Yep... I experimented with running it on my Rabbit autocrosser 1.6lTD. It doesn't work very well on the IDI VW Diesels. It was not really good for any significant reliable power gain reliably, and if you turned it up so that it gave a 5-10%'ish power gain, it would detonate heavily and cause engine problems. After blowing a head gasket from running with it detonating, I decided it wasn't enough power to justify the added weight, complexity, and reduced reliability. That is my take on it, anyway. The convoluted combustion chamber shape of the IDI just makes it too prone to detonation to be useful or reliable.