ISR Performance Pro Series Coilover Kit Mazda RX7 FC3S Wheel Offset_25mm After comparing many different muffler

After comparing many different muffler sizes and designs

Other K20/K24 performance builds and swaps

The body and all internal components are CNC-machined from 6061 aluminum alloy

but the optional 3in adapter simply bolts on and removes the bottle neck if you plan to use a 3in downpipe

and even lost over time

ISR Performance Pro Series Coilover Kit Mazda RX7 FC3S Wheel Offset_25mm After comparing many different mufflerPart #: IS PRO FC3S After Years of Success with the Basic Coilovers ISR Performance has released a higher end line of coilovers providing better dampening control and overall performance. These are a great coilovers for the street and track use. Provides a comfortable ride while improving handling. Features: 32 Way Adjustable Dampening Mono Tube Design Spring Rate: 8K 6K Front Pillowball Upper Camber mounts. ** ISR Pro Coilovers Utilize High End