|
Does anyone know what the OFT folks actually did to avoid pre-ignition? Pre-Ignition is pretty rare on a non boosted engine except if running at engine speeds lower than 1000rpm and very high loads. Now this entirely depends on the true dynamic compression ratio of the engine (not geometric). I have seen preignition in engine running 600rpm high load but that is only because we force the engine to run there for sake of calibration purposes.
What I am wondering is are we calling extreme knock as pre-ignition here?
Is it possible that these events are only seen during track day sort of events with high coolant temp and IAT and non-existent in normal circumstances?
If it is indeed PI the DI injection could be partly to blame for leaving carbon deposits. Then would it be a good idea to have a track day only cal utilizing mostly PFI to clean up the carbon left behind by DI to avoid PI?
As I understand changing spark timing does not solve PI since PI is independent of spark.
|