Craig Balis, Honeywell’s chief technology officer for transportation system business, says electrification is coming to turbochargers in regular passenger cars. These e-turbos won’t just boost engine performance, they will also generate electricity, lightening the load on the alternator and helping to improve fuel economy. Balis spoke with Staff Reporter Richard Truett.
Q: There is some debate about how to refer to electrically driven boosting devices. Are they e-turbos or electric superchargers?
A: When you hear “electric supercharger,” that is a motor driving a compressor, and that is added to an engine that’s already turbocharged. So it is an additional device. With an electric turbocharger, what we mean is, instead of having a separate motor on a separate device, we put the motor on the shaft turbocharger.
Is Honeywell active in both types?
Yes, we are. I can give you two examples we have on the road and track today. In Formula One, Ferrari is racing with electric turbochargers made by Honeywell. So it’s a motor on the shaft of the turbo. The Honda Clarity fuel cell vehicle is boosted by an electric supercharger that is also made by Honeywell.
In addition to the electric motor eliminating turbo lag, what other advantages does it offer?
The e-turbo is still using exhaust gas, but it is using the electric motor to spool up the turbo faster. When you have excess exhaust gas, you can run the motor in generating mode. You can extract the energy out of that exhaust gas, create electricity and feed it back into the vehicle network. That’s what we call an e-turbo.
Would an e-charger have fewer technical challenges than a traditional exhaust gas-driven turbo, since it would not be subjected to the same level of heat?
That’s why people have gravitated to this concept. You are running at lower speeds. A typical turbocharger will run at between 200,000 and 300,000 rpm, while an electric turbocharger can run at 100,000 rpm. So it’s more challenging to make an electric turbo. But it brings other advantages — and fewer parts, because you’re not adding an extra package to the engine. And then you get the additional functionality of being able to generate electricity.