Air Fuel Ratio (AFR)

[evo5755]

I think most of the the turbocharged are always concern about AFR.

With AFR we can see is the fuel running lean or rich. And it does co-relate to Exhaust temperature too.

AFR differs fro idling to your rev up all to the midrange and top. So, for those people are concerned with AFR, what AFR does you or your tuner require? 10,11,12 or maybe 13???what are the AFR value represents?

 

[am_izham]

AFR is exactly what the name says. it's the ratio of air to fuel ie: how much air needed per one unit of fuel to properly combust. in a perfect circumstances you need 14.7 unit of air (or oxygen) for every unit of petrol. but we're not in a perfect world, i'm talking about hundreds of variables such as the type of fuel, the compression ratio, the engine configuration itself, the target use, rpm range, heck even the weather and temperature plays part in engine tuning.

 

[lozo]

air fuel ratio (AFR) is simple the ratio between the amount of air over the amount of fuel.

for stoichiometric combustion of petrol is 14.7 parts of air to 1.

for maximum power from petrol, usually AFR is about 12.0~12.5 to 1. however as am_izham said, there are still other parameters that has to be take into consideration in engine tuning.
2 cents..

p/s pump in alcohol and strike it until 5 AFR..woohoo