It's called upping the horsepower and shaving weight.
Detroit is over and now it’s time for Geneva. We’re receiving more news everyday about what to expect from the Swiss show this March, and now we’ve received confirmation from McLaren that it has something special planned. Straight to the point: an even more potent 650S, rumored to be called the 675 LT. McLaren has described its upcoming new supercar as being "more powerful and track-focused" than the 650S. Power will once again come courtesy of the twin-turbo 3.8-liter V8, this time making at least 666 hp, up from the 650S's 641 hp.
Performance times will also be faster and top speed is said to be over 207 mph. Weight should be down by at least 220 pounds. McLaren has also released a teaser spy shot image of its new model. Notice the slight changes in the front bumper and a new low-mounted side air intake. What’s more, the prototype’s shape echoes that of the 1997 F1 GTR "Long Tail," a Le Mans 24 Hour endurance racer. Production will likely be limited to about 250 examples, but we’ll know more in the coming weeks.