QUESTION on A/F reading

[GT_AUTO]

GT,

then by all means go ahead, it's just my suggestion that if you wanna place an AFR monitoring device, go wideband n however that's for tuning purposes only.... you can also place a permanent wideband into ur car but only if you can afford the cost of wideband sensor replacement....

i'm using standalone with AFR monitoring on narrow band, and it doesn't help me in tuning at all, the purpose of that O2 in my car is just for closed loop feedback to my standalone....

sky,

just my 2 cents, we take this as constructive conversation and not a sarcastic one, we can do anything to our car, but whether the cost vs gain benefits us or not is another matter....

nobody is saying nobody sarcastic here bro.maybe misunderstanding.just joking around only.that's y i said earlier.he want he's car to look cool mar(yaw yeng)so be it lor.:_: there's hardly any carburetor car with afr so it will look cool lor if he got one on his ride.wide band is only suitable for those modified with ems.cheers...........

 

[SkYwAlKeR]

yup,u need to drill hole to ur extractor.i thought ur using apex'i timer.hehehe...
i forgot liow how many wire leh the afr comes with.try ask those guy who sell
auto gauge meter in the market plc.connect the signal wire from the o2 to ur
gauge's signal receiver.happy modding.....

nola... the one asking about apexi timer not me.... his car already got ecu, so can directly tap the signal cable from there....

kenneth,yow yeng mar iswara using afr monitor.:_:.how many carburetor car
that u know using afr?hardly any right?won't blow a hole one lar on his piston.
the force always with him what........jj:shades_smile: no hard feeling skywalker.

hmm... vr sarcastic...
nvm nvm... jz some crazy idea of mine... coz learning how to tune AFR on carbie engines is kinda hard... coz most expensive workshop will use wideband O2 sensor while smaller workshop depends on the mechs knowledge and experience....
since i dun have all 3 the above, mayb a AFR meter can help me in my diy tuning... besides, by monitoring the close loop n open loop stuff in the AFR can help me save petrol on highway... (possible, according to hypertune tech talk latest edition about gauges reading)....

GT,

then by all means go ahead, it's just my suggestion that if you wanna place an AFR monitoring device, go wideband n however that's for tuning purposes only.... you can also place a permanent wideband into ur car but only if you can afford the cost of wideband sensor replacement....

i'm using standalone with AFR monitoring on narrow band, and it doesn't help me in tuning at all, the purpose of that O2 in my car is just for closed loop feedback to my standalone....

sky,

just my 2 cents, we take this as constructive conversation and not a sarcastic one, we can do anything to our car, but whether the cost vs gain benefits us or not is another matter....

vr true... but somehow, if this crazy idea of mine might possibly work, i would wanna see it comes true....

nobody is saying nobody sarcastic here bro.maybe misunderstanding.just joking around only.that's y i said earlier.he want he's car to look cool mar(yaw yeng)so be it lor.:_: there's hardly any carburetor car with afr so it will look cool lor if he got one on his ride.wide band is only suitable for those modified with ems.cheers...........

aiseh taikor, i wanna put AFR not because yau yeng la... if want yau yeng, i long time put whole sets of Defi meters, RSM, SAFC, VAFC bla bla bla whether it works or not....

but since kenneth siad narrowband O2 sensor cannot determine the AFR well, whats the use of it for actually??....

 

[deacon]

I thought Apex'i turbo timer gives readings in numerical fashion. Meaning if you're air fuel is tuned to 14.5 AFR then it will say that....

 

[kennethfong]

sky,

if i remember this correctly, cipan supercas in ZTH DIY forum posted a link for DIY Wideband device, u can try that it's quite cheap too (eerh i haven't tried so no guarantee)....

deacon,
yep, me using apexi turbo timer too, these air fuel ratio is using the narrow band O2 voltage to determine ur AFR, so it's just a prediction rather than actual data, furthermore the prediction can be calibrated if you wan, so dun trust that lerh....

 

[GT_AUTO]

yup,i agreed that u can't use the narrow band to tune ur car but to be frank,sometimes when u look at the reading on a narrow band o2 especially the 4 wire one,u will see that it's not far from the wide band reading.narrow band o2 on our car is to determine how much fuel been injected to the engine to retain optimized air n fuel ratio.narrow band o2 just roughly calculated the heat generated at ur exhaust.the higher the temp,the leaner ur engine burn n vice versa.wide band are more accurate that's why all tuner use it to tune high hp car. sorry for the misunderstanding sky n kennethfong.....:_:

 

[SkYwAlKeR]

yup,i agreed that u can't use the narrow band to tune ur car but to be frank,sometimes when u look at the reading on a narrow band o2 especially the 4 wire one,u will see that it's not far from the wide band reading.narrow band o2 on our car is to determine how much fuel been injected to the engine to retain optimized air n fuel ratio.narrow band o2 just roughly calculated the heat generated at ur exhaust.the higher the temp,the leaner ur engine burn n vice versa.wide band are more accurate that's why all tuner use it to tune high hp car. sorry for the misunderstanding sky n kennethfong.....:_:

yeap... thats what i'm thinking off.... when engine warmed up and u are driving steadily, does narrow band O2 sensor give a more accurate reading compare to idle rpm??... if the accuracy while driving is abit off compare to wideband O2, good lor... i can alwiz take the effort and drive around to monitor my AFR before retune it again... not necessory to idle and stay there to do tuning...

