I think I may be stretching my luck now
RPM vs. MAP (% Efficiency)
This map was SUPPOSED to be for a stock turbo, but I ran it on my t3/t4 60-trim at 10psi w/440's at 3bar. With a little leaning out up top the tune was pretty spot on as far as AFR. Pulled the motor apart and there was no problem with detonation on the piston tops, and I was non-intercooled as well.
It'll get you started/moving and driving fine. You'll have to f with it for optimal WOT tune, part throttle was pretty dead on for me.
firstname.lastname@example.org - VR6T
That's exactly what I wanted to hear
Regarding the factory IAP sensor...
Through VAGCOM - Adjustable Power Supply - Oscilloscope testing, I've determined the following sensor calibration:
0.3V = 120 mbar (first point)
2.7V = 1390 mbar (final point) - any higher voltage reports the same charge air pressure
Is this VAGCOM reported pressure relative to atomosphere? (just confirming)
What about when the engine is operating under vacuum (relative to atmosphere)? For example, at idle and negligible load.... How does the ECU determine spark advance?
That doesn't sound right regarding the voltage v boost. You should get up to +/- 2500mBar at 5V. Did you measure the voltage actually being applied - reason I ask is that the sensor wire from the ecu also carrys 5v which the MAP sensor sinks down to the voltage it is outputing.
Vagcom reports atmospheric + boost.
As for timing etc under vacuum, I think these cars are more MAF based than MAP. I think it uses the MAP sensor more just to control boost to match requested boost. If the MAF is unplugged then I guess it may use the MAP more - but not sure, I think it would actually just run directly from base maps (tables) in the ecu.
I am not claiming to be an expert, but that is what I have gathered from my experiences. Someone correct me if they know better.
My reported calibration above was read from the VAGCOM when the car was in accessory mode.
Maybe VAGCOM only displays up to 1390 mbar while in accessory.
The test was performed as follows:
The IAP pin was connected to the positive on the supply. The sensor ground pin was connected to negative on the supply. The power supply voltage was increased and reported VAGCOM pressures were recorded.
Maybe my testing procedure is flawed?
What does vagcom report just with the sensor unplugged?
Maybe the ecu realizes that the sensor is unplugged which messes with the results. I would try it with the sensor plugged in, splice the ground of the power supply to the sensor ground and disconnect the sensor wire and put your + power supply on there.
I think the sensor wire is battery ground, so you can pobably use any ground instead of splicing.
Modified by SAGTI at 8:28 AM 1-31-2007