You can spend the rest of your life studying whatever you want, running a magnet over a cars computer will not increase the power output by 35%.

As for your friends car, I can absolutely promise you that simply increasing or removing the rev limiter will not make 1 single more hp. Look at any dyno plot of an engine and you will see the hp level peak and then start to fall off right before it reaches the engines redline. That peak was the most power that engine can make with it's current configuration of cam shaft design, head/port design and compression. The further beyond that point, the lower the amount of power the engine produces drops until the engine destoryes itself. I'd personally like to see the dyno plot of a Pontiac Sunfire engine that can produce 190hp without the aid of nitrous or a turbo/SC. I also hope your friend doesn't live anywhere near me if he's driving 140 on a public road so he doesn't kill anybody I know or care about.