the return line is working fine i just test drove the car for 2 days allready . the turbo set to low to tap the oil pan as return point. NOW you mention the floper ....yes i know exacly what you mean and im thinking the same on that i dont know what route to go...(if i remove the floper what wud happend? ) is there a MAF convertion for my car?? if you know please gime me some imput.. ill post some video tonight running at 8 psi... it feels great but the A/F is jumping lean for a split second in 3rd gear and goin back to rich... i havnt conect the lambada o2 yet but i figure that injectors #715 are 23% biger than stock and the fmu shud compensate for the rest.... now i dont know if the stupid flopers in the intake or in the maf are the cause of this...what is your take on this...?
If you remove the flapper from the AFM, the car won't run. The ECU is calculating air mass from the calibrated flapper and the temp sensor (hanging down in the airflow). The TPS is likely only being used for accel enrichment, full-throttle enrichment, and overrun fuel cut (hard deceleration/coasting).
MAF Conversion:
http://bmw.e30tuner.com/articles_mafcon.phpThe flapper in the intake system (the DISA valve) should be disconnected so that it no longer operates. It has an electric vacuum solenoid connected to the ECU which switches over at 4800 RPM (going up) and 4200 RPM (going down). Disconnect the vacuum line to the solenoid and that should stop it from operating. Alternatively, you could cut the wire that goes to PIN #18 in the engine harness. That wire activates the DISA valve solenoid.
You really should have that WBo2 in there if you're driving at anything close to full throttle... I found my M42's stock NB sensor to be pretty far off. The NB would also give false data when the engine sputters or misfires... and continued to give bad data for a second or two after the misfire. If you're relying on the lambda sensor to make substantial mixture corrections (which it must be doing with the new injectors when NOT under boost) you should install the WB, program the output to simulate a NB and connect it to the ECU in place of the NB. You'll get MUCH better mixture control when that is set up.
I don't know, but I doubt that the ECU is using the O2 data to make any larger than a 25% change in supplied fuel, no matter how far away from stoichiometric you get. Seems like your FMU and larger injectors may be overpowering the maximum lambda correction MOST of the time.
Where is the spot where the engine goes lean? (RPM, estimated throttle position).
Can't wait to see a vid! Congrats!
