) |
| Manufacturers' titles | 2019, 2020 and 2022 |
| Team titles | Team Penske (2019, 2020); Meyer Shank (2022) |
| Final season | 2022 |
| Successor | Acura ARX-06, from 2023 |
What replaced the ARX-05?
The ARX-06 replaced the ARX-05 from 2023, when the DPi regulations gave way to LMDh. The ARX-05 had five seasons of competition, from 2018 to 2022, and its final year closed the DPi era for the whole field.
How did the ARX-05 fare against the Cadillacs?
The Cadillac teams were the main rivals through the DPi years. In 2022 the Cadillac entries were the only other DPi cars on the grid, so each Acura result was a direct comparison with the same opposition.
In 2020 Acura edged out Cadillac narrowly for the manufacturers' title, and in 2021 Cadillac took the title ahead of Acura. The 2021 Daytona win came against a Cadillac entered by Action Express Racing, which made that victory a particularly notable one for the ARX-05.
The 2022 season was the most one-sided for the field, since every rival entry was a Cadillac. Even so, the two Acura cars outranked every Cadillac in the team table, despite the numerical disadvantage.
_(cropped).jpg){kind=link}