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hi i have an 03 Civic EX with SAFC2 installed. some people told me the ECU will reset the SAFC2 settings after sometime making the adjustment / device useless. just in the case of some other piggybacks which eventually have no effect on our ECU. Claims 2003 - 04 ECU too intelligent for such devices to tap n re-route their signals.
Please advise. thanks.
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I have a hunch it might be. Someone else here said he could only add fuel up to a point, and then the ecu would correct it. Don't know what year car. I tried adjusting my vafcII up and down, and it's really hard to tell if there's a difference. I guess dyno is the only way to know for sure.
well its true that it does learn, altho it still will be affective for quite some time
just gotta road tune it... its much easier to do with an a/f gauge
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I believe the answer might be YES...i.e. Apexi's SV/AFC2 is useless on newer Honda ECUs.
Newer Honda engines i.e. D17A / K20A are controlled by CLOSED LOOP system. The engine uses four wires type of O2 sensor, the speed of feedback control time is quick. O2 sensor of 4wire type has built in heater, which can generate O2 signal immediately after engine start and low exhaust temperature at the time of an idling. It means O2 signal is available at all conditions.
This O2 signal can control fuel finely with realizing engine performance of more power and less fuel. It means automotive ECU becomes very clever. The clever ECU installed to vehicle after 2000 can detect the change of data immediately by Piggyback, Sub-computer (so called after market tuning ECU) which subsequent engine check lamp lighting, a rough idling, and the fuel adjusted by airflow, MAP sensor, additional injector, etc returns to the original A/F ratio immediately being unable to increase an engine output power and other various problems are incurred.
Hope this helps some people who's planning to install a S/VAFC2 in their 03+ model.
It's false, and this has been proven now. Someone dynoed their 03 civic with vafcII, aem intake, and race header. They spent 3+hrs on the dyno. At first the a/f curve was all over the place. When they were done, the ratio was almost a straight line and very close to the ideal value. He gained something like 5whp, so it obviously works. How do you guys think people here are tuning their turbos? People have the e-manage which can basically change everything from a/f to injector cycle to ignition timing with no probs.
It's false, and this has been proven now. Someone dynoed their 03 civic with vafcII, aem intake, and race header. They spent 3+hrs on the dyno. At first the a/f curve was all over the place. When they were done, the ratio was almost a straight line and very close to the ideal value. He gained something like 5whp, so it obviously works. How do you guys think people here are tuning their turbos? People have the e-manage which can basically change everything from a/f to injector cycle to ignition timing with no probs.
Actually its true. The O2 sensor (as mentioned above) does allow the ECU to try and maintain a "setpoint," in our case 14.7 A/F ratio. The only time this doesn't hold true is at WOT, where the ECU jumps to tables, which have hard-programmed A/F ratios.
You can dyno tune the partial throttle area of your car all you want - over time (not immediately, but eventually), the ECU will trim the fuel away because the O2 sensor is reading either more rich or lean (that's what the STFT - short term fuel trim, and LTFT - long term fuel trim, are for)....
Yes it sucks. This is why a lot of the guys at HT convert to either OBDI ECUs or run Hondata or Uberdata......
Well thanks for the info. That means dyno tuning the car with vafcii is completely useless. Wish I would've known before I spent $300 on a cool light box. I actually tried turning up the fuel a little on mine and was like wow this is good stuff, but then a week later I'm wondering what happened? So I turned off the corrections and it felt the same as stock. I guess that's why.
Did you go dyno a few weeks later to see if everything went back to stock?
bro you are not alone. couple of my buddies with S/Vafc2 are also facing the same problem. Their 03-04 Civics are reverting back to stock feel after like 1-2 weeks of pleasure. Initially they thought it's getting used to the power but apparently not.
those on e-manage might be lucky should the system able to outsmart the stock ECU. m still testing this product www.obitasia.com and will post my feedback when it's done. stay tune!
