A/F ratio

[Angermangement890]

14.7 is considered perfect burn or "stoic condition" for gas engines ,that number should not fluctuate w/ boost or octane rateing after inital tuning. How ever changes in boost or altitude will have bearing on this number. One will want to dial in stoic at high load and w.f.o., Also, In A sled you may want to find a guage with tattle tale or memory.

He is right, stoic is 14.7, most efficent burn, but he missed the section where peak power is usually around 12.7 AFR. My car runs a consistent 14.2-15.5 in cruise situations, once the hammer is down, it drops to 10.8-12.5 depending on my fuel type and ECU calibrations. Pump gas 91 octane I have found to like a richer AFR rather than a leaner one 10.5-11.2, E85 is happy at 12.5-13.0.

A bit of info, the Bosch LSU wideband sensor is very fragile, I prefer the drop it on its head tough NGK sensor. The NGK powerdex AFX set up can use both sensors, most other widebands you are stuck with the Bosch unit. I also prefer the heater circuit in the NGK over the AEM and Innovate units, the sensors last much longer and are more precise over the others. Its very easy to tune with the "good" sensor and then install the cheap unit for day to day running.

 

[666drifting]

so stupid question maybe, do you guys run the 02 sensor all the time or just occasionally to tune and check up?

 

[NoSecondChances]

Is the longevity issue with the sensor or the gauge itself? The sensors are only about $125 to replace (Bosch ones anyway).

If you pull the sensor and clean it (with fuel?? carb cleaner??? just guessing?) will it last longer?

Are you guys using the heat sinks with the 2 stroke pipes or just installing a sensor (heat sink is supposed to make sensor last longer from what I understand)?

Thanks,

NSC

 

[m8magicandmystery]

just finished riding with the koso a/f...i also have the koso dual egt...my a/f is mounted at 2 oclock in the fat part of pipe with extended heat bung...and i put power through a toggle switch so i just flip it on after a minute when the heat bung is hot and she is reading excellant..i have established prior by plug and piston that i really do not want my egts to exceed 1260..early indication is af will be 14 low(green)( 13 to 13.5 accellerating/cruise (yellow) 12 to 12.5 3/4 to wot (red)..its just a question weather the pl box is capable of the fine tuning...i may have to go to a boondocker