本帖最後由 prelude318is 於 2010-1-2 18:44 編輯
i have 08 Civic Si K20Z3 motor.. and tell you what.. header makes the most gain out of the I/H/E mod on K-series... either with or without high flow cat... the exhaust is restrictive because of the stupid stock header runners are too short, especially at high rpm range...given the way Honda installed the motor this way( intake at the front, exhaust to the firewall), the exhaust manifold collector and the cat is very close to the head, therefore short exhaust runner........ ... the cat is restrictive but for sure not as restrictive as the header |