Perrin Equal Length HeaderIncrease HP and TQ on your 2022 2025 WRX with a PERRIN Equal Length Header. With larger primary and secondary tubes, you can expect 5WHP on Stage 1 cars and far more on 350+ WHP cars without sacrificing turbo response. Power Testing on an aggressive Stage 1 Tuned 2022 WRX with typical bolt ons installed adds 5 10WHP at the upper RPMS and even more on cars pushing past 350WHP! Racecar Quality Expansion Joints PERRIN headers use high quality expansion