I was playing around with the AEMPro software (and the 1320 default map) and couldn't find the map for the MIVEC stuff anywhere, only the VTEC. Am i not looking in the right place???

could someone point me to the menu location for it?

 

It's in

Setup>Advanced Setup> Variable Valve Control (VVC)

 

There are two variable valve control setups, the Mivec uses #2. Also, keep in mind that the AEM reads in "units" of retard, not advance. And I say units because they are not degrees.

1.88 in the AEM map == full advance == 31 degrees of advance in openecu, etc.
14.69 in the AEM map == full retard == 0 degrees of advance in openecu, etc.

If you have a standard cam advance map from openecu, for example, you can convert the number by using this formula:

R = 14.69 - ((A/31) * (14.69 - 1.88))

R is the retard number to put in the AEM map, A is the advance number from openecu.

 

So lets try and understand this..

Advancing: Will Increase overlap and helps the cars bottom end and mid range power.

Retarding: Will Decrease overlap and helps the cars top end power

Why is that at idle, retarding the cam make it idle better?

 

You're only about half right.

The overlap comes at the end of the exhaust cycle and the beginning of the intake cycle. The cam that we have control over is the intake cam. So advancing it will cause more overlap like you said, but this is not ideal for low/mid power, it is ideal for high rpm power. Retarding the intake will decrease the overlap like you said, but this is more ideal for low end power because it cuts down on reversion. It should be obvious that if both the intake and the exhaust valve are open at the same time, and the air charge doesn't have enough momentum (low velocity due to low rpms) that there will be a fair amount of reversion which leads to a contaminated mixture, poor combustion, rough idle, etc.

Also keep in mind that lots of overlap is not ideal on a turbo motor at any engine speed. In an N/A application, the rushing out of the exhaust gas will suck in additional intake charge and "superfill" the cylinder. However, on a turbo motor, you will almost always have a greater amount of pressure in the exhaust than in the intake, so any amount of time during which both intake and exhaust valves are open you will again promote reversion because the exhaust tries to come back into the cylinder and dillute the intake charge, etc.