A couple of years back I purchased MX-5 NC to participate in club motorsport. After a year of racing, during which time the suspension, brakes, wheels, tyres, and exhaust had the usual treatment I was starting to think about more power. I wasn’t keen on turbo charging so the different supercharger options on the market were investigated.
The conclusion was that roots-type positive displacement superchargers were a good choice for autocross style motorsport were full power is required from low rpms to pull out of tight corners, but weren’t great in the higher rpm range. Whereas the centrifugal superchargers have a better adiabatic (thermal) efficiency and are better for track use when the engine speed can be kept above 4000 rpm (as the boost pressure increase as the square of the engine speed).
As the vehicle is used for a wide variety of motorsport why not have the best of both worlds, boost down low and up high with good adiabatic efficiency. Plus the ability to adjust boost level and delivery to match the course and event.
