The turbocharger, or exhaust driven centrifugal supercharger, is the world’s most efficient power-adder, but it is also the most complex to install. It’s been six years since HOT ROD examined turbocharger design, selection, and system setup (see HOT ROD, Dec. ’03, Jan. ’04, and Feb. ’04). In that time the technology has continued to advance to the point that turbos in racing clearly dominate beltdriven superchargers or nitrous oxide. If anything, turbos used in competition have become victims of their own success: Rule makers have been forced to legislate against turbos, adding vehicle weight, reducing engine displacement, restricting the turbo’s size or numbers per engine, relegating turbos to a separate class, or even banning them entirely.
Meanwhile much of the technology previously seen only on high-end racing units has trickled…