Autosport web reports GT500 development frontline <Nissan>.
https://www.as-web.jp/supergt/693413?all
2020 was the year when the development freeze on cast parts such as cylinder heads, engine blocks, oil pans and crankshafts was lifted.
NISMO changed the engine name to NR20B last year.
Surprisingly, NISMO changed the engine name to NR4S21 again this year.
Development of cast parts has been frozen in 2021.
However, cutting machining for cast parts is possible and the engine port shape can be changed.
You can also change the piston, connecting rod, and camshaft (this can also be changed with the second fresh engine).
Yuzo Ishikawa (NISMO powertrain development) says that NISMO decided to change the name because it evolved the engine, although the origin of the name is left to the imagination.
In short, the engine performance of the NR4S21 is improving.
He says that anyway, it's all about improving combustion. Review ignition, review compression, review air-fuel mixture. All of these are connected, so if you change this, you must change that too. they are fixing it while repeating it
Regarding the engine, the mileage per test time increased 1.7 times last year despite the test restrictions because the trouble was suppressed.
Motohiro Matsuura (NISMO general director) says that compared to GR Supra, the amount of drag caused by the base vehicle of GTR is disadvantageous.