Variable drive specialist Torotrak has formed a 50-50 joint venture with centrifugal supercharger firm Rotrex, called Rotrak, to develop affordable engine downsizing technologies.
"Rotrex is the world leader in centrifugal supercharger technology and has for many years delivered their compact, efficient and near-silent products to some of the leading companies in the world," says Torotrak chief executive Dick Elsy.
"Adding Torotrak's scalable variable speed traction drive will overcome many of the compromises that affect current pressure-charging systems," he continues, adding that, as engines get smaller, the challenge becomes one of boosting performance across the entire speed-range to provide larger engine responsiveness.
Rotrex managing director Lars Kristiansen makes the point that conventional turbochargers struggle at low speed, particularly in these smaller engines. Better low-speed boost can be achieved but it is complex and costly, he says.
Supercharging is the main alternative, but the fixed ratio between engine and supercharger speeds means that if boost is optimised for low-end response, then energy is wasted at higher engine revs.
"Torotrak and Rotrex are ideally positioned for the development of variable drive supercharging systems," says Kristiansen. "For some time we have been looking for a scalable, efficient and durable technology to provide a variable drive capability for our centrifugal compressors and our studies have confirmed that Torotrak is the clear leader in this field."
