So I thought 12:1 was a good afr....I think it is, but I also thought that was running rich.....14.7:1 or whatever afr is ideal correct? on n/a...but for a boosted motor its more like 12.5:1 right? so which direction is lean and which direction is rich??? I was running almost an 18:1 on the dyno at WOT, so is that rich??
2000 Camaro V6.
| SLP Loudmouth | CAI Intake | HID's |
Whoa.....if your running 18:1 on the dyno you have some fuelling or tune problems. 14.7 Is stoichiometric meaning that you are getting the best compromise of power and fuel economy. However most engines make maximum torque with an AFR of 12.9. I'm not entirely sure with boosted engines but with the N/A engines I tune I aim for 12.9AFR. The lower the value the richer it is while the higher it is the leaner you are. AFR = Air:Fuel ratio. You definately have something wrong if your hitting 18:1.
Dallas Blake wrote:Whoa.....if your running 18:1 on the dyno you have some fuelling or tune problems. 14.7 Is stoichiometric meaning that you are getting the best compromise of power and fuel economy. However most engines make maximum torque with an AFR of 12.9. I'm not entirely sure with boosted engines but with the N/A engines I tune I aim for 12.9AFR. The lower the value the richer it is while the higher it is the leaner you are. AFR = Air:Fuel ratio. You definately have something wrong if your hitting 18:1.
not nesscaraly
first off oem 02 sensors are for lack of a better term "crap". they will tell the car if they are rich or if there lean. then it takes steps. so lets say that your car is 100 and that puts you at 16:1 the car will see that its lean and take a step down. so then your at say 95 and the car reads 15:1 it still reads lean so it will take another step. (mind you there are other steps for it to hit what it needs, but this is just an example.)
what this means for you is that the car has to take steps it just doesnt see what number its at and aplly fuel accoridingly. so it will tend to spike from times, if it gets to bad your car will take other measures. so dont worry your safe.
"
Kick azz is my boost hero!!! 
"
ok cool....but I'm still kinda confused....when my car was on the dyno it was shooting black smoke out????
2000 Camaro V6.
| SLP Loudmouth | CAI Intake | HID's |
My mistake, For some reason I thought he had a wideband. OEM sensors are narrowband and only read rich or lean, if you have black smoke and an indicated lean AFR than thats a bit concerning
yea they had the wideband hooked up when i was on the dyno.....and through 3rd gear it would spit black smoke out maybe 2 times.....
2000 Camaro V6.
| SLP Loudmouth | CAI Intake | HID's |
well black smoke usually means rich.
what most likely happened is that when you were railing on it on the dyno and then let off it was giving way to much fuel and did not compensate fast enough. hecne the extra fuel hence the richness hence the black smoke hence ummm...hence
"
Kick azz is my boost hero!!! "
Dallas Blake wrote:Whoa.....if your running 18:1 on the dyno you have some fuelling or tune problems. 14.7 Is stoichiometric meaning that you are getting the best compromise of power and fuel economy. However most engines make maximum torque with an AFR of 12.9. I'm not entirely sure with boosted engines but with the N/A engines I tune I aim for 12.9AFR. The lower the value the richer it is while the higher it is the leaner you are. AFR = Air:Fuel ratio. You definately have something wrong if your hitting 18:1.
not exactly true
stoichiometric is the point at which all the ari and fuel is completely burned to its effiencency.. Under WOT you want to be between lean best torque and rich best torque....rich best torque is safer on turbocharged engines because the extra fuel actually cools in intake charge allowing for more timing without knock retard.
18:1 i'm surprised you didn't blow up
really the only way to know whats best and safe for your motor is through tuning on the dyno
i have Boosted 2.2 ecotec.
What AFR am i looking for at idle, part throttle, and full throttle.
14.7.......dunno........11.8
holy post resurrection Batman!
Im supercharged, idle Im at 14.6 to 15.3, it fluctuates (might be due to the angle of my O2 sensor for the wideband on the downpipe).
WOT Im instantly 10.0...but I have a crappy tune right now and my car takes down fuel faster than Pamela Anderson taking down...well..you know..
I was told being supercharged, i should be around 11.7 or 11.9, ish.
04 Cav. 2dr. 5spd. My DD. 'Nuff said.
Oh wow! didnt notice it was such an old post.
Thanks! Yea i have to get a tune too once im dune DE bugging it.