so, if exhaust gas is hotter, means lean mixture... if cooler, means rich mixture... okok... currently i'm tunining my carbie by feeling the exhaust gas... if got petrol smell or black smoke, means rich mixture... but for lean mixture i dunno whats the symptom....

sky,

if i remember this correctly, cipan supercas in ZTH DIY forum posted a link for DIY Wideband device, u can try that it's quite cheap too (eerh i haven't tried so no guarantee)....

icic... mayb during sioc yumcha i ask him more about it la... thanks for the info....

 

[D-IV]

Its normal. Why i say that is because its due to your old O2 sensor, why'd I say old? you said, engine was put in few days ago which i assume has undergone an engine transplant. Unless the A/F number doesn;t show up at all even though during driving, then i think its your wiring.

I've wired up a few cars already and usually new cars will show the A/F value under 1 minute of warm up (new O2 sensor y0). Hope that helps

 

[Choon]

yup,i agreed that u can't use the narrow band to tune ur car but to be frank,sometimes when u look at the reading on a narrow band o2 especially the 4 wire one,u will see that it's not far from the wide band reading.narrow band o2 on our car is to determine how much fuel been injected to the engine to retain optimized air n fuel ratio.narrow band o2 just roughly calculated the heat generated at ur exhaust.the higher the temp,the leaner ur engine burn n vice versa.wide band are more accurate that's why all tuner use it to tune high hp car. sorry for the misunderstanding sky n kennethfong.....:_:

the o2 sensor is just using the heat of exhaust? are u sure? not that the o2 sensor is detecting how much oxygen is left at the o2 sensor? and the volume of o2 affect the voltage output of the o2 sensor, no?

according to my knowledge, not necessary lean mixture will be hotter.. only to a certain degree. if the mixture is far too lean, the extra air (oxygen) will not be used to combust and this unused air will rob heat from the combustion process, thus lowering the combustion temperature.. correct me if i'm wrong.

i also like to noe how does this auto timer determines afr coz i wanan get one too to monitor my afr, i just need to confirm from wat signal this auto timer gets it's signal to determine afr. my car oni wira NA, so the timer is not really my main point, hehe.. i want the afr reading oni..

 

[SkYwAlKeR]

yea... o2 sensor is located at the extractor... den u expect it to be at the intake manifold there??...

if mixture far too lean, engine die oledi loh...
fuel has cooling effect... try rinsing ur hand with petrol, it feels cool... this helps reduce the engine temperature when running rich... this is because there are somemore unburnt fuel which soaks up the heat from the engine and dispose it thru the exhaust...

i guess autotimer gets its signal from ur car ECU....

 

[Choon]

yea... o2 sensor is located at the extractor... den u expect it to be at the intake manifold there??...

if mixture far too lean, engine die oledi loh...
fuel has cooling effect... try rinsing ur hand with petrol, it feels cool... this helps reduce the engine temperature when running rich... this is because there are somemore unburnt fuel which soaks up the heat from the engine and dispose it thru the exhaust...

i guess autotimer gets its signal from ur car ECU....

ya i noe O2 sensor at the extractor thr, but since it's saying 'theoretical air fuel ratio' so i dunno wheter it tap the signal from the intake or exhaust. if from exhaust, sure it will show the exact air fuel ratio wat.. then if taken from the intake, then reading can only be obtained thru calculation, so maybe the 'theoretical' term comes from thr :p

yep, i totally agree wit u.. too rich will have cooling effect.. the same goes to too lean..

 

[SkYwAlKeR]

ya i noe O2 sensor at the extractor thr, but since it's saying 'theoretical air fuel ratio' so i dunno wheter it tap the signal from the intake or exhaust. if from exhaust, sure it will show the exact air fuel ratio wat.. then if taken from the intake, then reading can only be obtained thru calculation, so maybe the 'theoretical' term comes from thr :p

yep, i totally agree wit u.. too rich will have cooling effect.. the same goes to too lean..

:hmmmm: u've seen cars with o2 sensor at intake manifold??... what engine is that??... :hmmmm:

intake manifold sensor is usually MAP (manifold absolute pressure) sensor... it takes reading on the amount of pressure in ur intake manifold... similar application with vacuum meter... MAP signal is needed to assist the ecu in calculating the exact needed fuel to be pumped into intake manifold...

as for theoritical theorem on what o2 sensor actually measures, i not vr sure... but o2 sensor output signal is 0-1v (for narrowband sensor) and 0-5v (for wideband sensor)....

 

[Choon]

hehe.. i'm not sure how the system works.. now i noe ad.. ;p