The stock over pipe on the FR-S and the BRZ is not only too narrow but it also has flattened sections which severely limit the performance gains from adding go fast parts such as an exhaust or an aftermarket manifold, like the Expreme Tomei Manifold.
The new Tomei Expreme Over Pipe however retains a continuos 60.5mm design, eliminating any flat spots on the pipe itself. The pipe also has additional welded beads inside of the unit to increase rigidity and durability. If you are already rocking the Tomei exhaust, complement it with this over and perhaps the Tomei manifold to have a substantially superior exhaust system over stock!