I just inherited my father-in-law's 97 Mustang GT which has a new (less than 2000 miles) Cobra engine sporting both a turbocharger and supercharger as well as many other enhancements which, in combination, produce approximately 650HP at the rear wheels. The engine runs great once I get it started, however the issue that I am having is that when I insert the key and try to start the engine, the starter doesn't respond. That is, until I disconnect the battery cable from the negative terminal and reconnect it. The battery is in the trunk due to space limitations. The car's actual mileage is 157,000+ miles and I am suspecting that the problem I am experiencing is related to the passive antitheft system. I believe that the ignition cylinder isn't recognizing (intermittent) the key and therefore disabling the starter. Once I disconnect the battery, it enables the starter and the car then cranks. Has anyone had any experiences like this? I hate to spend the money getting a new ignition cylinder replaced when that may not be the issue. Any thoughts? Thank you in advance for your input!!  

Sorry I don't have any solutions to your electrical problem, but please elaborate on your blown and turbocharged engine.