Sorry for the late reply. On a car like this (designed for track use only), there's no real need for an emergency brake as most circuits are pretty flat where the cars are stationary (under normal circumstances). Having no E-brake on the car helps to reduce the weight and simplifies the braking system.
And also avoids the possibility that you'll inadvertently put the handbrake on after a track run and heat soak the rear brakes, with potentially serious consequences when you go back on track. No one with any sense would use a handbrake on a race car anyway- at least not when using the car for its intended purpose.
