Following an eight-year development program, the UK-based firm Controlled Power Technologies (CPT) has shown an electric supercharger package designed specifically for volume-production automotive applications. According to CPT, the Variable Torque Enhancement System (VTES) can be used on both gasoline and diesel engines -- and can even be combined in series applications with a normal exhaust-driven turbocharger. CPT claims its VTES setup offers an extremely cost-effective way to enhance a vehicle's real-world performance and economy while significantly trimming greenhouse gas emissions.
Unlike a conventional supercharger that builds boost by spinning its impellers with a belt driven by the crankshaft, the VTES unit uses pure electric power to force a bigger charge of intake air into the cylinders. According to CPT's internal testing, the system can generate the performance of a naturally aspirated 2.0-liter engine from just 1.2 liters of displacement while delivering 40-percent better acceleration times than a non-supercharged engine of that size.
The key to the overall responsiveness and efficiency of the VTES is its immediacy. Because the low-inertia compressor operates independently from the engine, that element can be spun up from 5,000 rpm to its maximum 70,000-rpm boost mode in less than 300 milliseconds. That translates to less than 10 combustion cycles, far quicker than any belt-driven force-feeder. CPT says the VTES System is particularly well-suited to diesel engines, where it also helps further reduce CO2 emissions levels. Controlled Power Technologies recently contracted with another British firm, Switched Reluctance Drives, Ltd, to start developing the VTES package for large-scale automotive applications.