Mercedes' high-performance division, AMG, has said that it's working on a next-generation electric turbo for future models. The company already has an electric turbocharger in production, on the AMG 53 mild-hybrid six-cylinder engine.
Eliminate turbo lag
AMG says that this development is part of a general move towards electrification, and that it represents a step forward from current e-turbo technology. The great benefit of electric turbos is, of course, the fact that they have much more instantaneous responses than a traditional gas-driven turbo. Gas-driven turbos need time to build up pressure, hence the phenomenon of 'turbo lag' but an electrically-driven turbo can circumvent that delay, eliminating (or at least dramatically reducing) lag.
The new AMG turbo has been developed in co-operation with Garrett Turbocharging (a bit of a legend in the turbo world) and is said to draw on technology developed for the Mercedes-AMG Formula One car.
Cuts the need for twin turbos
Its biggest potential advantage is that it could replace the current trend for two turbochargers - a small, fast-responding one for low engine speeds, and a larger, but slower-responding, one for higher engine outputs.
The new AMG turbo is essentially a hybrid, using electric power for instant, low-down responses, but handing over to exhaust-gas driven compression at higher RPM. By using one, hybrid, turbo such as this, engineers could eliminate the need to have two turbos, thus saving weight, complication, and mechanical drag.
170,000rpm compressor
Driven by a 48-volt electrical system, the AMG electric turbo can also keep pressure in the system when the driver lifts off the throttle or brakes, thus speeding up response times when cornering. Compared to, for example, the current Audi electric turbo in the V6 diesel S4 or S6, which spins up to 50,000rpm, the Mercedes-AMG electric turbo reaches 170,000rpm.
"We have clearly defined our goals for an electrified future. In order to reach them, we are relying on discrete and highly innovative components as well as assemblies. With this move we are strategically supplementing our modular technology and tailoring it to our performance requirements. In a first step this includes the electrified turbocharger - an example of the transfer of Formula One technology to the road, something with which we will take turbocharged combustion engines to a previously unattainable level of agility", explains Tobias Moers, Chairman of the Board of Management of Mercedes-AMG.