I might as well add my experience, dunno if it applies. Guy in a 300hp Ibiza Cupra R wanted a run, I pulled several car gaps in my 211bhp GT - three times. He then said it wasn't actually 300hp til he fitted this chip (he had a remote control looking this in his hand) and said it's actually 240hp. He didn't stand a chance though, oh his isn't an Ibiza but ah well! Said he'd race me once his chip was fitted but I think he sold it.