This is how Jools (Spitfire4v8) does it on his rolling road with an AFR gauge, a windows laptop and an ECU interface that plugs into the ECUís tune chip socket.† Jools plugs a RoverGauge cable into one USB socket and the ECU interface into another USB socket. He then runs RoverGauge and TunerPro simultaneously as in the screen shots below.
RoverGauge highlights active fuel table cell & TunerPro to change the active cell
TunerPro updates the fuel settings in real-time even with the engine under full load and the changes take immediate effect. My understanding is that Jools holds an engine at each load point in the fuel table while adjusting the fuelling inside the ECU, via TunerPro, until the AFR is correct.†† This process is repeated for every cell in the fuel table. The ECU interface is called a Moates Ostrich and it emulates and updates the tune chip it replaces, they are currently on ebay for about £130 inc P&P .
Once youíve finished working on the fuel map with TunerPro you have to save the changes to a file on the hard disk and then burn the saved file to a chip as in the simplified instructions .
I've finally proved this approach actually works with the 14CUX and is very accurate, however it does involve buying and welding an Air Fuel Ratio probe into your exhaust or Y piece. There are numerous wideband AFR sensors/controllers on the market ranging from £150 to £200 but please check compatibility with the AFR logger on the 14CUX Remapping Gadgets page.
You connect the RoverGauge cable to one USB port and the AFR controller to another USB port and then run the RoverGauge logger and my AFR logger simultaneously and go for a drive. When finished driving the two data log files are merged together based on the laptop system time for every record in the log files.
During the summer I was manually merging the logs but one day I plan to automate the merge and output a 16 by 8 table, like a fuel table but with the AFR readings.† You can then use your AFR readings at each load point in the fuel table to correct the fuel table cells with TunerPro as necessary. Finally when ready use the simplified instruction above to copy the updates to a chip for normal use.
Merging the logs manually proved very time consuming but useful as I discovered how advanced the 14CUX is and that the AFR readings are about 0.15 seconds behind the RoverGauge log readings. I could see suddenly hitting the throttle caused an instantaneous short burst of extra fuel that has to be ignored during the merge. This highlights driving smoothly and steadily will increase the accuracy of the logged data. For example if you want to log full power donít kick down the throttle instead ease it down smoothly.
Merged RoverGauge and AFR Logs
For further information on the software and gadgets please read Software and Gadgets required to Remap the Lucas 14CUX .