Video: Mazda Skyactiv-D Diesel Shows off Compound Turbos on Dyno

Mazda’s Skyactiv-D racing program has struggled running its first two races in the new Grand Am GX class, which was launched this year to promote new and experimental technology. The Mazda6 racecars are powered by a 4-cylinder turbo diesels, marking the first time an oil-burner raced in the Rolex 24 Hours of Daytona, which opened the Grand Am season. Mazda finished well behind the Porsches in that race, then ran 35th and 32nd at the next event in Austin.

Not much is known about the new diesel program, but there is a quick dyno video that shows off the compound turbo setup very clearly — although it’s likely the packaging is a little tighter in the Mazda6 body. Mazda race notes reveal the low-pressure side is a Garrett GTR3776R turbo while the high-pressure side sports a GTR2560R unit. Exact numbers weren’t disclosed, but the class is designed for engines producing around 400 horsepower. Mazda says the Skyactiv-D pulls over 445 lb-ft of torque at 3,600 rpm. Max boost is reported to be 70 psi.

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Other specs that have been released include 2.2-liter with a 86mm bore and 94.3mm stroke, and the common-rail direct-injection system is controlled with a Bosch ECU. Mazda says more than 250 part numbers from the production engine are used in the race version. The engine must also carry over the stock 14:1 compression ratio.

Mazda has promised a technical program on the engine next month, so hopefully we’ll be allowed to dive a little deeper into this emerging race technology.