Hey "Fast Guy" No offence, but i'm right. Pinking is pre-ignition as you know, as is detonation. The two are very easily confused as they both have simular effects on a motor. The differance is Pinking is controlled, detonation isn't.
Pinking can be caused by a few things. Head gasket broken and a piece sitting in the cylinder, compression ratio too high for the grade of fuel being used, incorrect timing to name a few. Detonation, as the name suggests, is an explosion of the fuel. In an engine fuel DOES NOT explode like many think. The fuel burns, the heat of the air/fuel mix is what forces the piston down (compression) The differances in octane ratings is not how "explosive" the fuel is, its the burn rate.
Pinking usually happens when under load, so when it happens, back off. Detonation is random. As i said, GTi-Rs have a DET sensor, so unless its not working, the computer should do all the adjustments needed to stop this from happening.
Sorry about the long post, but i felt the need to defend myself. All this info was given to me by an engineer, not just a mechanic. He studies how engines work, the physics and chemistry behind it all. Then teaches it.
If you still don't agree with what i say, maybe we just have differant terms for it in Australia. But i seldom hear "detonation" used in Aus, but pinking or pinging often.
Besides this is getting too far away from the original question and probably confusing the poor guy.
Hopefully no hard feelings
