F/A Ratios for our 4.0
#1
F/A Ratios for our 4.0
This may be a stupid question.....
When datalogging, how do I know when my pony is running lean / rich ?
Does anyone know where to lookup a good chart of (Fuel / Air /RPM ) chart ? is there a target ratio that has worked good for you?
Please feel free to teach us (me) "non tuners" how to understand this thing.
I want to be sure that after installing Mods, especially those that tweak the air intake and exhaust, that I am not doing damage to my engine b/c of fuel air ratios...
Thanks!
When datalogging, how do I know when my pony is running lean / rich ?
Does anyone know where to lookup a good chart of (Fuel / Air /RPM ) chart ? is there a target ratio that has worked good for you?
Please feel free to teach us (me) "non tuners" how to understand this thing.
I want to be sure that after installing Mods, especially those that tweak the air intake and exhaust, that I am not doing damage to my engine b/c of fuel air ratios...
Thanks!
#2
RE: F/A Ratios for our 4.0
I'm no expert but if the FA ratio was off after installing a CAI for example you would get a check engine light because the Mass Airflow Sensor would pick up the change (if it was out of spec). I'll probably get corrected on this but that's my understanding.
#3
RE: F/A Ratios for our 4.0
Thanks, I think you are correct.
the engine light is not on, but I also installed a performance tune, so I am not sure if the tune resets or tweaks the FA threshold params.
Once I install the headers and exhaust I want to datalog some runs and see where it falls.... It would be nice to know what ratios are considered safe running thru the rpm range.
I would love to take it to a Dyno for tune but there isn't one arround, so I guess I need to learn some basics before I go and start tweaking things with my predator.
I wonder if there are places that can analyze a diablo sport Log and create tweaks for the tune (sure is not exact science, but I have no better alternatives).....
the engine light is not on, but I also installed a performance tune, so I am not sure if the tune resets or tweaks the FA threshold params.
Once I install the headers and exhaust I want to datalog some runs and see where it falls.... It would be nice to know what ratios are considered safe running thru the rpm range.
I would love to take it to a Dyno for tune but there isn't one arround, so I guess I need to learn some basics before I go and start tweaking things with my predator.
I wonder if there are places that can analyze a diablo sport Log and create tweaks for the tune (sure is not exact science, but I have no better alternatives).....
#6
RE: F/A Ratios for our 4.0
Stoichiometric (optimal) f/a ratio is right around 14 if i remember correctly- like 14.2 or something. Running Lean will cause premature detonation. Running rich is safer, but causes quicker carbon buildup on internals. Also will cause a cooler burn inside the chambers.
Get a wideband O2 sensor and gauge to really keep tabs on that if your doing heavy modding. Wideband O2 is a 3 wire sensor, its got a signal, a ground, and a heater wire. It will give you a broader scanning range than a normal air sensor and will give you a sure fire readout that you can rely on.
Edited for accuracy.
Get a wideband O2 sensor and gauge to really keep tabs on that if your doing heavy modding. Wideband O2 is a 3 wire sensor, its got a signal, a ground, and a heater wire. It will give you a broader scanning range than a normal air sensor and will give you a sure fire readout that you can rely on.
Edited for accuracy.
#9
RE: F/A Ratios for our 4.0
ORIGINAL: zorminster
Stoichiometric (optimal) f/a ratio is right around 14 if i remember correctly- like 14.2 or something. Running rich causes premature detonation (Almost as bad as premature something else....) and Running lean will cause something equally bad, just can't remember what.
Get a wideband O2 sensor and gauge to really keep tabs on that if your doing heavy modding. Wideband O2 is a 3 wire sensor, its got a signal, a ground, and a heater wire. It will give you a broader scanning range than a normal air sensor and will give you a sure fire readout that you can rely on.
Stoichiometric (optimal) f/a ratio is right around 14 if i remember correctly- like 14.2 or something. Running rich causes premature detonation (Almost as bad as premature something else....) and Running lean will cause something equally bad, just can't remember what.
Get a wideband O2 sensor and gauge to really keep tabs on that if your doing heavy modding. Wideband O2 is a 3 wire sensor, its got a signal, a ground, and a heater wire. It will give you a broader scanning range than a normal air sensor and will give you a sure fire readout that you can rely on.
oops.. you have that reversed... running LEAN can cause detonation....
#10
RE: F/A Ratios for our 4.0
Thanks everyone,
I am going to order the AEM’s Gauge-Type Wideband UEGO Controller.
Looks really good and it is a way fo me to keep my eye on the mixture since I do not have access to a dyno shop.
I am going to order the AEM’s Gauge-Type Wideband UEGO Controller.
Looks really good and it is a way fo me to keep my eye on the mixture since I do not have access to a dyno shop.