Looking for an easy way to get that turbo whoosh on your R55, R56, R57 Cooper S? Forge's Blow-Off Adapter Plate may just be what you're looking for! The Forge Blow-Off Adapter Plate goes in between the turbo and the stock diverter valve, and lets the air vent directly to atmosphere instead of into the intake tract. Direct Product Link: http://minimayhem.com/shop/index.php?route=product/product&path=254&product_id=849
By expelling the charge air to atmosphere rather than recirculating it, you do not increase the intake air temperature but you do allow the turbo to keep spinning! Not only does it sound cool, it also helps keep your IATs cooler!