How an engine pulls as the revs rise depends partly on the way its valves open. The camshafts of the Mazda MX5 NC (2005 - 2015) determine valve lift and opening duration. A different camshaft can change the character of the engine, but needs to work with the intake, exhaust and engine management. This is why complete BBR packages are listed here, as well as under engine tuning. Their contents vary by package and engine version.
