Hartge was a third party tuning company founded in Germany in the early 1970’s. They modified new BMW models for customers, much like Alpina, Racing Dynamics and AC Schnitzer. One of the earliest Hartge models was the H23 based on the euro 323i which was produced from 1983 to 1985 in Germany. They modified the engine with custom forged pistons that yielded a high compression ratio of 10:1 along with a new camshaft, exhaust and chip tuning. To top off all of the engine work, it was finished with a custom cast valve cover. Very few Hartge and Alpina cars were produced, and as a result the vintage tuning parts are now very sought after.