Dear Stephen,
Can you look at any of the ECU inputs and outputs in real time?
I have a couple of zytec maps for a v12 but the ECU doesn’t elaborate on what the y-axis calibration is. I’d quite like to reverse engineer what they did for fuel and spark on the v12, but can only estimate the answer (from x-axis = rpm) by looking at the maps. I appreciate yours will be different, but it might give some insight into how they went about things.
kind regards
Marek
EDIT:- I might have some of these Lambda sensors in the loft.
We were told on conference call with a person who was associated with the original programming of the Zytek ECU that the data in the tables for fueling were in some varient / increments of clock tick time (or some fraction of that). So the clock rate Mhz would impact what that number should be and how many of them would relate to how long an injector’s “on” time would be - thus how much fuel it would put out at X pressure depending on the injector rating. Kind of… complicated…
Re those Titania chemistry O2 sensors, I was given to believe that out of the 5V supply to them, the signal returned would vary between near 0V and 4.5V depending on the resistance change in the sensor (unlike Zirconia sensor which self-generate a voltage up to 1V - generally between 0.2 and 0.8v).
Hi Paul
According to the sparse data out there on titania sensors, they receive 0-5 volts from the ecu, and return 0-.9 volts, which matches up with the data I saw on the laptop while we were driving.
It’s also upside down, where .1 is rich and .9 is lean. Only see 0 at idle. I hope this cures it!
Hmm… I hope so too. The swing you describe is the opposite of what you’d expect for a Zirconia O2 sensor, but the voltage output is… odd for what’s described for Titiania O2 sensors. Maybe it’s a special one with a different voltage divider circuit. Technically I suppose even a regular Titania O2 sensor could swing between those values with an input voltage of only 1V instead of 5V though, as the voltage swing can only be divided on the input voltage. Maybe it’s only being supplied with 1V?
Voltage from ecu to sensor is 0-5 volts. Voltage from sensor to ecu is .1-.9. 0 at idle in my car. Sensor works on resistance. Does not produce a current like zirconia sensor.
Paul,
I was only interested in how they handled the y-axis. I understand the actual data well enough for what I want already. For a normally aspirated engine using a MAP sensor, the y-axis would be 0kPa at one end and 100kPa at the other, but there is no indication of what the intervening increments are, so I have guessed at it. (On their v12 maps, the advance data looks to be expressed in 0.1 degrees and the injection data looks consistent to be seconds.)
I own a Euro specs Lexan F40 and an XJ220. My F40 feels quicker than my XJ220. Maybe the US F40 could be slower than the Jag because of slower specification than the Euro version.
My XJ220 is fitted with Garrett Turbos TB0389 and it is boosted to 1 bar of pressure. My F40 run 1,4 bar when overboosting and built with the hardest cam profile available for road cars.
