Hondata

Hello all,

I am trying to get my head around something within the FlashPro software which was unexpected...

So my car has been professionally tuned, but I wanted to try and make the final 500rpm a little bit richer, just to be on the safe side. My tuner has targetted around 12.9AFR from 8500-9000rpm and I wanted richen this to around 12.5AFR.

To achieve this, I assumed I would adjust the WOT Lambda High table in the WOT columns and 8500+ rows..

However, this seemed to make the car unexpectedly leave closed loop mode and go to open loop, and my AFR went very lean at dangerously high rpm/load.

My car seems to be running in closed loop mode most of the time, which I presume is how my tuner has it set.
AFRs are really good and it very closely follows my AFR CMD line all the time, even when driving WOT... but as explained above, I would like to enrichen the very top end by 0.5AFR, but this seems to make my car go into Open Loop?

Can anyone tell me what the trigger for the car going into Open Loop is?
Thanks for any help

Graph 1 shows my AFR as 12.99 and fuel status as 2 (closed loop) and around 8500rpm (100% throttle WOT)
Graph 2 shows my AFR as 13.95 and fuel status as 4 (open loop)

However, I cannot determine why my car went into Open Loop - what was the trigger?

The only thing I altered in the map was richening my WOT Lambda High 8500+rpm cells to 12.5AFR

As can been from the two table attachments (before & after)

Does having AFR of 12.5 force open loop mode on the ECU?

I would bring you tuner's attention to the following line in the help file:

Important note: Do not use values above 12.50 (AF) or 0.85 (lambda), otherwise the ECU will always run closed loop.

So the vehicle has been tuned to run on closed loop at WOT, which is not normal and can cause many problems. I'd also like to point out that the lambda tables are correction tables, not target lambda tables.

Finally 12.5:1 is very rich for a NA vehicle. Peak power is around 13.2:1 and we've run vehicles at 13.8:1 for 25 hours continuously. Honda ran their turbo F1 engines at 14.7:1 @ 58 lbs boost...

Thank you for your reply - could I ask what problems this can cause?