How different is the GT3 Engine from the Cup Car Engine?

How different is the 911 GT3 (992) engine from the 911 GT3 Cup Car? This is a question that is often asked by many Porsche enthusiasts. The answer? Not much! According to Thomas Mader, Project Manager for Porsche GT Road Car Engines, only the exhaust system and engine control unit are different. The new 992 GT3 street car now has the individual throttle control butterflies that come straight from racing. So the 911 GT3 engine is practically the same as 911 GT3 Cup Car! Absolutely amazing!