Fair enough. Changed it to 60.

 

copied and pasted from n54tech general help sub-forum (not specific to our car):

there are 2 ways to enhance the amount of fuel injected of such engines:
- raising the injectors opening times (by flashing the DME, the JB4 don't do that).
- raising the fuel pressure in the injectors rails (Open loop fueling) by the HPFP.

open loop or closed loop are 2 states of the lambda sensors adjustment.
when the engine is on closed loop state, (ie low throttle for example), the DME reads the lambda value to adapt the trimings.
when the engine is on open loop state (ie Wide Open Throttle), the DME no more reads the lambda sensor value and is injecting fuel as the map on the DME is calibrated, without any adaptation of trimings.

Open loop fueling is a JB4 function which allow the HPFP (high pressure fuel pump) to enhance the fuel pressure in the injectors rail, in order to enhance the fuel amount injected when the engine is at WOT, where there is a lot fuel needed, to keep you AFRs rich enough.

by default Map 5 have an auto-adaptative Open loop fueling.
but we can set it manually (futureuseB=2 with iso boards) if we have 29F2 limp mode code which indicates the OLF setting is too high.

lowering the OLF setting manually will put less stress on the HPFP, avoid 29F2 codes, but will lead to highers trimings.
If trimings are maxing out (IE >50 on the JB4 log graphs), it's not good too, as the DME can't control the fuel amount.

 

Wow. Thanks for that... I guess I was searching for info specific to my make.
So where are people getting that you want 50 if you're using a flex fuel cable and 60 otherwise? What's the max pressure you could safely put on the fuel injector rails? How does Octane play into this? It sounds like there's a built in fault code that lets you know if you are putting a setting open loop too high.

 

it's all part of this tuning game. it's trial and error. seems you lower the fuel open loop as you increase the psi to compensate for the additional need of fuel. keep in mind that this burger tune is tricking the ecu, so in reality the ecu thinks it's truly delivering x psi and not x+3. that being said, the fuel open loop forces it to push more for the extra psi that WE know we are giving it.

i can only guess that some of these guys have been playing with BMS kits in previous generations BMW's and know some of the tricks of the trade.

IMO, and i hope someone can correct me, i dont' think octane plays a part in the fuel open loop. seems to me that it's directly related to the PSI increase. the higher octane increase the combustion but it's still the same amount of fuel. that is unless the mix of e85 with regular gas requires a different value int he fuel open loop to adjust due to different type of gas (e85 mix)

PS. this is my interpretation of this and by no means fact. i know enough to break sh*t.

 

Just kicked mine up to +5 boost. My tires are not happy

 

So what exactly did you do? Did you mess with the fuel open loop or did you just change your boost level?

 

Spoke with Terry and he said adjust the boost only. Leaving it here for a while then going for more

 

Nice, so on the reinstall did you just plug everything up the same way?

 

Never uninstalled it...laptop to module...change boost.. Hit save..done