Grand National Nitrous Kits can improve the feel of your Buick. To get the most bang for your buck, invest in a Nitrous Kit. Street or strip, new Grand National Nitrous Kits keep your car one of a kind. A Nitrous Kit can double your horsepower depending on the size of your engine. Limited production, doesn't mean limited options - Check out our Grand National Nitrous Kits. Make your vehicle much faster with a new Nitrous Kit. Nitrous Kits are the easiest way to add power to your vehicle.