wat is AFC arr

[kiran84]

hey all the mafia out there....................

wat is AFC actually for arr...........

 

[L2TurboFool]

Air Flow Control?

 

[flamefox850]

air fuel convertor. for apexi s-afc..just add super in front :D

 

[L2TurboFool]

i'm very curious...what does it actually "convert"??haha

 

[flamefox850]

it convert the signal from map sensor to ecu lah.
if map sensor read 0.8bar then u add +20% on safc then gives at around 0.96bar...then ecu order the injector to inject more fuel to support 0.96bar of what it sees from safc

the figure is not accurate..only my assumption

 

[pang]

good info flamefox...

 

[aiM]

just say it we can tune the air and fuel like carb. because fuel injector cant be tune like carb without a proper tools. or in the other words, save fuel, more power, bla bla bla.. see who setting lah hehehe

 

[drexchan]

Originally posted by flamefox850@Feb 8 2005, 23:35
it convert the signal from map sensor to ecu lah.
if map sensor read 0.8bar then u add +20% on safc then gives at around 0.96bar...then ecu order the injector to inject more fuel to support 0.96bar of what it sees from safc

then wouldn't the O2 sensor sense the rich misture and re-direct the ECU to cut the fuel (by increasing the duty cycle of the injectors) during close-loop operation?

if so, then AFC is useful only during ecceleration but not cruising.

correct me if i am wrong.

Let's assume that i am right. Wouldn't an adjustable FPR (at much lower price) do the same job?

 

[flamefox850]

hmm O2 sensor or ext temp sensor gives signal to ecu..when got rich signal..it told ecu to lean it...but it only TRIM it i think..trim then only little precentage only. so, if u adjust the safc into too rich..then O2 sensor cannot told the ecu to lean it too much until it going into STOICH mode. this is what i think...expert pls gives out comment

if the O2 can really2 help ecu to get stoich mode..then no need safc or other fuel management right ? B)

p/s: adj fuel regulator only adjust the fuel pressure..and fuel pressure increase as boost increase too...so if u adjust so high..u got rich mode in all rpm..be it at idle or high rpm or high boost

 

[drexchan]

Originally posted by flamefox850@Feb 15 2005, 00:17
hmm O2 sensor or ext temp sensor gives signal to ecu..when got rich signal..it told ecu to lean it...but it only TRIM it i think..trim then only little precentage only. so, if u adjust the safc into too rich..then O2 sensor cannot told the ecu to lean it too much until it going into STOICH mode. this is what i think...expert pls gives out comment

if the O2 can really2 help ecu to get stoich mode..then no need safc or other fuel management right ? B)

p/s: adj fuel regulator only adjust the fuel pressure..and fuel pressure increase as boost increase too...so if u adjust so high..u got rich mode in all rpm..be it at idle or high rpm or high boost

normally the compensation rate from the O2 sensor is about 10%. Meaning the ECU is able to increase or decease the fuel feed by 10% from the MAP setting. If AFC adjusted it too high then the ECU will not be able to adjust the feed.

A-FPR.. hmm yes you are right. But remember there is this little O2 sensor that do the trick. At idling or cruising at part throttle, the engine is governed by close-loop operation. So no worries or lean or rich IF the fuel pressure isn't too high. Only when the engine is eccelerating, the mixture will become rich.

Alternatively, one may try rising rate FPR (RRFPR) or sometimes called FMS (fuel management system).

 

[flamefox850]

yerp..u r correct :)

 

[gunter]

Good gadget to have.. it actually gave me good FC.. and increased hp's.. but need to be coupled with other mods to gain full advantage of this device.. cheers..

 

[taqu]

AFC works by intercepting airflow signal from engine, modifies it, then sends the modified signal to ECU. ECU, upon seeing the modified airflow signal, will "think" actual airflow is higher or lower, then it will lookup into different location inside its fuel map. I guess Proton or most other stock ECU have airflow data lookup values for upto 50% higher than regular fuelling requirement, that's why AFC works. Go above 50%, the stock ECU might go crazy coz those "altered" airflow signal may no longer exists inside its fuel map. So AFC is a good solution if ur modifications doesn't require u to increase fuel over 40%.

I wonder if someone can do this thing the other way around, instead of modifying airflow signal from AFM/MAF/MAP sensor to ECU, why not modify injector timing from ECU to injector? That could give much wider tuning range than 50%.

 

[TE27levin]

but the stupid S-AFC will bring dis advantage to 2 bar MAP sensored car.

when ur turbo boost 0.8bar u increase SAFC to 20% richer then ecu will cut off the fuel supply because it reach the 1bar boost cut. LOL!!!

 

[stroker_kit]

thats when an FCD(fuel cut defencer) comes in handy... mods just doesnt come cheap nowadays... :(