Cold air is good. Hot air is bad. Every gearhead, young and old, is familiar with this line of thinking. We buy hoodscoops, cold-air intakes, and all other manner of contraptions to help feed our ...

The previous installment of this seemingly endless project covered the new 3.2-liter motor and larger Active Autowerke's turbo installation. Not surprisingly, the engine has even more power, but with ...

So what do you do when you've built your motor, strapped on the biggest turbo you can tolerate and basically tuned your forced-induction car to the teeth-but you still want more power? More boost ...

The BMW M4 GTS is one of few production cars to use a water injection system. The M4 GTS sprays water into the intake manifold to cool down air for its engine. How in the world does water help make ...