RCZ is basically correct....... Intercoolers are absolutely necessary to cool the Charge air which is heated from compression. A nicely balanced system will handle pressure drop, temps and flow nicely and make more power. The lower you can keep the temps at the manifold, the greater timing advance and consequent power is developed. It's is widely known that cooler air makes more power..Most of that (Not factoring in Boost), when measured as IAT's is coming from timing advance..Regardless, FI or not, cooler is always better...
My last Audi with a well balanced, intercooled turbo system at 23 PSI:
