FC1 Civic Si build order: tires, then a Hondata FlashPro tune, then charge cooling, then a rear sway bar and motor mount insert. The L15B7 doesn't need a cat-back to feel fast — it needs grip, a map, and cold air temps. Order beats parts. #ThreePieceUS #CivicSi #FC1 #L15B7 #Hondata #HondaBuild #cars #wheels