One of the problems we've run into running big horsepower packages is that they aren't always controlled by street-friendly hardware. Take in point the typical fuel system needed to run 400 or more horsepower. These big thirsty fuel pumps run great at wide open throttle, but at part throttle cruise or idle they're just pumping away, shortening their life and making a lot of noise. One way to combat this issue, whether you are carbureted or fuel injected, is to slow down the fuel pump during off-peak demand. Professional Products' [www.professional-products.com; (323) 779-2020] new FuelOnDemand module is just the ticket. Wire this unit up, install the fuel pressure sensor and map sensor and let the FuelOnDemand module control your fuel pressure. Non-liner targeted fuel pressure control means you can program the module to increase fuel pressure at certain engine vacuum or boost levels, perfect for getting more fuel without maxing out your injector size.