Shine it up and show it off with new Excel Nitrous Kits. To get the most bang for your buck, invest in a Nitrous Kit. We carry a great selection of Excel Nitrous Kits. A Nitrous Kit can double your horsepower depending on the size of your engine. New Excel Nitrous Kits set your car apart. Make your vehicle much faster with a new Nitrous Kit. Nitrous Kits are the easiest way to add power to your vehicle.