Why does 2015 Subaru WRX STI NBR run a 2.0-liter engine?

The all-new 2015 Subaru WRX STI NBR race car will be running the Subaru Boxer F4 2.0-liter turbocharged engine that comes in the 2015 WRX. Why isn’t Subaru running the 2.5-liter that comes in the new 2015 WRX STI? The 2015 Subaru WRX STI Nurburgring 24-hour race car runs in the SP3T class for turbocharged engines displacing 1.75 to 2.0 liters. Is it the best engine?

The 24-hour Nurburgring will take place from June 19-22 in Germany in which STI will participate for the 7th time in a row. Subaru will bring a new car this year, the 2015 WRX STI. All stages of work on the car from the design were carried out in close cooperation with the parent company Fuji Heavy Industries (FHI). Last year the 2014 WRX STI NBR car finished second in its class, and STI expects a third consecutive victory in its class since 2012.

Subaru will be in the SP3T class, for turbocharged engines displacing 1.75 to 2.0 liters, and will run in a competitive class with racing versions of cars from Audi, Volkswagen and Seat. The new WRX STI should be a good performer with the 2.0-liter F4 powerplant. Many believe its a better engine than the production 2.5-liter the new STI comes with.

The new 2015 WRX 2.0-liter engine uses a combination of direct injection, high compression (10.6:1), Subaru Dual Active Valve Control System (D-AVCS), a twin-scroll turbocharger and an intercooler to get improved performance over the similar Forester XT version. The WRX STI NBR version will use different cams and higher-rate valve springs and other enhancements to enhance the performance envelope. The production WRX 2.0-liter gets a broader torque curve and peaks at 258 lb.-ft. over a 2,000-5,200 rpm engine speed range.

STI will have two experienced drivers, Hisahiro Yoshida and Kota Sasaki, and they plan to add two more drivers from Europe for the 24-hour endurance race. In addition, working in the pit area, will be top Subaru techs from Subaru service departments located throughout Japan. It's an honor for these top Subaru mechanics to be in the pits helping the STI team.

Subaru has unveiled the 2015 STI in Geneva and now the car is headed for Germany, where it will take part in the race VLN qualifying runs. Final adjustments will be made to the car just before it participates in the June 24-hour race.

Tomohiko Ikeda, Corporate Executive Vice President Chief General Manager, Subaru Global Marketing Division Fuji Heavy Industries Ltd was at the Subaru press conference at the 84th Geneva International Motor Show. He said Subaru has reinforced collaboration with its motor sports subsidiary, Subaru Tecnica International, to create an innovative and more competitive race car based on the new 2015 Subaru WRX STI production model.

The Nurburgring 24-Hour Race will be extremely demanding on the new 2015 WRX STI NBR car, and the new 2.0-liter engine should prove to be a good powerplant. Stay tuned to Toque News for the Nurburgring 24-hour race results.

Other 2015 Subaru WRX STI NBR stories of interest.

• 2015 Subaru WRX STI has deep connection to NBR race car
• 2015 Subaru WRX STI NBR runs “Corkscrew” at Laguna Seca