heres how you make the safc effective - Boost Forum

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heres how you make the safc effective
Tuesday, November 15, 2005 10:56 AM
ok i see alot of people talking about the safc and saying its abad thing to use. first off you dont use the safc to raise fuel pressure. you use an fmu for it and then the safc for fine tuning.

now heres whats going on withthe safc. you cant just add the safc and expect it to work witht he obd2. it wont. when you modify the settings form the map sensor, the o2 sensor picks up the change and the computer makes the neccesary changes to go back to what its been programmed to do. thats why some guys with piggy backs cant run an o2 sensor, same withthe safc. we noticed on the dyno withthe sniffer that after any changes the car would relearn. once we cut the wire for the o2 sensor everything cleaned up. the cel was on for a couple hours and has since gone away. we tuned the car withthe fmu and fine tuned with the safc to get about 11.2:1 across the chart. its right in that range and its holding that. the safc is nice to tune bigger injectors foridle and to open them up more or less under boost. anyone who says its a bad tunng tool is a moron, simple as that, or youve never run one and if you have then you didnt do it right.




parting out my built and boosted 97 z24 so4x4.com/cavy.html for pics and a parts list

Re: heres how you make the safc effective
Tuesday, November 15, 2005 10:58 AM
So if I remove my o2 sensor, it'll remove my P0107 MAP code?








Failure is not failure if you learn from it
Re: heres how you make the safc effective
Tuesday, November 15, 2005 11:08 AM
I can't see how that would work. The O2 sensor has nothing to do with the SAFC. By cutting the wire you are just removing the signal to the computer, and it will freak out, max out your fuel tables, and it'll run like @!#$. I know this because my car has been driving around for the past 3 weeks without an O2 sensor and I am using the SAFC. I could not get it to run correctly at all.





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Re: heres how you make the safc effective
Tuesday, November 15, 2005 11:10 AM
not sure what you did man but the guy that tuned my car said the same thing and we saw it on the screen, whenever the settings were changed the ecu would compensate. unhook the o2, car threw a light for a short while and then cleaned up. runs great now. wideband shows its runngin the same as when it was tuned.

his mechanic said that the o2 is used as a secondary source to adjust the air fuel ratio. unhooking the o2 and leaving it in free air is different than unhooking the wire from it. ive ha dno problems at all and the car runs great




parting out my built and boosted 97 z24 so4x4.com/cavy.html for pics and a parts list
Re: heres how you make the safc effective
Tuesday, November 15, 2005 12:04 PM
NO.

The O2 sensor is the primary source for a/f ratio adjustment when the computer is in closed loop mode. If you snipped the lead to your O2 and the CEL has since gone out, I think the bulb burned out. I don't know of any OBD2 computer that will run code free without a valid O2 sensor signal.







09:f9:11:02:9d:74:e3:5b:d8:41:56:c5:63

Re: heres how you make the safc effective
Tuesday, November 15, 2005 12:05 PM
your, his, their, whatever mechanic is an idiot. plain and simple. in a OBD2 car the O2 sensor is the PRIMARY A/F ratio control input. Does he think that the MAP can sense the A/F and adjust to it our something.

Someone needs to educate these "mechanics." Tell them to go take an ASE test and then call themselves a tech. I see a lot of bad info being spread by them.



I used to race cars, now I race myself.
5K PB: 24:50
10K PB: 54:26
Re: heres how you make the safc effective
Tuesday, November 15, 2005 12:38 PM
He's not saying cut the 02 sensor to the obd-II computer.

He's saying cut the 02 sensor option wire from the S-AFC II to the purple 02 sensor wire. People like to hook it up.

Apparently the OBD II is learning off of that connection from the S-AFC so he is saying to disconnect it and the computer will no longer be learning what the S-AFC is doing.

That is what he has explained to me. In a small way it makes sense.

-Chris-



-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
Re: heres how you make the safc effective
Tuesday, November 15, 2005 1:37 PM
I don't remember ever hooking my oxygen sensor to my safc...





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Re: heres how you make the safc effective
Tuesday, November 15, 2005 1:51 PM
JimmyZ wrote:NO.

The O2 sensor is the primary source for a/f ratio adjustment when the computer is in closed loop mode. If you snipped the lead to your O2 and the CEL has since gone out, I think the bulb burned out. I don't know of any OBD2 computer that will run code free without a valid O2 sensor signal.


This will probably be the only time I will agree with Jimmy on somthing. You need a O2 sensor hooked up. Also I have heard of many people running them on J's and working great.



FU Tuning



Re: heres how you make the safc effective
Tuesday, November 15, 2005 2:24 PM
don't you love when the completely clueless show their benevolence and decide to "educate" the rest of us poor slobs?




