ISR Performance Exhaust Silencer 4 inch | IS-UNIS-4 vendor_Humble Rumble ACL's high quality rod bearings

ACL's high quality rod bearings will prevent fatigue

By using a 57% larger intercooler core with streamlined intercooler piping

2008-2021 Subaru STI (15-17 STI W/OEM SOUND TUBE DELETE)**

Each Alpha radiator uses a dual core design with high flowing fins to maximize performance

The COBB Tuning SF Intake removes a pre-turbo restriction in the stock intake system

ISR Performance Exhaust Silencer 4 inch | IS-UNIS-4 vendor_Humble Rumble ACL's high quality rod bearingsISR Performance Universal Exhaust Silencers 3" or 4" Can be used on any Exhaust system with 3" or 4" tips. Exhaust needs to be drilled to accommodate the Silencer set screw hole. Set Screw not included This item is non application specific. Please verify compatibility before purchase. May require some modification for proper installation. Note: ISR orders might take a day of processing. If you need it sooner, contact us directly.