CSF Radiators Audi RS6/RS7 Intercooler Set (C8)CSF Core design Rolled Tube & Billet End Tanks The CSF intercooler for the C8 RS6 & RS7 is a larger, more efficient intercooler for significantly improved cooling power. PWRs rolled tube cores are optimised in PWRs in house wind tunnel, through this process PWR select the optimum stack height and multi louvred fin design for both the ambient and pressure sides for optimum balance between cooling power and pressure drop. OE CSF Number of tubes 22 45