Modify your car with new NX Nitrous Kits. To get the most bang for your buck, invest in a Nitrous Kit. NX Nitrous Kits grab people's attention. A Nitrous Kit can double your horsepower depending on the size of your engine. An easy upgrade are NX Nitrous Kits. Make your vehicle much faster with a new Nitrous Kit. Nitrous Kits are the easiest way to add power to your vehicle.