For serious racers, a GrimmSpeed Subaru crosspipe represents a way to glean more power from the exhaust system. Keeping air flowing freely is not easy with the OEM setup, as it was not designed for consistent high performance. GrimmSpeed Subaru crosspipes are all about providing a roomier route for exhaust to flow through. The result is a boost in horsepower that sustains, whether on the track or at the strip. Other steel racing parts may help give your car added boost, but without a GrimmSpeed Subaru crosspipe the package is not complete.
Off the assembly line, Subaru turbo models do not have an exhaust manifold pipe meant for custom application. Instead, the part is narrow and unimpressive. Because of this, exhaust is constantly choked in place. Replacing it with a high flow crosspipe unlocks this restriction. Featuring an inside diameter of 1.92”, airflow is generously increased to the cylinders so that the turbo can answer back more effectively. High flow crosspipes also have a triple layer flex joint located in the center. This helps with heat expansion when you are opening up the throttle over distance, maintaining proper exhaust flow even as the RPMs ascend.
Throwing a ceramic coating on your high flow crosspipe can add to further results. The reason is simple. What the ceramic coating does is enact a protective layer over the surface of the high flow crosspipe. When pipes get hot, the heat radiates and escapes. A layer of ceramic-infused paint keeps the heat inside where it should be. With better heat management, aftermarket performance cross pipes help exhaust flow move around faster.
GrimmSpeed uses 304 stainless steel to ensure enduring toughness. The walls of each aftermarket performance cross pipe measure in at 14 gauge steel thickness. By comparison, many competitors employ lesser 17 gauge steel, which is noticeably thinner in construction. If you plan on driving in competitive situations, a thicker aftermarket performance cross pipe will hold up longer.
Actual horsepower numbers may vary. Some Impreza owners have claimed an increase between 12 and 15 HP when mated with other WRX exhaust parts. Without any other modifications, a jump of up to 7 extra horses can be expected.