Using Turbochargers Can Have Adverse Effect on Engines

Many automotive manufacturers use turbochargers to provide greater fuel efficiency without comprising performance. Turbochargers have become more and more popular as they allow motorists to have the best of both worlds. However, using turbochargers might cause significant damage to the engine, according to Joachim Wagenblast, director of R&D-engine systems and components for engine supplier Mahle USA, who spoke about this at a technology presentation named, “Problems Ahead for New Fuel-Efficient Engines”.

When turbochargers are used, the smaller engines must produce high torque at low speeds to facilitate downspeeding or change of gear ratios to lower engine speed in order to achieve better fuel economy. The pressure needed to achieve these high levels of low-speed torque and quick responsiveness from the throttle can result in an abnormal combustion phenomenon that is known as low-speed pre-ignition (LSPI) which creates extremely high pressures in the combustion chamber. LSPI can break off the tops of pistons and lead to bent connecting rods and broken piston rings.

Factors like aggressive driving and towing can contribute to LSPI. With government norms regarding fuel economy becoming increasingly strict across the world, turbocharged engines have become highly popular. These engines can be 30% smaller when compared to their naturally aspirated equivalents. By 2025, over 50 per cent of the vehicles sold in the United States are expected to have downsized engines.

Mahle is working on possible solutions for LSPI which include stronger parts and more durable coatings. Mahle is working on both. Wagenblast said that the company recently incorporated a high-strength ring carrier in a piston’s first ring groove to help prevent LSPI-related part failures.

He said, “Our development teams are focused on creating engine components and systems designed to withstand low-speed, pre-ignition events, as well as assist in preventing their occurrence.”

Mahle is also developing advanced test protocols aimed specifically at LSPI.