John Cooper Works did a good job of providing a factory approved performance upgrade, unfortunatly they didn't go far enough. Based on how many requests we have recieved on upgrading beyond the JCW package we have developed 2 upgrade paths for current JCW owners seeking more power. The Madness Stage 2 JCW upgrade consists of the following products: Madness Cold Air Intake. Feed that supercharger the air it deserves! Madness Cowl Mod. More than double your cold air feed to the supercharger. Works in conjuction with the Madness Cold Air Intake Madness Big Bore 63mm Throttle Body, significant increase in throttle responce and elimination of factory airflow bottleneck Schrick Cooper S Cam, why JCW left this out is anyones guess. The Cam is an integral part of any cylinder head modification allowing you to take full advantage of the high performance head you already have. Madness Water to Air Intercooler. Significantly reduces air charge temperatures. Cooler air is denser air. Madness Header. JCW only went half way with their exhaust system. The missing link is the Madness Header which eliminates the restrictive factory unit. Estimated 35-40hp gain •••••This package requires a $200 core charge not included in the list price. After installing the new throttle body, send your original one back to us in good condition and we will credit you the core cost.••••• No core return available for INTERNATIONAL ORDERS, core charge will be automatically added to the final cost.