SAFC II on 1jz, anyone tuned one themselves befor?

[tyottsoarer]

Hi all,

I'm running an SAFC II on a 1jz manual JZZ30 soarer with a GT3040 2jz injectors and some other goodies. I was just wondering if anyone has tuned one of these themselves?



I understand how they work and what they are doing to the engine; tricking the ecu into thinking it is running less boost so it uses less fuel. I also understand that this means it can be used to raise the boost cut on the stock ecu. But what i wanted to know was how this would affect the timing.

Also wondered if anyone has done a home job of tuning it. I've pulled some fuel out of mine, 15%, but its still running rich as hell on the A/F gauge. Also the transition (when the safc starts to mod the map signal) is very jerky at low throttle, does this have something to do with how i have set up the low/high throttle points? Am i better just taking it to a workshop have them remove the boost cut manually in the ecu and tuning the SAFC for $400 (this was quoted by hardcore performance in south east Queensland)

Any help would be great, thanks.

[camrygt?]

This sound like maybe full aftermarket managment would be better. I think SAFC's are more for standard injectors/light mods.
If you fool the ecu into thinking it is running less boost it will send in less fuel but also more timing so with a big turbo that may not be good at all.
I could be wrong but I don't think SAFC's are really designed to compensate for bigger injectors, more just for getting that extra 10% from your standard setup.

Wideband o2 gauge would be usefull, you can buy a techedge one for around $400 anyway and tune the fuel side of things easily and accurately enough on the road yourself.
But be careful of the timing.

[SilverGhost]

An SAFC intercepts the signal coming from whatever Air metering device you have (i.e. AFM, MAP, Karman vortex etc) and alters the signal so the ECU thinks the engine is getting more or less air and alters the injector duty cycle accordingly. This means by inputting settings into the device you can have your engine run richer or leaner in different RPM ranges. As a MAP sensor relates manifold pressure information to the ECU (including boost) it would fool the ECU by relaying whever reading you input.

I recommend getting a good dyno tuner to do it, unless you have a wideband sensor as camrygt said.

*Edited due to brain drama on my part *

[SilverGhost]

in addition an SAFC is a good device if you are running a fairly standard setup with say bigger injectors, or bigger AFM, but if you want a device that can take advantage of the hardware you have installed then a complete aftermarket ECU might be the way to go.

[tyottsoarer]

As far as my understanding is it intercepts the MAP sensor signal which messures posotive/negative (boost/vacuum) pressure in the intake manifold and in my case reduces the voltage being sent to the ecu by the sensor making the car think it is runing less boost and leaning it out and not adding fuel as camrygt? said.

Full managment is a hassel cause of the cost and the fact i would only really want to run a power fc which are hard to find for a JZZ30 soarer. Also I will be happy with the cars power as far as the SACF can take it (currently 350 rwhp without a proper tune) anythign above that is a bonus, the car is pretty fast as is just want it finished off.

[SilverGhost]

As far as my understanding is it intercepts the MAP sensor signal which messures posotive/negative (boost/vacuum) pressure in the intake manifold and in my case reduces the voltage being sent to the ecu by the sensor making the car think it is runing less boost and leaning it out and not adding fuel as camrygt? said.

Full managment is a hassel cause of the cost and the fact i would only really want to run a power fc which are hard to find for a JZZ30 soarer. Also I will be happy with the cars power as far as the SACF can take it (currently 350 rwhp without a proper tune) anythign above that is a bonus, the car is pretty fast as is just want it finished off.

Edited my previous post, you are correct

[nihilism]

I'd recommend getting a reputable workshop to dyno tune it for you. It could however be done on the street/track with the aid of a wideband o2 meter. $400 is way to much for just tuning an safc though should be able to get it done cheaper (should be well under 1hr dyno time).

[1200det]

As i understand a SAFC wont aid as a fuel cut defender

[chris davey]

Yes it will if you are leaning the engine out. Ie. 5v =14.7psi and boost cut. SAFC intercepts signal and holds it at say 4.9v or 14.4psi so the ecu is putting in fuel for 14.4psi and timing for that also. You may actually be running 16psi as the SAFC is rpm dependent AFAIK.

Also, here is the stock timing map for the 1jz. Basically, you are pretty safe with stock timing map and safc. It depends on what injectors, how much boost you are running and what fuel though. P18 is around 15psi and most likely where the timing will be if you are leaning it out. To check this accurately you could test the voltage coming out of the map sensor (i do this on my wideband o2) and then work out how much boost that equates to. 0v = -1bar, 5v = 1bar. Then you can go to this timing map and see how much timing it is running.



Alternatively, you could get a microleb and be 100% sure

[whatthe?]

Also, here is the stock timing map for the 1jz.

Sorry for O/T, but do you know where I can score this for a 7M? I'm running an SAFC and an SITC, it'd be nice to know at what rev range I should be retarding the timing @ 15PSI

[chris davey]

no idea mate. Was just luck that the 1jz one popped up somewhere.

[tyottsoarer]

Thanks Chris, as always the master of the 1j. I should be adding my time to your list once i get upto willobank