AMS Performance Toyota GR Supra A90 Street Downpipe W/ GESI Catalytic ConverterThe 4. 5 full mandrel bent downpipe is the best performing and most durable on the market. Power comes in earlier and turbo spool up is significantly improved. The long gradual transitions within the mandrel bent pipe allows exhaust gasses to maintain velocity without a buildup of back pressure inside of the system. We were able to design a superior product because of our superior engineering. The catalyst has a newly formulated substrate with a