Quote:
Originally Posted by sachu
I would imagine most tuners would tune the car for an ignition map and then back off a say by 2 and put that number in the advance timing map and leave IAM at 1.
do any of the tuners have nothing in their advance timing map and leave their IAM at 1.0 and just trust their main ignition map instead? The retard is still in place and the fine correction is in place as well.
Or I am mistaken in understanding how most tuners would deal with this?
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Total ignition timing = base timing B + (Knock correction max A* IAM) + FLKC
most tuners set iam initial =1 . does not mean it stays at one.
When IAM drops due knock detections timing is reduced as the values in Knock correction max A table are multiplied by IAM.
I doubt any tuners would remove all timing (ie make table values zero) in the knock correction max A table as you would remove the ECU ability to adjust timing using IAM.
IAM is coarse correction and is meant to account for bad/low quality fuel or other problems that may result in consistent high levels of knock. It the ECU's last line of defence
In general your IAM should be 1 all the time if your tuned correctly and running correct fuel for your tune. Occasional minor drops in IAM like to 0.9 probably ok, but IAM consistently low like 0.7 or less consistently indicate your tune is too aggressive or the fuel your using is not matched to your tune.