Quote:
Originally Posted by ONDEMAND
Hey man, your are getting there but it appears your logs are not 100% WOT. Your throttle plate (TPS act.) never seems to go over +/- 80% which would indicate you are not going full throttle. Please add "accel ped pos" to your list of data log channels so we can clearly see the relationship to what your foot is asking the engine to do and how the throttle plate position and loads relate.
How does the car feel when you do a WOT pull? Are you getting codes, or feeling a stumble? Perhaps you just want to know the engine is happy?
I assume this is a stage 2+ aggressive map given your mods and cotane?
In general your logs look decent. AFR is fine (no lean conditions) and timing corrections are minimal. On your second log there is a substantial correction in cyl 4 (-7) which could be a plug, coil, injector but I would not worry too much about that right now. Typically a couple degrees of timing pull is not really a problem -4 max, but this DME pulls timing under non WOT loads by nature. What you want to avoid is having multiple corrections greater thatn -4 on three or more adjacent cylinders when going 100% WOT.
I suspect you may feel the throttle closures when your throttle plate closes do to "actual load" exceeding "requested load". The "load" in these terms is an amount of torque requested by the DME based upon the input you provide at the pedal. The DME tables that dictate this load relationship can be adjusted via Cobbs "accesstuner" software or via a protune form Pro Tuning Freaks or the like. Remember the Cobb OTS maps are rather generic in nature and are made to suit the N54 or N55 across the board and in all altitudes. I highly recommend a Protune as the map will be revised to suit your specific engine, mods, fuel, and environment.
In the end you want to minimize throttle closures and keep timing corrections to a minimum. These engines are tough, tride and true + they have a ton of safeguards built in that will protect the engine, and in the process either pull timing or begin to limit air | fuel, or both.
Here is one of my logs showing minimal throttle closures even when Im exceeding the requested load of 190 and hitting 194. This is achieved by adjusting the torque load tables based upon pedal position. Note the flat line nature of "accel pedal pos", "TPS act." and the "requested load". Im holding +19psi to around 4,300 rpm and tappering down from there with the throttle plate never dropping below 98% open.
http://www.datazap.me/u/ondemand/ptf...&mark=51-60-23
Hope I dont come across like a dick but you need to add "accell ped pos" and log some 100% WOT (pedal to the floor buddy!) runs so we can really see what the engine is doing under max load. If you are truly going WOT in these prior logs and throttle is only at 80% then Im left scratching my head, this could be a more serious issue. Hopefully you just didnt put the pedal all the way down.
Good luck man |
This is not correct.
Cobb's datalogging maps the actual percentage of the throttle blade, which never exceeds 85% (and can never be 100%). We (Cobb people) all get readings of 80-85% TPS on WOT. It's not like the JB4 where it's measuring where the pedal is. Go to another website that has technology about your n54 information and you'll figure out pretty quickly that all of the above is not relevant. The boost is the only thing you should be concerning yourself with here and why it is at 11psi at less than 6000rpm on your pull.