Diesel engines need two things to make power: air and fuel. We know that's grossly oversimplified, but it's true. If you increase the engine's ability to ingest air, you can add more fuel and thus ...

The MK2 Focus ST gets a full turbo-back exhaust system upgrade with an Airtec downpipe. In this video, we go step by step ...

When it comes to efficient power-adders, turbocharging is hard to beat. Rather than rob power from the crankshaft to spin a blower, turbochargers harness wasted exhaust energy to make boost. This ...

This video covers the full process of installing a Quicksilver exhaust system on my Porsche 911 Turbo S, along with sound clips and driving impressions after the upgrade. The goal: unlock more ...

In a diesel engine, adding more fuel will almost always result in more horsepower, and last month, that's exactly what we did in our "Fuel It Up!" article. There are drawbacks to making power in this ...

In Part I of this story (Jan. '06), we introduced the Squires Turbo Systems (STS) rear-mounted turbocharger package for the '98-'02 LS1-powered Firebirds. The base STS kit retails for $3,995 and comes ...