Technical Research Archive V8 Supercars
Cars / Group 3A / VR Commodore
Holden · Group 3A

VR Commodore

1995-1996 · 22/41 specifications catalogued

Reported 125 mm reduction needs the CAMS bulletin, datum and effective date.

The Holden VR Commodore was Holden's Group 3A V8 Supercar for 1995 and 1996, replacing the VP Commodore and giving way to the VS Commodore for 1997. This page describes the selected post-September 1996 revised package.

Development

The VR wrapped updated bodywork around the same fundamental Group 3A mechanical package as the VP: a naturally aspirated, fuel-injected Holden 5.0-litre V8 turning to the regulated 7500 rpm, a Holinger six-speed and a 9-inch live rear axle. Whether — and when — the racing Commodore's engine moved from Holden's own V8 to a Chevrolet-based small-block is disputed and left unresolved in the project's conflict register (CON-006); in period it is recorded as the Holden 5.0-litre unit.

Body & aero

The VR's most visible change was a centre-post rear wing in place of the VP's side-mounted arrangement — the wing style the VS would carry over. The front kept the mandated large spoiler and inverted-wing undertray. The selected state is the post-September 1996 revised package: ahead of that year's Sandown 500 the front spoiler and undertray were cut by a reported ~125 mm on parity grounds. That is a dimensional change identifying the amendment, not a downforce figure — the original CAMS bulletin and reference datum remain unrecovered, so no force delta should be read from the cut length.

Chassis & driveline

Suspension followed VP practice: a MacPherson-strut front and a live rear axle located by a four-link and a Panhard rod on a Ford 9-inch-based housing. The Watts-linkage rear that defined the later VT had not yet appeared. Drive ran through the Holinger six-speed to the 9-inch crown-wheel-and-pinion. Category minimum weight rose to 1350 kg for 1996.

Brakes, wheels & tyres

Wheels were the 17×11 category size; early Group 3A cars ran various custom wheels rather than a single make. Tyres remained an open competition between Bridgestone, Yokohama, Dunlop and Hoosier — the control-tyre era was still three years off. Brakes and pads followed team practice.

Evolution

The VR handed over to the VS Commodore for 1997, which added a new front bar to the same VP-derived platform and kept the centre-post wing.

For its championship record see the 1995 and 1996 seasons. Sources: Group 3A formula and the V8 Supercars Physics Handbook (N. Higginson) — Grade B; VR aero states and the engine-transition dispute (CON-006) — Grade D.

Technical specification

Grouped by system. Every value carries its confidence grade and source.

confirmedperiod-verifiedbridge refunknownquarantined

Category 0/2

Formula designation
unknown
Series & administration
unknown

Engine 6/8

Displacement
5.0 L confirmed
Div C Technical Rules (2003, harvested): max engine capacity 5000cc; formula continuous from the period
Configuration
90-degree V8 period-verified
Group 3A formula
Induction
Naturally aspirated; fuel injection standard from 1993 period-verified
Group 3A formula; V8 Sleuth; V8 Supercars Physics Handbook (N. Higginson) · Exception: the 1993 Moffat Cenovis EB ran a Holman & Moody carburettor before switching to EFI in 1994
Power (est.)
unknown
Max engine speed
7500 (regulated limit) rpm confirmed
Div C Technical Rules C 6.6.1 (2003, harvested): controlled 7500 rpm limit
Compression ratio
10:1 confirmed
Div C Technical Rules C 6.2.1 (2003, harvested): compression ratio must not exceed 10.0:1; V8 Supercars Physics Handbook (N. Higginson)
Engine management
unknown
Engine block
Holden 5.0-litre V8 period-verified
1993 ATCC research (Wikipedia; Supercars.com; Shannons Club); 1995-97 research · Holden's own 5.0L V8 in period; Chevrolet-based small-block architecture adopted later - transition timing disputed (see CON-006)

Drivetrain 4/4

Gearbox
Holinger H6S 6-speed (standard); 5-speed Getrag in some privateer cars period-verified
V8 Supercars Physics Handbook (N. Higginson); Holinger official history; V8 Sleuth
Gear ratios
Holinger 6-sp: 2.571 / 2.000 / 1.667 / 1.350 / 1.143 / 1.000; Getrag 5-sp: 3.51 / 2.08 / 1.35 / 1.00 / 0.81 (rev 3.71) confirmed
Getrag/Holinger ratio set (project mod gearbox files; see Simulator notes)
Final-drive options
3.25 / 3.5 / 3.7 confirmed
2002 V8Supercars.com VX & AU specs; 2004 AU/VX specs (FND-011/037) · Period-confirmed for 2002 by the official VX and AU spec pages; the same set is used in the mod gearbox files (Simulator notes)
Differential
9-inch crown wheel & pinion (fabricated assembly, fixed ratios) period-verified
2002 V8Supercars.com VX & AU specs (FND-037); 2004 AVESCO specs · Period-confirmed 2002; early Commodores used a Ford F100 truck 9-inch diff housing

Suspension 5/8

Front type
MacPherson strut period-verified
model architecture
Rear type
Live axle period-verified
model architecture
Front spring rate
78.8-175.1 (400/500-900/1000 lb; circuit-dependent) N/mm period-verified
Jack Perkins, Perkins Engineering · Real figures are in pounds (Perkins); N/mm shown for engineering use
Rear spring rate
40.3-87.6 (230-500 lb; circuit-dependent) N/mm period-verified
Jack Perkins, Perkins Engineering
Anti-roll bars
Cockpit-adjustable from 1994; 2nd blade ~1999-2000; both blades 2008 period-verified
Jack Perkins, Perkins Engineering · 2008 is post-period
Dampers
unknown
Front geometry
unknown
Rear geometry
unknown

Brakes 1/5

Front disc
unknown
Rear disc
unknown
Front caliper
unknown
Rear caliper
unknown
Brake pads
Ferodo DS3000 (Perkins Engineering) period-verified
V8 Supercars Physics Handbook (N. Higginson) / Perkins

Wheels & tyres 3/4

Wheel size
17 x 11 in period-verified
Standard rolling stock from 1993 (Wikipedia; JAX Tyres) · Diameter/width is category-standard; wheel supplier/brand varied by team, and earlier Group 3A cars ran various custom wheels
Tyre supplier
Open competition: Dunlop, Yokohama, Bridgestone, Hoosier period-verified
Control-tyre chronology; V8 Supercars Physics Handbook (N. Higginson)
Tyre dimensions
12-inch-wide tyres on 17 x 11 rims period-verified
Standard rolling stock from 1993 (Wikipedia)
Tyre construction
unknown

Weight 0/2

Minimum weight
unknown
Weight distribution
unknown

Fuel 1/2

Fuel capacity
120 L confirmed
Div C Technical Rules (2003, harvested): fuel tank max 115 L, TEGA checking vessel 120 L; 2000 cost page; V8 Supercars Physics Handbook (N. Higginson)
Fuel specification
unknown

Dimensions 0/3

Wheelbase
unknown
Front track
unknown
Rear track
unknown

Aerodynamics 2/3

Front aero
Front spoiler + undertray shortened ~125 mm (post-Sep-1996 parity cut) period-verified
1995-97 research (Shannons Club; V8 Sleuth; Wikipedia) · Selected state; dimensional cut, not a downforce figure
Rear wing
Centre-post rear wing (replacing the VP side-mount) period-verified
1995-97 research (Shannons Club; V8 Sleuth; Wikipedia)
Downforce / drag map
unknown