AFR goes lean when accelerating, only on closed loop *pics*

[crucian]

I assuming that u are using a wide-band AFR for your road tune :)
Just to share some stuff I pick up from using the S300.

1) Target Lambda target is not useful for tuning. This is because when u throttle off, the reading of the AFR are taken in account, resulting in inaccurate output.
What I do is that I hold the throttle at a constant position untill the AFR reading does not fluctuate much, take note of the AFR, RPM and MAP senor reading. Then adjust the values of the cell and cells around it.

2) Another thing to do for tuning in close loop is to change the short term fuel trim adjustment to 0% for both min and max before tuning. Once u r done w tuning, revert back to the original settings. This is to prevent the ecu from interfering adjusting the fuel during your tune. (Do remember to reset the ECU before tuning to remove any long term trim adjustment)

(There are too many variables in open loop tuning which need adjustments. eg. ECT, IAT, fuel and ignition compensation. Keep it simple by tuning in close loop with above settings)

love the mini with the boosted B engine. Should be fantastic fun!

Actually, if used right, the target lambda function is a great tool. I have tune numerous cars using the target lambda, for cruising or WOT, and got AFRs dead smack on with no fluctuations. If you haven't noticed, people on this website still seem to have problem with the closed loop function. I think the only way to get your engine running how you want it to run is to master open loop. Take full control of your engine. Don't let your ECU out-smart you; you out-smart your ECU.

[Will_B18C]

I assuming that u are using a wide-band AFR for your road tune :)
Just to share some stuff I pick up from using the S300.

1) Target Lambda target is not useful for tuning. This is because when u throttle off, the reading of the AFR are taken in account, resulting in inaccurate output.
What I do is that I hold the throttle at a constant position untill the AFR reading does not fluctuate much, take note of the AFR, RPM and MAP senor reading. Then adjust the values of the cell and cells around it.

2) Another thing to do for tuning in close loop is to change the short term fuel trim adjustment to 0% for both min and max before tuning. Once u r done w tuning, revert back to the original settings. This is to prevent the ecu from interfering adjusting the fuel during your tune. (Do remember to reset the ECU before tuning to remove any long term trim adjustment)

(There are too many variables in open loop tuning which need adjustments. eg. ECT, IAT, fuel and ignition compensation. Keep it simple by tuning in close loop with above settings)

love the mini with the boosted B engine. Should be fantastic fun!

Actually, if used right, the target lambda function is a great tool. I have tune numerous cars using the target lambda, for cruising or WOT, and got AFRs dead smack on with no fluctuations. If you haven't noticed, people on this website still seem to have problem with the closed loop function. I think the only way to get your engine running how you want it to run is to master open loop. Take full control of your engine. Don't let your ECU out-smart you; you out-smart your ECU.

Care to share how did you use the tgt lambda in ur case? Like how prevent the valves from begin logged when throttle off, besides setting the throttle percentage and speed. I agree it's a great tool if I can get it to record only the info I need.

I suppose in ur case, u never revert back to close loop at all?

[crucian]

Care to share how did you use the tgt lambda in ur case? Like how prevent the valves from begin logged when throttle off, besides setting the throttle percentage and speed. I agree it's a great tool if I can get it to record only the info I need.

I suppose in ur case, u never revert back to close loop at all?

I would just have the driver hold throttle while I tune and just keep resetting the values. After a while it becomes natural. I never went back to closed loop. Been running open loop from the time the S300 came out. I'm currently deployed to Afghanistan, so I can not go out and do any kind of testing. But every car I've tuned, I was able to get the AFR dead on using target lambda. I used it basically for a guide, and then I touched the rest of the map up from experience.

[Johnny_9]

your STRIM rate of change looks to low and slow.