Quote:
|
Originally Posted by knucklesplitter
This is incorrect I think. My '04 STI (when it was bone stock) would audibly ping/knock with the factory ECU with bad gas and/or hot weather. My '03 WRX did this too with Cobb Stage 1 (only ECU reflash) and bad gas and/or heat.
|
I've heard the ol' STi popcorn machine coming from MattR's hood too on a bad tank of gas as well. However, I think that's an extreme case caused by a large change in parameters as seen by the ECU: i.e. the ECU can't instantly adapt to the sudden appearance of low octane fuel.
Under normal conditions, a car running up near knock will properly adapt and avoid audible pinging as the temperature increases, or as the humidity changes, etc, even on a highly tuned car. In fact, if you were to gradually lower your octane by adding 87 to the car a gallon every 50 miles or so, you'd probably be able to under-tune the car to run on that swill... assuming you don't mind a motor that makes no power.
As was mentioned, and as I found out the hard way, the ECU unfortunately can't react to anything above 6k rpm. Which is probably a contributing factor to why I spun a bearing when my car knocked at 7000 rpm at the last Lovelock Club Trials. But below that threshold, the ECU does a very good job at protecting the car under dynamic circumstances.