Arrival Blue 04 LS Sport
Eco
Turbo
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'Nuff said
Re: heres how you make the safc effective
Tuesday, November 15, 2005 2:43 PM
is he saying to leave it hooked up just in free air?

Quote:

judgez24 says

his mechanic said that the o2 is used as a secondary source to adjust the air fuel ratio. unhooking the o2 and leaving it in free air is different than unhooking the wire from it. ive ha dno problems at all and the car runs great



Thanx Charles

Re: heres how you make the safc effective
Tuesday, November 15, 2005 3:15 PM
Quote:

He's not saying cut the 02 sensor to the obd-II computer.He's saying cut the 02 sensor option wire from the S-AFC II to the purple 02 sensor wire. People like to hook it up.


That doesnt make sense either.When you disconnect that wire,it shouldnt throw a check engine light because that wire wasnt supposed to be there in the first place.


Peter
'06 Cobalt ss/sc W/G85 Package
Gm Stage II W/2.79" Pulley
K&N Drop In Filter
Custom Magnaflow Dual Exhaust

Re: heres how you make the safc effective
Tuesday, November 15, 2005 4:07 PM

If it is really running correctly and the computer is NOT throwing any codes, please explain exactl what you are doing a little better. I have never used an S-afc2.. but I have used.... oxygen sensors... I've used them enough to know what happens when you disconnect it from the stock computer.
I'm on AEM wideband and a Greddy Rebic III plus the sim. If there are better tuning options out there utilizing the stock computer I want to know.



Cardomain|Myspace

Re: heres how you make the safc effective
Tuesday, November 15, 2005 4:19 PM
I have the RSM reflash and my second o2 is deleted.. or so they say......... completely..... I am running on the primary o2 sensor only....... if you place the primary in the proper location on your dp you will get proper readings..........

too close and you'll burn em too far and they will read cooled exhaust gas.

Lee


JDM Civic Hatch
Status: Parting Out Turbo Kit....
14.224 @ 102.01MPH @ 5.5psi.... 2.3 60'
Next: Civic JDM B16a2 w/GSR LSD Turbo - Goal 300whp 1400lbs...
Re: heres how you make the safc effective
Tuesday, November 15, 2005 4:20 PM
Basically what he is saying is with the S-AFC hooked up with the optional 02 sensor wire to the 02 sensor..... apparently he was told that the stock computer "learns" through this connection...

SO the OBD-II starts to learn what the S-AFC has done and like the ecotec starts to counter these changes....

This is what he was told.

He disconnected this optional wire (I have it hooked up too) and he noticed that the car was taking the changes he was making to the S-AFC a LOT better.

That's ALL he is saying.

That and that the S-AFC is a good tool if you use it for what it's intended which is adjusting the fuel curve via RPM.... you still need an FMU to add fuel with boost.

*thumbsup*

-Chris-



-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
Re: heres how you make the safc effective
Tuesday, November 15, 2005 4:27 PM
Lee wrote:I have the RSM reflash and my second o2 is deleted.. or so they say......... completely..... I am running on the primary o2 sensor only....... if you place the primary in the proper location on your dp you will get proper readings..........

too close and you'll burn em too far and they will read cooled exhaust gas.

Lee


the stock O2 doesnt care how hot the gases are. the oxygen content is the same no matter where it reads from. the only thing that will hurt it is ultra high temps.

you could put it right before the cat and it would work fine



I used to race cars, now I race myself.
5K PB: 24:50
10K PB: 54:26
Re: heres how you make the safc effective
Tuesday, November 15, 2005 5:04 PM
really because I had it down like 2 feet from te turbo... car wouldn't run right...
moved it up.... maybe 5" from the turbo and it ran like @!#$ for like 2 days and I just kept resetting the ecu and it ran fine one time and was good ever since....

Lee


JDM Civic Hatch
Status: Parting Out Turbo Kit....
14.224 @ 102.01MPH @ 5.5psi.... 2.3 60'
Next: Civic JDM B16a2 w/GSR LSD Turbo - Goal 300whp 1400lbs...
Re: heres how you make the safc effective
Tuesday, November 15, 2005 6:34 PM
hypsy(the12secondone) wrote:
Lee wrote:I have the RSM reflash and my second o2 is deleted.. or so they say......... completely..... I am running on the primary o2 sensor only....... if you place the primary in the proper location on your dp you will get proper readings..........

too close and you'll burn em too far and they will read cooled exhaust gas.

Lee


the stock O2 doesnt care how hot the gases are. the oxygen content is the same no matter where it reads from. the only thing that will hurt it is ultra high temps.

you could put it right before the cat and it would work fine


Temp has alot to due with a 02, why do you think they come heated on some cars. It doesn't work unless its at the right temp. Never heard of open/closed loop, it has to do with the 02's temp.



