Quote Originally Posted by Mirek View Post

The acceleration of the turbo depends a lot on its size. When talking about situation without ALS the smaller turbos have rather rapid response and give good pressure at low engine rpm but don't bring anything for high engine rpm because the turbo gets beyond its safe rotation speed. These turbos are typical for modern stock engines. They add torque at low rpm but don't add much to the peak power.

The larger turbos which You need for racing give more pressure at high engine rpm but are slow to accelerate from iddle state (due to larger inertia of the compressor and turbine) and also the exhaust gasses at low engine rpm don't have enough energy to propel them, i.e. such turbos don't bring much at low rpm and need ALS or electric motor to speed up their response.
Where do you classify the turbo of the wrcars?i suppose to relatively small ones since they can switch off the the als if it is needed.