Top fuel runs 6500+ hp with a single roots type charger. 6500 hp will light up some big tires and not just from a stop, at 330 mph too. I don't see why anybody would want anymore power. Twin turbos make sense beacause you can run too smaller turbos to eliminate turbo lag - as bigger turbos lag more. But back to the point, 2 superchargers wastes gas, one will do the job.