Installing a new Perrin uppipe is the preferred method of ending exhaust restriction for Subaru car owners. The reason is because coming from the OEM unit, there is a high amount of backed up airflow that struggles to get through. This holds up performance. A Perrin Subaru uppipe is designed to open up the airway, resulting in an increase in flow velocity that allows for more power to be unlocked. This is one of the most common upgrades for Impreza drivers due to its immediate effect. The difference a Perrin Subaru uppipe makes is evident as soon as it is bolted in place.
Turbocharged cars respond to higher exhaust flow. When fed from the headers, a Perrin uppipe is able to distribute air in a more liberated fashion. This helps turbo spooling increase. Your Subaru exhaust system is no longer being held hostage at the manifold. Air coming through is denser and able to be moved through without being obstructed by narrow tubing. Perrin uppipes feature flanges that are engineered to exactly match the manifold outlet and turbo inlet of your car. This is for both fitment and efficiency. The interior diameter of Perrin uppipes is extra wide so that the exhaust released from the manifold does not hit a snag on its way out.
Stainless steel highlights this part. All Perrin uppipes are crafted from stainless steel. The tubing is comprised of 321 steel. After being initially rendered, Impreza custom up pipes are mandrel-bent, which is a digital process that mechanically bends the pipe to a desired angle. This aids in sustaining strength at the bends, as well. The flanges on each side of an Impreza custom up pipe are fashioned from T-304 stainless steel and CNC-machined to 1/2” in thickness. The company makes their flanges thick so there are no connectivity issues to OEM parts or a full Perrin performance exhaust.
Installation is not too difficult, although prior experience is recommended. Impreza custom up pipes come equipped with all necessary hardware as well as step-by-step instructions. It is a bolt-on part. Most of the installation centers around the removal of OEM bolts from the turbo and intercooler before the big tube up pipe can be set in place.