Today, we find out what it'll take to make a $30,000 titanium exhaust from scratch. It'll have to handle north of 1300 horsepower and fit the world's fastest McLaren, my flooded P1 "Evo".

Porsche then showed the 918 lap unedited, a 6:57. Even so the P1 is a searingly quick car on road, race circuit or in a straight line: McLaren claim 0-62mph in 2.8-seconds, 0-124mph in 6.8-seconds ...