HPD ARX-04b

HPD ARX-04b

Category	Le Mans Prototype (LMP2)
Constructor	HPD (Wirth)
Designer(s)	Nick Wirth
Predecessor	HPD ARX-03b
Successor	Acura ARX-05
Technical specifications [1] [2]
Chassis	Carbon fibre composite monocoque
Suspension (front)	Double wishbones, push-rod actuated coil springs and four-way adjustable dampers, anti-roll bar
Suspension (rear)	Double wishbones, push-rod actuated coil springs and four-way adjustable dampers, anti-roll bar
Engine	Honda HR28TT 2.8 litre V6 twin turbo mid-engined, longitudinally mounted
Transmission	6-speed sequential manual
Weight	900kg
Fuel	Shell
Tyres	Continental
Competition history
Notable entrants	Extreme Speed Motorsports
Notable drivers	Ed Brown Jon Fogarty Johannes van Overbeek Scott Sharp Ryan Dalziel David Heinemeier Hansson
Debut	2015 24 Hours of Daytona
Races Wins Poles F/Laps 2 0 0 0
Constructors' Championships	0
Drivers' Championships	0

The HPD ARX-04b is an LMP2 race car designed and built by Wirth Research for Honda Performance Development. The car was designed as the successor to the HPD ARX-03 series of Le Mans Prototypes, however the poor performance of the car meant that the older model outlived the ARX-04b, and the 04b only contested one race, the 2015 24 Hours of Daytona.

Racing history

The car was designed to meet the new set of LMP2 regulations, starting in 2014. Two cars were delivered to its sole customer, Extreme Speed Motorsports, in December 2014, where it soon began testing. ^[2] The team intended to use the cars in the 2015 United SportsCar Championship, starting at the 24 Hours of Daytona. The cars were uncompetitive during the race, and both cars failed to reach the finish. The #1 car managed to complete 389 laps to the winners 740, but the #2 car managed only 50.

Following the disappointment of Daytona, Extreme Speed Motorsport decided to take time to test the car further, opting to race the older HPD ARX-03b at Sebring. The team remained unsatisfied with the car, and chose to replace them with the Ligier JS P2. ^[3] Daytona remains the only race outing of the ARX-04. HPD continued to test and develop the car, to try and resolve aerodynamic problems and improve its performance.

The ARX-04 was also entered into the 2015 Pikes Peak International Hillclimb, with Justin Wilson assigned to drive the car. However, reliability issues meant that the car was unable to drive in the event. ^{[4] [5]}

In 2016, a revised version of the ARX-04b was tested by Michael Shank Racing. Shank later praised the improvements that the car has made. The car was later used by Shank to test the 2017 Continental tyres for the upcoming season ^{[6] [7] [8]}

The ARX-04b made a racing return at the 2023 Silverstone Festival Masters Endurance Legends event, driven by Steve Tandy.

It then returned again in 2024, to race in its 2nd Masters Endurance Legands race and won its class and broke the LMP2 lap record at Donington Park driven by Alfie Briggs

Complete United SportsCar Championship results

(key) Races in bold indicates pole position. Races in italics indicates fastest lap.

Complete United SportsCar Championship results

Year	Entrant	Class	Drivers	No.	Rds.	Rounds										Pts.	Pos.
						1	2	3	4	5	6	7	8	9	10
2015	Tequila Patrón ESM	P	Scott Sharp Ryan Dalziel David Heinemeier Hansson	1	1 1 1	DAY 10	SEB	LBH	LGA	DET	WGL	MOS	ELK	COA	PET	45*	12th*
			Ed Brown Jon Fogarty Johannes van Overbeek	2	1 1 1	DAY 14	SEB	LBH	LGA	DET	WGL	MOS	ELK	COA	PET	42*	13th*
Sources: [9] [10]

* Points were scored with the ARX-03b

References

1. "HPD ARX-04 Specifications". "Ultimate Car Page". Retrieved 2016-08-20.
2. "HPD ARX-04 Specifications". "Racecar Engineering". Retrieved 2016-09-06.
3. "HPD ARX-04 replaced by Ligier". "Autosport". Retrieved 2016-10-10.
4. "HPD ARX-04 Entered at Pikes Peak". "Motorsport.com". Retrieved 2016-10-10.
5. "HPD ARX-04 withdrawn from Pikes Peak". "Autoblog.com". Retrieved 2016-10-10.
6. "HPD ARX-04 to be tested by Shank". "Sportscar365.com". Retrieved 2016-10-10.
7. "Shank impressed with ARX-04". "racer.com". Retrieved 2016-10-10.
8. "HPD ARX-04 Tyre Test". "Sportscar365.com". Retrieved 2016-10-10.
9. "2015 TUDOR Championship Points Standings - Official.pdf" (PDF). Archived from the original (PDF) on 4 March 2016. Retrieved 17 May 2024.
10. "Complete Archive of HPD ARX-04". Racing Sports Cars. pp.  1 . Retrieved 17 May 2024.