A 640 horsepower Audi SUV faces the hybrid Porsche 911 Turbo S in a clash of luxury performance and pure speed.

The 3-bolt 70-series turbocharger for the 3.8-liter Buick--track-proven to run easy 10.50s--has enjoyed lasting popularity with Turbo Regal racers. A couple of years ago, 10.50 was good enough to win ...

A turbocharger is the best power-adder by far. Not only do turbos harness otherwise wasted exhaust energy to drive the compressor, their modular nature lets compressor and turbine housings and wheels ...

Back in the last episode, we gained 50 rwhp by swapping to high-flow ported heads (Jose Motor Sports) and a hydraulic roller cam (Comp Cams). Our power gains were quite impressive considering there ...