Lag is a persistent challenge for turbocharged engines, and the various methods people have employed to combat it are quite remarkable. Techniques range from twincharging to cold-air antilag systems, integrating an MGU-H, or even using a single turbo for each cylinder. Amidst this debate over the most effective solution, one should appreciate that no single approach has dominated the others. After all, if a universal fix had been found, we might never have witnessed the innovation of transforming a helicopter’s turbine engine into a completely lag-free turbo that can maintain maximum boost at all times.
This innovation is exemplified by the Mannic-Beattie, a one-of-a-kind British hillclimb vehicle developed by Nic Mann and John Beattie. Built on a Clubman chassis, a type of budget-friendly open-wheel car, it features a decidedly advanced drivetrain. The vehicle is equipped with all-wheel drive, powered by a modified 1.7-liter version of the Cosworth BDT four-cylinder engine, originally from the Ford RS200, a renowned Group B rally car. However, the standout feature of this machine is undoubtedly its turbo, which is effectively a standalone jet engine converted to provide boost.
Beattie himself elaborates on this innovative setup on his website, RaceEngineDesign.co.uk. At its core is a compact turbine engine known as an air start unit (ASU), commonly employed to start larger turbine or jet engines in helicopters and planes. The fundamental mechanics of turbine and jet engines are strikingly similar, differing mainly in how the generated power is utilized. Turbines (or turboshaft engines) harness the energy from a spinning shaft, while jet engines utilize exhaust thrust. This similarity allows for a turbocharger to be converted into a jet engine, as the former is essentially a turbine-driven compressor. The Mannic-Beattie employs this concept in an unconventional manner.
The process begins with the driver starting the Cosworth four-cylinder engine to circulate oil through the helicopter turbine. Subsequently, compressed air from an external source is fed into the turbine to accelerate it to 10,000 rpm, generating one psi of boost. At this point, the ASU’s independent fuel system and ignition are activated, ramping it up to five psi, at which point it becomes self-sustaining. Beattie noted that the original design faced challenges with cutting out during gear shifts due to drops in boost, but those issues have since been resolved. Interestingly, this engine operates at an idle of five psi boost.
Details about the complete system remain somewhat elusive. Photos from Beattie’s website do not provide a clear view of the intake plumbing, and a recent Instagram video featuring McMurtry Speirling test driver Alex Summers fails to clarify the setup fully. It is evident that the Cosworth engine’s exhaust manifold directs exhaust to the hot side of the ASU, while the compressor, sourced from a heavy-duty truck, supplies boost to both the engine and the turbine. It’s likely that a diverter valve exists between the intake and exhaust manifolds to maintain turbine operation at closed throttle—though details on this mechanism remain uncertain.
What is evident, however, is the remarkable performance attributed to this unconventional setup.
Thanks to the turbine’s ability to operate independently of the Cosworth piston engine, it can achieve 40 psi of static boost even with the throttle closed. This results in an extraordinary torque curve, delivering 80 percent of peak torque between 2,500 and 7,500 rpm as it approaches its 9,000 rpm limit. The power output is estimated to be around 600 hp, an impressive figure for a vehicle that weighs approximately 1,400 pounds. Consequently, it can accelerate from 0 to 60 mph in about two seconds.
As a hillclimb car, it also features a well-calibrated chassis to effectively harness its power. The modified Mallock open-wheeler frame achieves a 50-50 static weight distribution and boasts significant aerodynamics, including a Formula 1-inspired exhaust-blown diffuser. This combination results in a formidable hillclimb vehicle, as evident in videos showcasing its performance.
Given the effectiveness of a turbine-boosted engine, it is easy to envision this concept being used in other racing vehicles. However, bringing this idea to fruition can be quite challenging due to the added complexity and the introduction of another high-heat source. Nevertheless, one can only hope that the Mannic-Beattie will not stand alone in utilizing a small turbine engine as a turbocharger. Perhaps the creators of a real-world Red Bull X2010 should consider this innovative approach.
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