Alpha Performance R35 GTR Big Bore Billet Throttle Bodies - TB Set w/ Vibrant HD FlangesAt around 800HP, your stock throttle bodies become a restriction to the intake system. By enlarging the diameter of the throttle bodies from the stock 60mm (ID) to a massive 73. 5mm (ID), we increased the cross sectional area by 50%. This provides much improved power gains especially over the 1000HP mark. Maximum Airflow For Your Hungry VR38 Engine At around 800HP, your stock throttle bodies become a restriction to the intake system. The negative