Stock & orange ecu boxes can leave a bunch of HP on the table. They can be erratic and also are widely known to retard timing as the rpm's increase. So on a 450hp-600hp motor it's actually easy to see where a lagging box could give up 20hp-40hp in the upper range. So it's not that the Rev box adds hp it justs runs clean and correct and allows your motor to run better. Same with MSD, etc except it has a stock plug and look to it.