Spiess Tuning
From Infogalactic: the planetary knowledge core
Spiess Tuning is the common identity of Siegfried Spiess Motorenbau GmbH, a motor vehicle engine tuning company based in Ditzingen, Baden-Württemberg, Germany. Today Spiess Tuning is most famous for its Formula 3 motor racing engines based on the Opel Family II and two iterations of Volkswagen R4 engines.[1]
In addition, Spiess has worked on many different engines with motor racing applications, including a 4.0 litre V8 for use in the DTM Opel Vectra.[2]
