yeah another thing that people think is that they can set the VTEC lower, which will gain more power...but what they don't know is that the AFC merely tells the solenoid to engage earlier--- but doesn't tell the ecu that vtec is engaging earlier. So this results in horrid performance because the vtec lobe requires alot more fuel (obviously) than the non-vtec lobe-- and the ecu doesn't give the increase in fuel until the stock rpm that vtec should engage. Also, afc's are very very helpful in tuning turbo'd cars.