Apex~i SAFC (II) Discussion/Help Thread

[terboneon]

Hey Guys,
Just had a quick question about an s-afc install in a 2004 srt-4. I've completely installed the unit with the msd tach driver and tested the car out. The rpms matched up perfectly, but a check engine light was triggered, and the car would not idle.
I then removed the three wires (input, output, and tps) from the map wire on the ecu and reconnected the two cut ends. With this setup, the car ran perfectly and the revs still matched up perfectly.
Do you have any idea what the problem might be? I've set the sensor type to pressure, 10 in, 10 out, 4 cyl. I've had this unit on my eclipse before, and it worked flawlessly, I'm scratching my head on this one.
Any help is greatly appreciated.
-Matt

[funks]

terboneon - what was the code that it threw?

for other SAFC users, how are you guys calibrating the SAFC so that it sets up the proper scale for MAP sensor (instead of the TPS)..

It's kinda hard to make the TPS sweep from low to high when you want it to - lol..

I guess the only way one can have a nice proper scale for the MAP voltage is if one were to hook up the GRAY wire to a voltage regulator, run the TPS calibration then have the voltage regulator sweep from .18 v -> 4.82 volts. Then hook up the wire back to the MAP sensor again..

with the default UP setting on the Throttle Sensor Type

Closed = 0 -> 1 v
Fully Open = 3 -> 5v

considering one can't properly calibrate the range, the SAFC will most likely show 100% by 3v (or around 6.04 psi).

Hence the high and low settings should be set capped at the value of 3v for 100% (instead of 4.83 for 100%)

Setting the hi throttle to 90% will mean 2.7 volts (or around 4.07 psi), and setting the low throttle to 10% will mean .3 volts (or around -11 psi)..

G

[2004SRT-4]

Quote: Originally Posted by RoostBoost

I just want to make sure....with bigger injectors/fuel pump, and/or return line I won't need a map clamp to run 20+ psi of boost??

NIVO did you have an adapter or something for a return line that we would need??
Thanks!!

Anybody???

[im4u2nv81]

Everyone is saying you only cut one wire when installing the SAFC.
I did my install yesterday. I "tried" to cut two wires. One of course is the wire going to the tach for the tach adaptor. The other was the MAP wire (dark green and red I think?). I cut that wire, hooked up the wires as Pap's diagram shows and it would not idle for shit. It would go way rich at idle and then way lean as soon as I touched the accelerator. My connections may have been bad but was I wrong to cut those wires?
Like someone else said, I put the wire back together and it ran fine after that. But, aren't you supposed to cut that wire so the SAFC actually alters the signal before it goes back to the PCM? I'm pretty sure thats whats going on. If you leave it connected and just tap into the wire then the SAFC really doesnt have a chance to alter the signal, correct?

[ACRucrazy]

*thinking out loud*
Id think with 13 pages we would have coverd every aspect of a SAFC install on the SRT, 4 times over. Id hate to see what its like when the AEM EMS is released.
*thinking out loud*

[im4u2nv81]

I agree with you and I know it's been beaten with the ugly stick.

However, I am having trouble with my install. Before I continue to mess things up, I am asking the "educated" people who know what they are doing moreso than me, what am I doing wrong, what should I do different. If you really don't have a contribution, your single post, only added to the confusion.

Thanks, but no thanks.

Now, 2 posts up from this one...can someone help a guy out?

[sour kraut]

I used a gm 3bar sensor to get a signal(just the tps) to run my safc. When I went to calibrate my tps voltages, I put it to low and grounded my wire, then put it to high and connected it to the 5v supply for the map sensor I added. The last thing I did was then soildered(?) the wire to the signal out on the 3bar. Now I'm able to ajust my high low just by using basic % formulas. 0psi=1.62volts; 1volt=App:9.12psi yadda,yadda,yadda. You get the picture. I also use the 3bar signal with my wideband so I can datalog actual boost even if it is over 18.5psi. Really no good info in my post, but I was bored!

[Brian87gt]

I've had the safc on my car for quite a while, and it's worked greaat. However I recently added 750 cc injectors, and an agp 50 trim. I have every mod except cams and headwork. The problem is I'm only at 20 psi, and am only able to pull 2-4% fuel from 5500 on up, I could be wrong, but that just sounds wrong. I was told I should be pulling much more fuel than that. Any suggestions

[funks]

how about a fuel pump?

if you add a return fuel kit, you'll have more than enough fue..

I'd pull at least 4%, else you'll run into the boost limiter cut (if you have S1)..

[Specialk43]

So now that I understand, the S-afc will not do anything between low and high throttle settings. So you can tune for anything under -11psi if low throttle is set at 10%, and if you set the high throttle at 90% or 4.07 psi, then you can lean out the fuel. But it will not do anything between 10%-90% correct? The factory ecu, or stage one in my case would control everything.

[sour kraut]

No! read the manual!! The safc will look at the percentage of throttle that is coming into it and calculate the amount of fuel for that percentage using the low and high settings.

[NEASport]

what do you have is everyone setting the NE points at(like comes or changing them) and what percentages are people using for high and low throttle?

[hydrohopper]

Hate to break up the intersting subject that is going on here but got a question . . .
Here is what I am seeing. SRT with a EBC and the SAFCII. Before you install the SAFCII the boost on the EBC is set at say 15 psi. When you go to intall the SAFCII you base all your readings from your set 15 psi. But a few days later you decide to knock up boost to about 20 psi. Do you have to go back through and change all the readings again on the SAFCII?

[toyoguru]

yeah, for more boost, you will have to re-tune...it just wont take as long as you should already have the NE-points plotted out where you need em...pretty much just giving a little more fuel back to even things out with the higher boost...assuming you have enough fuel system to keep up with more than a 20psi demand.


For the question above....the safc utilizes the hi and lo settings..and calculates the needed correction using a complicated algorhythm or something like that...

NE points will be decided on where you need to make fuel adjustments...I usually go with about 400 rpm increments..but where the boost starts to come in, I have 3 NE points set pretty close to allow for a finer adjusment and help keep the a/f ratio smooth as I can, of course some will be further away from 400rpms..its just tuning it out til you get things where the a/f ratio is smooth...its going to differ between cars depending on fuel system, boost, type of turbo, etc..

[-ND4SPD-]

Quote: Originally Posted by Sour Kraut

I used a gm 3bar sensor to get a signal(just the tps) to run my safc. When I went to calibrate my tps voltages, I put it to low and grounded my wire, then put it to high and connected it to the 5v supply for the map sensor I added. The last thing I did was then soildered(?) the wire to the signal out on the 3bar. Now I'm able to ajust my high low just by using basic % formulas. 0psi=1.62volts; 1volt=App:9.12psi yadda,yadda,yadda. You get the picture. I also use the 3bar signal with my wideband so I can datalog actual boost even if it is over 18.5psi. Really no good info in my post, but I was bored!

So am I understanding this correctly? You are using the TPS instead of the MAP. You've calibrated the TPS voltages on the AFC to read to 3 bar now. You can now read boost above 18.5psi. Hmmm... am I the only one who thinks this is pretty cool? Lets further discuss.