Quote:
Originally Posted by TDIwyse
If you're referring to the latest plot above with the BMWhat logged "low pressure turbo" setpoint. This is the big turbo and shows what the DDE would be trying to target for setpoint from that stage.
|
If I am reading that graph correctly, the DDE target setpoint at 3500rpm is above 30psi gauge. Maybe I just learned something. That would seem high for a stock DDE. Do you think that target is a result of the remap in your DDE?
An example of an ECU map for wastegate actuation and the pressure ratio for the LP turbo is attached below. They are based on commanded torque and rpm (no surprise). I believe the link to this info was given before.
http://www1.eere.energy.gov/vehicles..._sweetland.pdf It is convenient to call out "stages", as is done in the BMW literature, but the maps really show wide transition ranges. Even the HP compressor bypass, which is essentially an on/off switch, varies by commanded torque and rpm. BTW, the HP compressor bypass and the LP wastegate maps are incredibly similar. The HP turbo isn't out of the picture until LP starts getting throttled back. When you have the skinny pedal to the floor I guess that does take out one of the variables.
Been following this thread, trying to understand what you wanted to see for boost at low, mid and high rpms, at high load. Clearly, there has been a concern about overdriving the turbo(s). I could have done a better job explaining my point. Your boost curve is "softer" in the lower rpms, in shape not absolute numbers. Sorry for being so thick about this, but what target boost curve are you trying to achieve ?
and are you seeing it (either on the analog gauge or by converting logged data)?
I admit I am having difficulty doing the conversion between the various sources of logs, text relating the analog gauge to the logs, etc. Not your fault, we can't seem to get the data we want and sampling rate, so I understand.
Keep the food for thought coming. My brain is hungry and I enjoy the soup that comes out of the TDIwyse kitchen.
