For racing, the answer is yes. Fuel efficiency is not the object.
Originally Posted by IchabodCrane
All good points. There are manufacturers using headers (Chrysler era AMC 4.0 I-6 comes to mind). Mitsubishi isn't saving any weight using a cast-iron exhaust manifold though.
Originally Posted by Loren
Still, it'll be cool to see how yours turns out.
View my fuel log 2015 Mirage ES 1.2 manual: 50.1 mpg (US) ... 21.3 km/L ... 4.7 L/100 km ... 60.2 mpg (Imp)