CSF Twin Intercooler Set 2013-2019 Porsche 911 Turbo (991)/Turbo S (991.1/991.2)CSF Cooling is proud to announce the official public release of its Porsche 991 Turbo & Turbo S high performance intercoolers for both 991. 1 & 991. 2 models. Since the intercoolers made their official world debut at the 2017 SEMA show, a unique sales decision was made to only release these intercoolers (for a period of 1 year) to a select group of the worlds most highly regarded Porsche motorsport ECU tuners and vehicle builders. Over the past year,