The internal diameter of the stock throttle body is bored larger increasing the air flow area. The resulting increase in air flow provides more horsepower and torque throughout the rpm range, with noticeably quicker throttle response.
Dinan's High Flow Throttle Bodies improve intake air flow for additional horsepower and torque gains.
Throttle body is 3mm larger for an 8% increase in airflow area.
Stock bore = 79.5mm Dinan bore = 82.5mm
*Dyno results for the combination of Stage 3 Engine software, High Flow Throttle Body and Free Flow Exhaust.
Stage 3 Engine Software and Cold Air Intake Highly Recommended. Not applicable for 540i (E39) 1996 - 1998.