all depends on the experience of the tuner to how much horsepower and so forth you achieve, i know of more hp being made from a set of well tuned twin webers but with the driveability regardless of weather/humidity and temperature, just turn the key and your on your way, i did seriously think about twin carbies but for the price of a decent pair its actually not that expensive to compare efi and carbies. ill be tuning this my self and am thinking about doing some tinkering with e85 fuel aswell