That the MP4-12C became the 12C and now the 650S in just three years indicates two things.
First, that McLaren is a road car company still finding its feet, and second, that it’s a road car company capable of making changes at race-team speed.
Visually, the distinction between 12C and 650S is relatively broad. The new headlights are the biggest tell between the two models and are P1-inspired. But it’s the changes that are less visually obvious that are the most significant.
The M383T-designated twin-turbocharged V8 engine in the 650S is ostensibly the same one we know well from all of McLaren’s cars. The Woking firm takes great pride in the fact that, depending on where you find it, the engine will make anything from 532bhp (or thereabouts, in the forthcoming P13) all the way to 737bhp in the P1.
Here in the 650S it makes 641bhp. The hardware differs from that used in the 617bhp 12C thanks to new pistons and a redesigned cylinder head. There are also new exhaust valves and the cooling circuits have been redesigned to better deal with the inevitable extra heat that comes with such a power increase.
Camshaft timings are different, too. These are said to improve both economy and throttle response, while a new exhaust system is lighter than before. McLaren’s intention was to improve the perceived response of the engine. As such, torque now builds from 3000rpm to 7000rpm rather than plateauing, so the more revs you have, the faster it feels.
