Dyno testing and the major magazines have shown that by replacing the stock unit with one of our 73mm units, you can expect 8 more rear wheel horsepower and as much as 11 additional rear wheel horsepower when installing our 76mm unit. The difference in performance is not primarily due to the increase in airflow, but rather through a slightly more refined calibration. The original 73mm units calibration was developed using flowbench and track test data. When the 76mm unit was developed, we decided to focus our calibration testing on the dyno, and this allowed us to find 2-3 more horsepower by fine-tuning the air/fuel ratio even further. The 73mm unit has been used on vehicles that run low to mid-10's in the quarter mile and generate as much as 600 rear wheel horsepower on the dyno. The 76mm unit will support the airflow needs of a 9 second quarter mile vehicle and will supply air to engines generating up to nearly 800 horsepower.