Dinan High Flow Throttle Body - 2004-2005 BMW 645ci/2004-2006 545i/X5/2002-2005 745i/Many people seem to be under the false impression that the new Valvetronic engines don't have a throttle body. This is clearly not the case however the throttle body for these applications functions as part of the traction control system, as well as a ''safety valve'' of sorts. Regardless of the function the size of the hole still represents a restriction of intake air flow, making the larger bore of the Dinan high flow versions enable the engine to