A typical 40R puts out about, what, 60lb/min of air at the top of its max efficiency range? A typical conversion of HP -> lb/min is 9-10:1. So that is ~570hp.
Using RC Engineering's handy-dandy injector sizing utility, and using it recommended settings, they would need to run the injectors at 100% duty cycle and 52psi.
Now let's add the supercharger into the equation...
Yes, they probably need more injector, or not use such a large turbo.