Toyota is making a significant push into Australia’s Repco Supercars Championship, but their entry isn’t built from scratch. Instead, it relies on a sophisticated reimagining of a nearly two-decade-old engine. Through a technical partnership between UK-based Swindon Powertrain and Australia’s Walkinshaw TWG Racing, a veteran Lexus V8 has been transformed into a competitive Gen3 Toyota GR Supra racing heart.
The Foundation: Breathing New Life into the 2UR-GSE
The core of this project is the Toyota 2UR-GSE, a 4.9-liter V8 that first debuted in 2007. While originally designed for high-end Lexus road cars, its inherent durability made it an ideal candidate for the grueling demands of Supercars racing.
To maximize the engine’s potential within the series’ technical regulations, engineers focused on three critical areas: displacement, fuel delivery, and valve timing.
Key Technical Transformations
1. Achieving the “Square” Configuration
Supercars regulations permit engine displacements of 5.0 or 5.7 liters. To reach this threshold without compromising the integrity of the existing engine block, Swindon Powertrain opted for a strategic redesign of the internal geometry:
– The Modification: They replaced the standard crankshaft with a new version, increasing the stroke from 89.5mm to 94mm.
– The Result: This created a “square” configuration—where the bore and stroke are equal—optimizing the engine’s balance and power delivery while remaining fully compliant with the rules.
2. From Direct to Port Injection
One of the most significant hurdles was the series’ ban on direct injection. Since the original 2UR-GSE relies on direct injection, the entire induction system had to be overhauled:
– The Conversion: Engineers “deleted” the original injector bores in the cylinder head and replaced them with a new port injection system.
– Advanced Manufacturing: The new inlet system features a 3D-printed intake manifold. This technology, used successfully by Swindon in the British Touring Car Championship (BTCC), utilizes 3D-printed plastic and machined components to ensure perfect airflow distribution and optimal acoustic tuning for the torque curve.
– Combustion Refinement: Because port injection changes how fuel enters the cylinder, the combustion chambers were redesigned to ensure efficient burning and reliable performance.
3. Solving the VVT Dilemma
Modern production engines use electronic systems for Variable Valve Timing (VVT) to optimize efficiency. However, Supercars mandates a standardized, sealed ECU that does not support these electronic systems.
– The Solution: Swindon developed a custom hydraulic VVT system for the intake cams to mimic the original’s functionality. This required a complete redesign of several components, including cam caps, cam covers, and oilways.
Efficiency Through Hybrid Engineering
Despite the extensive list of modifications, the project follows a philosophy of strategic retention. By keeping the majority of the original production components, the team achieves two goals:
1. Regulatory Compliance: Staying within the strict framework of the Gen3 rules.
2. Cost Management: Reducing the complexity and expense of building a bespoke racing engine from zero.
While the intellectual property and design work originated in the UK, the physical assembly and ongoing maintenance are handled locally at Walkinshaw TWG Racing’s facility near Melbourne, ensuring the Toyota GR Supras are ready for the track.
This engineering feat demonstrates how “old” technology can be rendered highly competitive through modern additive manufacturing and precise mechanical redesign, proving that longevity in automotive design is a matter of evolution rather than replacement.
