apexi safc2

[4ndee]

does anyone use one? what do they do?

[Ryan S]

it's just a device to control air/fuel mixture at certain revs, they're for cars with air flow meters i believe

[4ndee]

does it display afr? i just read the manual online looks like a good bit of kit. anyone got one

[Ryan S]

does it display afr? i just read the manual online looks like a good bit of kit. anyone got one

yeah was just having a nosey too, it does look as though the AFR is displayed, dunno how much latency there'd be though, i can only assume they would try to make it show as much in real time as possible, i'll keep looking as it's quite an interesting bit of tech

[Turbonoz]

No, it doesn't display AFR.

The SAFC2 is an old-school piggyback device that modifies the load signal from the AFM. This in turn affects timing adversely.

I had one in my old S13 back in 2006 before Nistune was readily available, simply to monitor the AFM voltage. Their knock sensing capabilities are useless as well. Overly sensitive.

[Turbonoz]

P.S. Your sig quote is taken out of context. Grow up mate.

[4ndee]

my sig? confused

[Turbonoz]

my sig? confused

Not you mate!

[4ndee]

i see now

[leary123]

i had one of these fitted in a colt that i turbo charged with a wideband to go with it ..(so no there is no afr on the safc 2)..

these units only work on wide open throttle when the ecu stops using sensors and relies on pre built maps and ignores correcting via sensors.

the safc managed to blag me through an mot emission test by altering the fuel at idle but only just..the reason being is that if you alter the afr ratio then lambda sensor picks up a reading that is not stoich and so corrects the fuel trim and basicly undoes what you have set in the safc...most cars will allways want to run at stoich so matter what you do the ecu will notice the change via the lambda and correct...the only time it does work is when the ecu hits closed loop and stops using any sensor input...which is often full throttle and high ish rpm.
with the mot i managed to just catch the emissions and lambda on the green for 5 second before the ecu undid my safc correction..although it took 8-9 attempts to catch it for 5 seconds.

its not that they dont work, because the do what they say they do but dont expect any major results from it it... and i wouldnt mess around with high end wide open throttle fueling unless you have wideband lamda to go with it.

[Turbonoz]

i had one of these fitted in a colt that i turbo charged with a wideband to go with it ..(so no there is no afr on the safc 2)..

these units only work on wide open throttle when the ecu stops using sensors and relies on pre built maps and ignores correcting via sensors.

the safc managed to blag me through an mot emission test by altering the fuel at idle but only just..the reason being is that if you alter the afr ratio then lambda sensor picks up a reading that is not stoich and so corrects the fuel trim and basicly undoes what you have set in the safc...most cars will allways want to run at stoich so matter what you do the ecu will notice the change via the lambda and correct...the only time it does work is when the ecu hits closed loop** and stops using any sensor input...which is often full throttle and high ish rpm.
with the mot i managed to just catch the emissions and lambda on the green for 5 second before the ecu undid my safc correction..although it took 8-9 attempts to catch it for 5 seconds.

its not that they dont work, because the do what they say they do but dont expect any major results from it it... and i wouldnt mess around with high end wide open throttle fueling unless you have wideband lamda to go with it.

Turbocharged cars don't always want to run stoich, they would self-destruct very quickly if they did. Turbocharged ECUs remain in closed loop (i.e. lambda feedback, 14.7:1 stoich) at low load once up to temp.

The SAFC2 doesn't have internal/pre-built maps, it fudges the MAF signal to the ECU, reporting a lower load when set up to reduce fueling, hence the timing advancement issues.

They're good as a cheap sensor readout, not a lot else.

** Open loop