9FF GT9 R1 and 120HP

Serial Porsche modifier 9ff may no longer be in business, but for a while it did produce a mega 911 based special. Called the GT9 R, it sort of looked like a 911 if you squinted, with a lower, swoopier roofline and a big bodykit. That was to help keep it on the floor at 257mph the speed its 4.0 litre twin turbo flat six Porsche engine helped it achieve.