Multiple features make GrimmSpeed hiflow crosspipes a “must have” for Subaru enthusiasts. Despite their sporty presence, the stock packages for WRX and STI models were not assembled for maximized results. A GrimmSpeed hiflow crosspipe changes that. The OEM tubing is thin and underwhelming, constantly robbing your car of horsepower. With just one easy replacement, you can experience a greater threshold of performance to reach the next level. GrimmSpeed hiflow crosspipes offer a thicker, stronger, and more efficient answer to the factory pipe. You can find them for the Impreza (WRX, STI), Legacy (GT), and Forester (XT).
Right from the start, Subaru custom crosspipes are extremely sturdy. GrimmSpeed employs 304 stainless steel for the entire manufacturing process, including the 1/2” thick flanges. The walls are crafted with 14 gauges of depth. The goal of Subaru custom crosspipes is to present a stronger and more reliable tube than the stock part. This is also evident in the flex joint. Made of 1.92” steel, the flex joints not only demonstrate uncommon resilience, but their location plays a role, as well. GrimmSpeed designed Subaru custom crosspipes with the flex joint placed away from the bend. The joint’s placement prevents both rattling and risk of damage.
Inexperienced drivers may wonder what improvement Subaru custom crosspipes initiate. The original part is narrow, which means that it makes it difficult for exhaust to flow through adequately. Grimmspeed crosspipes are wider and provide a concise route for airflow to reach from the cylinders to the manifold collector. This process speeds up the turbo, helping increase horsepower. The actual amount of HP gained with a Grimmspeed crosspipe is dependent on several variables. By itself, you can expect to see up to about 8 extra horses. However, if mated with other exhaust upgrades, a Grimmspeed crosspipe can produce between 12-16 HP.
Due to the emissions guidelines in numerous jurisdictions, some Subaru performance parts are intended for off-road use only. Most commonly, upgrades such as a WRX high flow cross pipe are used by competitive racecar owners and demonstration drivers. It is suggested to refer to your state motor vehicle commission to confirm if the part is “street legal.” If it is not, the aftermarket exhaust pipe can be switched out when you are not at a track or course.