Andy Palmer (not to be confused with the man of the same name who oversees Aston Martin), is McLaren's vehicle line director. In the accompanying video, he goes over some of the basics of the car, then hands it over to Jonny Swinhoe, McLaren Program Manager. Both men highlight some of the major differences between the Senna GTR and the road car.
Yes, the Senna GTR is a track-only car. It also wasn't homologated for any particular race series. That allowed McLaren to build a car almost totally free of FIA restrictions and government regulations. Foremost, the body is slightly wider due to its larger racing slicks. The added width gives an already angry car and even angrier stance.
McLaren Senna GTR
The car features a lot of changes to its aerodynamics package. The front splitter is revised and canards are added along the sides of the bumper, the underside of the car is reworked to improve aero efficiency, and the rear wing is pulled farther back, which allows the airflow coming off the wing to interact with airflow from the diffuser. Translation: there's a lot of downforce here, far more than the road-legal Senna. While the standard car creates 1,700 pounds of downforce, the Senna GTR makes 2,205 pounds of downforce at 155 mph.
McLaren Senna GTR
The cockpit changes for track duty, too. Instead of the fold-away cluster, it has race-spec gauges and a steering wheel based on a GT3 design. The integrated roll cage was a must, of course. From inside, the 4.0-liter twin-turbo V-8 probably sounds even wilder as it produces 814 horsepower. That's up from 789 hp in the standard Senna, for anyone not keeping score at home.
The Senna GTR seen here was the first prototype car, but the first few cars should already be in customer hands. Only 75 will be built, each for about $1.43 million. Listen for the reworked exhaust note at the end of the video and tell us that alone isn't worth the price of admission.