|
Autosport magazine features NRE (Nippon Race Engine). <Part.2, Lexus>
*Lexus (RI4AG)
-NRE's season mileage is 7,000 km in total 8 rounds.
-The initial firing of RI4AG was in March 2013 and shakedown in July.
-The throttle valve was single at the beginning of development but changed to a multi-throttle valve at the beginning of the season.
(Class one regulations prohibit multi-throttle valve. Plus alpha regulations allows it.)
-The development theme for 2014 was the effective use of turbochargers and fuel restrictors.
-Lexus experimented with various piston crown surface shapes.
-Lexus also tried to change the cam's working angle several times.
-The exhaust manifold was changed from 4-1 exhaust to 4-2-1 exhaust.
-The development theme for 2015 was to optimize the intake and exhaust systems and the compression ratio.
-Lean air-fuel ratio was taken up as a development item in 2015.
-The development theme for 2016 and 2017 was to respond to high combustion pressure.
-In 2016 spec, the shape of around the spark plug area and the squish area have been changed.
-Lexus changed the chassis to LC500 in 2017, significantly improving cooling performance.
As a result, Lexus improved engine performance by 5% due to lower engine intake temperature.
-LC500 has improved maintainability and the engine replacement time (3 hours) is shorter than RC F (5-6 hours).
-Improvement of turbo lag using anti-lag control was also an important theme in 2017.
-The development theme for 2018 was to prevent damage to parts due to higher combustion pressure. (TRD has not confirmed it, but it appears that pre chamber ignition was introduced in 2018?)
|