Attention: TDR Forum Junkies A friend of mine with a 2005 started toying around with a new DATAQ DAC unit tonight. The first transducer of interest was the fuel rail sender. Based on calibration values posted here somewhere (sorry to whomever I am not giving credit) and assuming a high degree of linearity, the data seems pretty reliable. By that he means within the expected 1% FSO after stacking all bias and offset errors as provided by DATAQ. He's a Mechanical Engineer geek so he's into all this non-linear system stuff.
Using a conservative sample rate of 240 Hz he was able to identify some pretty interesting transients upon smashing the throttle from a dead stop and from cruise. These will prove more interesting once the map sensor calibration values are dug up (anyone know where they can be found?) and the second channel is run in parallel with the rail pressure channel. That way fueling vs. boost can be observed in stock and 'bombed' trims. His truck is stock sans aFe filter and exhaust.
To wit: After the map sensor is wired in it would be even cooler to monitor wastegate solenoid duty cycle vis-a-vis the digital inputs to the DAC card and watch its behavior with boost. The curves are really interesting for what they are in their rough form, assuming that nobody else has Windaq software they've been converted to . CSV and . XLS for anyone interested, I've had a tough time posting those formats... Anyone help? The pdf is pretty gnarly because in a few minutes there were ~20,000 data points but the point gets across... Should have DFT'd it.
In short it will be nice to watch 1) a pressure box's behavior as compared to stock trim and see if the sender is being driven to saturation... 2) WG duty cycle under pressure box command... 3) low-end boost and fueling in stock and bombed trims... Also, with a simple 12-bit DAC accuracy was not of as great of interest as was transient behavior(s). PM me and I can email you the CSV or XLS files (or WDQ format if you have Windaq. ) He can also be emailed at -- email address removed -- if anyone else is interested in geek-speak. More to come with added channels unless I've put everyone to sleep in the meanwhile, thought this would be of interest to you common-railers who want to assess the physics behind the different boxes/methods...
Using a conservative sample rate of 240 Hz he was able to identify some pretty interesting transients upon smashing the throttle from a dead stop and from cruise. These will prove more interesting once the map sensor calibration values are dug up (anyone know where they can be found?) and the second channel is run in parallel with the rail pressure channel. That way fueling vs. boost can be observed in stock and 'bombed' trims. His truck is stock sans aFe filter and exhaust.
To wit: After the map sensor is wired in it would be even cooler to monitor wastegate solenoid duty cycle vis-a-vis the digital inputs to the DAC card and watch its behavior with boost. The curves are really interesting for what they are in their rough form, assuming that nobody else has Windaq software they've been converted to . CSV and . XLS for anyone interested, I've had a tough time posting those formats... Anyone help? The pdf is pretty gnarly because in a few minutes there were ~20,000 data points but the point gets across... Should have DFT'd it.
In short it will be nice to watch 1) a pressure box's behavior as compared to stock trim and see if the sender is being driven to saturation... 2) WG duty cycle under pressure box command... 3) low-end boost and fueling in stock and bombed trims... Also, with a simple 12-bit DAC accuracy was not of as great of interest as was transient behavior(s). PM me and I can email you the CSV or XLS files (or WDQ format if you have Windaq. ) He can also be emailed at -- email address removed -- if anyone else is interested in geek-speak. More to come with added channels unless I've put everyone to sleep in the meanwhile, thought this would be of interest to you common-railers who want to assess the physics behind the different boxes/methods...
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