Mazda’s Racing Diesel

By Christopher A. Sawyer

Mazda is the first car maker to announce its participation in Grand-Am’s new GX racing class in 2013. The division features advanced/clean powertrain and fuel technologies, though that description is both broad and vague; it includes turbocharged gasoline engines, diesels, hybrids and more. Mazda’s announcement also signals its entry into the diesel market in North America.

According to Grand-Am President and CEO Ed Bennett: “A number of OEMs have expressed their desire to field cars that wouldn't fit within our current two-class structure, so it makes good sense for us to find a way to accommodate those desires.” He also said the series added the class as a way to accommodate automakers interested in the series, but not willing to compete in either the DP or GT classes. However, though there have been suggestions that Porsche and others have agreed to run in the GX series, Mazda is the only firm commitment thus far.

Dyno testing of the racing Skyactiv-D 2.2-liter diesel is currently underway, and on-track testing will take place in late 2012 in anticipation of the series’ debut at the 2013 Daytona 24 Hours. This program will replace Mazda’s RX-8 racing program, though the company will continue to support teams that stick with this car and pay contingency money to teams racing the RX-8 in 2013. It is unlikely this program will continue beyond next year.

SpeedSource Engineering, Mazda Motor Corporation and Mazda North American Operations are jointly developing the new engine. Though based around a production block, heads and common rail injectors, the valves, pistons, connecting rods and oiling system have been replaced with racing-specific components. Grand-Am has set an initial goal of 400 hp for this category, though this number could rise as the final rules package is set. Plus, given the sanctioning body’s desire for close racing, competitors can expect Grand-Am to level the field should any competitor get too big of an advantage.

Mazda will provide the engines to teams, but is not running a factory effort and has yet to name which vehicles will race with the Skyactiv-D race engine. It also has not stated which of its current offerings will be fitted with this powerplant in production, though the engine will debut in the home market CX-5 small crossover next Spring. Because it is a low compression ratio engine (it runs at relatively low 14:1 to keep NOx emissions in check), the block and head can be make of aluminum, which reduces weight. However, this does not harm its output. The Skyactiv-D reportedly produces 310 lb-ft of torque, and easily could find its way into vehicles like the CX-9 and the next-generation Mazda6