CSF Porsche 911 Turbo (991)/Turbo S (991.1/991.2) Twin Intercooler SetCSF's Porsche 991 Turbo intercoolers have been race tested, logged, and fully validated by some of the world's best Porsche tuners. These intercoolers have been regarded as the "Go To" option for the best performance and value available in the performance aftermarket. From first glance the increase in width from the OEM's 80mm core to the CSF's 115mm width is very apparent. Critical for vehicles running performance tunes with bolt on modifications.