Volkswagen Sport Tuning: For Street and Competition (1975-1997), by Per Schroeder

• VW Corrado
• VW Fox
• VW Jetta
• VW Golf
• VW GTI
• VW Passat
• VW Scirocco
• VW Rabbit

FORCED INDUCTION

Street enthusiasts (few racing organizations allow aftermarket turbocharged cars to compete) can also use forced induction systems on their Volkswagens. By pushing air into the engine instead of letting it be sucked in by a vacuum, you can increase horsepower substantially.

This can be done in either of two ways: supercharging or turbocharging. A turbocharger is a combination of two turbines on the same shaft. One pumps air into the intake system, while the other is spun by the exhaust stream. A supercharger is a belt-driven air pump that just pumps air into the intake system.

There are few VW-specific superchargers available on the market today, but in the past, both the aftermarket and the factory have produced supercharger systems. Autotech developed a system in the mid-eighties, but dropped it later due to supply problems. Today, Bellevue Motor Sports offers a Paxton supercharger for the 2.0 A3 cars.

This kit will boost horsepower levels to near-VR6 levels at a reasonable price. The factory has developed systems for both the European Polo and the U.S.-imported Corrado. For those who are addicted to power, companies have started developing supercharger systems for the VR6 cars as well.

The turbo has been heralded as the best and worst in performance, depending on who you talk to. Historically, turbochargers have given huge horsepower gains, but have been plagued with short life spans and turbo lag that can be measured with a sundial.

Fortunately, most of the bugs have been worked out of aftermarket turbocharger systems, making them a good way to increase your VW's horsepower levels substantially. Earlier design bugs included inadequate oil cooling for the turbo, mis-sized turbos, and improper air/fuel ratios.

• The High Performance Volkswagen
• Suspension
• Wheels & Tires
• Brakes
• Intake Systems
• Ignition Systems
• Powerplants
• Exhaust System
• Lubrication
• The Water-Cooling System
• The Driveline
• Balancing Weight for Performance
• Safety Equipment Interior and Exterior
• Index