McLaren begins dynamics testing of Senna GTR
aerobd.news : The Senna GTR is an even more extreme version of the road-legal McLaren Senna currently being built by McLaren, being a track-only, left-hand-drive only variant. The development team begins testing prototypes this month, but any mules spotted will not show the final shape, as they will initially be fitted with modified bodywork from the Senna road car. Instead the final carbon fiber body will have wider fenders, a larger front splitter, and a larger rear diffuser and repositioned active rear wing, the latter two elements combining to improve aero-efficiency by ‘coupling’ the wing to the airflow from the diffuser, creating greater downforce at lower speeds.
The optimized aerodynamic performance in yaw is intended to improve cornering stability, while the reduction in pitch sensitivity leads to greater braking stability. As the Senna GTR is not a homologated race car, it retains the active aerodynamics systems of the road-legal car, which is a major enabler in one of its headline figures: 1,000kg of downforce. McLaren has also revealed that the car will be based around a chassis with a wider track front and rear than the road car. The GTR will also have a conventional double-wishbone suspension, with the geometry, springs, dampers and anti-roll bars developed from the system engineered for McLaren’s GT3 customer racing program. Other GTR features include center-lock wheels, Pirelli slick race tires, and the race-derived braking system from the Senna road car, which is projected to deliver 20% greater maximum deceleration, with resulting forces in excess of 3g.
A final vehicle weight is still to be declared, but McLaren has confirmed the GTR will weigh less than the road-going Senna. In combination with the 825PS output of the 4.0-liter twin-turbocharged V8 engine – an increase of 25PS over the road-legal Senna – this will certainly see the power-to-weight ratio exceed that of the road car, complemented by torque of up to 800Nm. While the GTR loses some comfort features of the Senna in the pursuit of minimal weight, including airbags and infotainment, the air-conditioning system is retained, as is the rear collision avoidance system. If this sounds appealing, the bad news is that only 75 GTRs will be available, they cost £1.1 million plus taxes each, and they are all allocated, with deliveries expected to begin from September 2019 when production of the road-legal McLaren Senna is complete.
source : Vehicle Dynamics International