Overrun Fuel Cut Delay settings

[chneo1982]

There are 2 lean spikes whenever i shift as shown above.

From the log i estimated my gear shift to be around 0.5s.

What is a good overrun fuel cut delay time to eliminate these spikes? My current setting is at 180ms.

Please advise. thanks!

[Spunkster]

IT is normal to get a lean reading when you shift gears as you are no longer under load.

[chneo1982]

Then am I right to say overrun fuel cut only helps squirting fuel when decelerating to cool engine head?

How much delay would cause back firing?

[Spunkster]

You really do not want fuel spraying durring decel as it is not needed. It is shutting off as you can see in the datalogs.

[chneo1982]

I am trying to spray more and longer to cool the engine during deceleration.

Will this be bad for my O2 sensors?

[Hondata]

It washes the oil off the cylinder walls and causes ring wear.

[chneo1982]

But does it really help in cooling the engine? I am using this map only for track.

[Hondata]

Engine cooling is mostly moot when you have 70% leakdown.

[chneo1982]

What about a perfectly healthy engine?

[Spunkster]

He's telling you that washing the bores down will damaged the engine and negate any benefits.

[chneo1982]

I see.... thanks for the advice!