Re: heres how you make the safc effective
Tuesday, November 15, 2005 6:53 PM
Quote:


Never heard of open/closed loop, it has to do with the 02's temp.


No it doesn't. It IS true that the ECU won't go into closed loop operation until the O2 sensor is up to temperature BUT the open/closed loop operation is not solely dependant on the temperature of the O2 sensor.

There are 5 modes of operation, not just Open/Closed loop:

1. Open Loop due to warm up condition
2. Closed loop using oxygen sensor to control fuel delivery, seen after sensor is warm.
3. Closed loop due to driving condition such as acceleration or deceleration.
4. Open loop due to a system fault (bad sensor, other check engine code)
5. Closed loop using at least one oxygen sensor, but with a fault, which may indicate use of a single sensor for feedback. This is normally not seen in a single bank vehicle setup.





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Re: heres how you make the safc effective
Tuesday, November 15, 2005 6:55 PM
Sorry, #2 should read:

2. Open loop using oxygen sensor to control fuel delivery, seen after sensor is warm.



4cyltuner.com - Information Source For 4 Cylinder Tuners
Buy stuff from CarCustoms Ebay! Won't be disappointed!

Re: heres how you make the safc effective
Tuesday, November 15, 2005 7:09 PM
okay if what your saying is true my car was staying in open loop too long because the 02 sensor was too far away and thus not getting hot enough EVER to make the ecu realize it's warm and ready for closed loop.... so temp does matter ????

Lee


JDM Civic Hatch
Status: Parting Out Turbo Kit....
14.224 @ 102.01MPH @ 5.5psi.... 2.3 60'
Next: Civic JDM B16a2 w/GSR LSD Turbo - Goal 300whp 1400lbs...

Re: heres how you make the safc effective
Tuesday, November 15, 2005 7:16 PM
SPDDMON wrote:
hypsy(the12secondone) wrote:
Lee wrote:I have the RSM reflash and my second o2 is deleted.. or so they say......... completely..... I am running on the primary o2 sensor only....... if you place the primary in the proper location on your dp you will get proper readings..........

too close and you'll burn em too far and they will read cooled exhaust gas.

Lee


the stock O2 doesnt care how hot the gases are. the oxygen content is the same no matter where it reads from. the only thing that will hurt it is ultra high temps.

you could put it right before the cat and it would work fine


Temp has alot to due with a 02, why do you think they come heated on some cars. It doesn't work unless its at the right temp. Never heard of open/closed loop, it has to do with the 02's temp.


ok you wanna say im wrong...now i point out where your wrong. loop has NOTHING to do with exhaust gas temperature. ZERO! it has everything to do with SENSOR temperature. thats why theres a heater. An O2 sensor doesnt read effectively until its at 600F. The sensor couldnt care less if the gas was 2F or 200F. it only cares about the sensor.

and trust me...i know PLENTY about the loop operations. I also know some things that you don't. I guarantee it. Shifted knows what I know...I'm sure of it because I told him He probably knows more but he atleast knows what I know



I used to race cars, now I race myself.
5K PB: 24:50
10K PB: 54:26
Re: heres how you make the safc effective
Tuesday, November 15, 2005 7:21 PM
Way to totally change the topic of this post, guys.

-Chris-



-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
Re: heres how you make the safc effective
Tuesday, November 15, 2005 7:26 PM
hypsy(the12secondone) wrote:thats why theres a heater. An O2 sensor doesnt read effectively until its at 600F. The sensor couldnt care less if the gas was 2F or 200F. it only cares about the sensor.


ummmmmmm NOT HEATED primary o2 SENSOR ..... I was thinking about COVERTING it to a HEATED 4 wire from my 2 wire not heated.... so my car could get into closed loop faster.........

not saying your wrong...............just saying that temp does have something to do with it ....

Lee


JDM Civic Hatch
Status: Parting Out Turbo Kit....
14.224 @ 102.01MPH @ 5.5psi.... 2.3 60'
Next: Civic JDM B16a2 w/GSR LSD Turbo - Goal 300whp 1400lbs...
Re: heres how you make the safc effective
Tuesday, November 15, 2005 7:28 PM
I drive an 01 2200 cavalier.... not a heated o2 sensor up front.... so if it was too far away ..... it couldn't get to 600F then what would happen.... my car would run in open loop ????

Lee


JDM Civic Hatch
Status: Parting Out Turbo Kit....
14.224 @ 102.01MPH @ 5.5psi.... 2.3 60'
Next: Civic JDM B16a2 w/GSR LSD Turbo - Goal 300whp 1400lbs...
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