Custom straight air intake Brand Custom Website - Part number - To improve the airflow towards the turbo I made a 80 mm outer diameter (OD) aluminium straight intake. For a stock ST185 setup you need one with connections for the Positive Crankcase Ventilation (PCV) or oil catch tank and one for the Idle Speed Control (ISC) valve. Samco 70 > 80 mm inner diameter (ID) reducer to fit the stock CT26 turbo - 80 mm OD straight intake - 80 mm ID coupler to fit the CS/GrpA Rallye/RC airflow meter (AFM) AFM adapter To fit the A'PEXi Power Intake to the larger CS/GrpA Rallye/RC AFM I also made an AFM adapter. Due to the larger inlet, the AFM has a different bolt pattern compared to the normal ST185. Related links A'PEXi Power Intake CS/GrpA Rallye/RC AFM bolt pattern Modifications - Engine Top