Following two years of on-track struggles with a diesel platform, Mazda will debut a new 2.0-liter turbo-4 gas engine in the IMSA WeatherTech SportsCar Championship this season.
“We gained immense knowledge from three years of racing a stock-block diesel engine. That knowledge will improve the next generation of Mazda diesel engines,” says John Doonan, director of Mazda Motorsports in North America. “But, with the impending rules changes in 2017 [which will not allow a diesel-fueled option], a purpose-built racing engine was our best choice to reach our long-term goals and contend for race wins and championships.”
Designated as the MZ-2.0T, the engine was developed by Mazda and Advanced Engine Research (AER) and is based off the MZR-R engine built in 2006 for sportscar racing. The MZR-R currently powers all the Indy Lights cars.
“After extensive testing, the MZ-2.0T is not only very fast, but reliable as well,” adds Noonan. “There was no off-season for this team, as they’ve worked incredibly hard to prepare for the season. Mazda loves to race, and we couldn’t be more optimistic about the prospect of this engine and our team.”
Mazda has yet to release a photo of the new engine, but previous shots of the MZR-R will give an indication of the architecture. We know the MZR-R utilized a single Garrett TR30R turbo and was rated at 500-plus horsepower when saddled with a 42mm air restrictor. The MZR-R features chain-driven camshafts and sports a 90mm bore and 78.4mm stroke.
Details on the MZ-2.0T that Mazda has released include a rating of 570 horsepower and a redline of 9,000 rpm. The direct-injection system feature multi-hole, spray-guided injectors and a fuel rail pressure of more than 1,500 psi. The Garrett turbo is mounted to a 4-2-1 exhaust manifold and will provide just under 38 pounds of boost to the custom carbon fiber intake manifold. Compression ratio is 13.5:1.
The MZ-2.0T replaces the 2.2-liter, compound-turbo SkyActiv-D diesel engines used for the past two years in the Mazda prototypes built by SpeedSource Race Engineering and Multimatic Engineering. EngineLabs offered an in-depth look at these engines two years ago. Team officials are now optimistic about the move to a gas powerplant.
“The drivability of the engine is incredible. The first thing you notice is how smooth the power is delivered in every gear through the rpm range. There is great low-end torque with zero turbo-lag, which is very impressive, ” says Jonathan Bomarito, driver for one of the cars. “All race tracks are different and the gearing is never perfect for every corner, so having an engine where you can short-shift or stretch a gear longer is very important. The MZ-2.0T does this easily.”
“This engine has transformed everything for us. Obviously, it’s more powerful so we’re going faster. Once you go faster, the aerodynamics work very differently – we have much more downforce – and the chassis works better. It’s not just straightaway speed, the engine has improved every aspect of our overall performance,” adds Marcus Shen, chief engineer of the Mazda prototype team.