Hondata

Hi,

How do I tune fueling?

I see 3 fields -
i) Target Lambda (Cat Protect)
ii) Target Lambda (VTEC) (Cat Protect)
iii) Minimum Lambda (Cat Protect)

1. How are these 3 fields different, and what do they mean, assuming I have a Cat to protect?
(My educated guess - i. & ii. are my target lambdas for VTEC ON/OFF, then I don't understand how "iii" inter plays with the other 2 fields.)

2. And if I set Minimum Lambda at 14.0, does that mean Lambda will stay below 14.0 (richer), or stay above than 14.0 (leaner)?

3. Then how do I tune fuel, if I DON'T HAVE a Cat to protect?
(Just tune in the same way, using the same 3 fields?)

Thank you.

The two target lambda tables are the lambda values the ECU will try to target if it is not running stoichiometric or trying to run richer for EGT reduction.

The minimum lambda is the minimum lambda that the ECU will target for EGT reduction. It is a minimum, so that means the ECU will not target below the values. ie richer.

Not running a cat does not make much difference to what lambda values you target.

sorry to bring this back from the dead but i was kind of in the same boat wondering if i can tune for better AF I did some data logging on a base map with prl intake. I noticed under boost it would read 12.4 12.5 12.1 11.8 11.7 anything over 12 makes me uncomfortable. @hondata any feedback?

11.7 on the top end is ok. If you want it to run richer then decrease the catalyst protection temperature to 500F or thereabouts. This will force the ECU to run richer. Then adjust the target lambda and minimum lambda tables. Also consider what the fuel trims are, especially with an intake, and adjust so that there is about -2% short term trim from 4500rpm upwards.

i have no cat to protect how can i just richen a little?

@hondata,

so you are saying raise cat protect temps then go in all 3 lambda tables and adjust where I want it to be a little richer.
for example if the target is currently at 12.7 that means it will not target anything over that only under so if I change that to 11.7 that means the ecu will only target under 11.7 never over correct? I'm so used to kpro and flashpro for older civics where we can just go into fuel tables and add or subtract fuel.

Thanks