OnKill Tuning is a family operated speed shop in a suburb of Springfield, MO. Our goal is to help you make your vehicle everything you want. We offer EFI Tuning, performance parts sales, and high-quality installations. We specialize in EFI tuning, which is the process of optimizing a vehicle's fueling, ignition, and other subsystems for peak performance. Each engine is different from the moment it leaves the factory, and will see gains from a calibration written specifically for it. Whether you seek more power, fuel economy, or are building an all-out race car, we can use our experience to get your project across the finish line.