Lexus will be demonstrating the Lexus RC F at the Goodwood Festival of Speed happening later this week, which would be the first time the public will be seeing the RC F in action. It will both be doing demo runs on the Goodwood hill climb as well as compete in the climb.
Powering the RC F will be a revised 5.0 litre V8, upgraded with new features from the one found in the previous IS F. Output is 450 horsepower and 520 Nm of torque, driving the rear wheels through an eight-speed Sports Direct Shift gearbox. The RC F is also equipped with a torque vectoring differential, which allows shifting drive between the rear left and right wheels as needed.
Now you might be thinking that Lexus is lagging behind the competition, still using a large normally aspirated engine compared to competitors who have all gone with reduced displacement V8 engines. The BMW M3 uses a turbocharged 3.0 litre straight-six while the upcoming C 63 AMG is expected to use a turbocharged 4.0 litre V8.
But the RC F’s V8 has a bag of tricks of its own, which includes something we’ve never heard of before – the ability to switch between the Otto cycle and Atkinson cycle.
Most car engines use the Otto cycle. The Atkinson cycle is usually more efficient because of its greater thermal efficiency, but comes at the expense of power to displacement ratio, so they’re normally only used in hybrid engines. The only car to use an non-hybrid Atkinson cycle engine that we know of at the moment is Mazda’s SkyActiv engine.
Basically the ability to run on both Otto and Atkinson cycles give the Lexus engine the ability to produce lots of power when the driver demands it, but run fuel efficiently while the owner isn’t chasing M3s as well.
How does the engine achieve this? Lexus has used electric cam phasing which allows for far greater flexibility compared to traditionally hydraulic-powered variable cam timing devices. The electric cam phasing solenoids hold the intake valves open longer to lengthen the power stroke to achieve an Atkinson cycle during light loads, and revert back to normal valve timing during heavy load.
We look forward to seeing what the RC F can do at Goodwood. Hopefully Lexus will be producing a video.