MP3Car.com - View Single Post - Calculating MPG from VSS and MAF from OBD2

jiggersplat · 10-30-2007, 08:21 PM

I would suggest trying to use injector pulse width instead if it is available. Not all engines run at stoich all the time. For instance, some of the lean-burn Civics run closer to 17:1 when cruising. Also, when you floor it and your car goes into open loop, you may be running closer 12:1 to keep from popping your motor. Or before your car is warmed up in the winter, it is probably running open-loop. Wiring in a wide-band O2 sensor to accurately read the A/F ratio in realtime in conjunction with your MAF readings would be more accurate than just assuming you are running at stoich.

10-30-2007, 08:21 PM	#10
jiggersplat Newbie Join Date: Mar 2006 Posts: 50	I would suggest trying to use injector pulse width instead if it is available. Not all engines run at stoich all the time. For instance, some of the lean-burn Civics run closer to 17:1 when cruising. Also, when you floor it and your car goes into open loop, you may be running closer 12:1 to keep from popping your motor. Or before your car is warmed up in the winter, it is probably running open-loop. Wiring in a wide-band O2 sensor to accurately read the A/F ratio in realtime in conjunction with your MAF readings would be more accurate than just assuming you are running at stoich. __________________ 2006 Corolla S • Ex-Audio 7" • Epia MII • ATI AIW VE • 512MB • Mini-Box.com M300 Case • 100GB 2.5" HDD • Z-COM XI-325HP+ • Linksys WSB24/WRT54G w DD-WRT • Treo 755p BT Modem • Lite-On Slotload DVD • GPS • JVC AVX2 • 2x JL Audio 8" • Alpine Type-S F/R