SC30096

so i went out tonight to street tune my SAFC. looking at the wideband i wanted to get AFR around 14 but the thing is I kept on taking out % but it seem to get richer so I began to add % and then It started to lean out... did I cross some wires or something?

TJohnson

Ummmm a few questions.

1. Are you doing full throttle tuning or driveability tuning? If you are doing full throttle tuning, you need to hand that over to someone who knows what they are doing because 14:1 is NOT what you want.

2. The AFC should just be tuned for those full throttle runs. The stock ECU can handle the driveability just fine. If you need to, you can make small adjustments here and there, but the stock ECU is pretty much going to control the cruising and partial throttle driving.

3. More than likely, you could have gotten the AFM signal wires backwards. I have never done that and wouldn't think the car would even run if you did that, but I guess anything is possible.

I've tuned countless cars on the AFC and have found this to be the best way to do it. Just tune it for the wide open throttle and let the stock ECU do the rest. If you can get the A/F around 11:1-11.5:1 on the street, you can be sure to be running at a great effeciency but not too close to the edge. That of course is for a turbo car though. You can go a bit leaner on a N/A motor.

Dx3

iTrader: (13)

^^^^ What he said...

14 is umm, very...safe

Jonny

SCoupe

Being rich is safe, in life and boosted engines.

About the S-AFC, my dyno tuned S-AFC2 has two setting that I can toggle between. One handles the fuel requirements of the EBC lower range settings (off -waste gate 10psi spring only, 12, 14 psi) and the other setting for 16psi.

The S-AFC2 piggy back overrides the fuel signal from the oem MKIV TT 6-speed ECU at all times, not just at wot, (TJohnson, I don't understand that part of your post or disagree with it). The fuel requirement of any BPU or APU turbo is higher than stock ecu is going to deliver and not just at WOT.

TJohnson

I didn't mean to generalize it if that's what you were thinking. On the AFM based cars, MK3 Supra, SC300, MKIV NA Supra, the stock ECU basically took over at partial throttle and normal driving. There was very little you could do w/ the AFC to change that. I never setup an AFC on a OBD2 car though, because by then, there were far better piggybacks and standalones out there, but on OBD1 cars, the stock ECU pretty much overtook the AFC regardless of what you put in.

SC30096

well I've already had a discussion prior to this about what AFR I should be looking for and a member told me for NA applications an AFR around 13.5- 14 is where any power would be gained.
https://www.clublexus.com/forums/sho...hlight=SAFC%2A
I also kept an eye on my knock sensor and everything seems to be in order. its still very strange though that the settings are reversed. so maybe I'll check my connections over again.

SC30096

problem found. turns out that some how I must have accidentally changed my sensor type to flap rather then the hotwire that it is suppose to be. all is well now.