Safc Hi/lo Q

[Highboost180SX]

So I am goin to put in my bigger injectors (525cc) and Z32 MAF and I am a little unsure about the HI/LO throttle settings on the SAFC. Should I monitor my daily driving and see what my max part throttle % is or is it pretty standard for the SR's? I would rather know how to figure out the setting than just a definite answer. I searched and couldnt find anything. Also, I have read on the forums that the SAFC "figures out" the settings in between the HI and LO settings. Can anyone shed light on this subject. I know there are a million and one posts on the AFC, I searched I promise.

Thanks in advance

[fliprayzin240sx]

Honestly, if you dont atleast have a wide-band, leave it alone and have professionals dyno tune the damn thing. Youll just end up screwing something up and itll either blow or itll never run right...

[NemeGuero]

like my car.

[Highboost180SX]

Honestly, if you dont atleast have a wide-band, leave it alone and have professionals dyno tune the damn thing. Youll just end up screwing something up and itll either blow or itll never run right...

I have a wideband and EGT with datalogging capabilities....

[NemeGuero]

Contact the manufacturer.

[JohnC]

The Hi\Lo is more then just the throttle point, as you posted.
The setting makes a huge difference.
You will want to use the formula for calculating what the actual
correction will be between the hi'\lo points. for this use apexi's formula
which I have put into a an excel spreadsheet for you. I am sure this will
clear things up for you. Change the Low & High Throttle Point % (yellow)
and their corresponding correction values (green) according to your desired settings.
change the throttle % to see correction for a set TP %.
****** The values in the file are not meant to be used. they are there just to fill in the formula *******
Correction Value Calculator (http://www.driftclub-il.com/johnc/technical/SafcCorrectionRatioCalculator.xls).
With this you can play with the settings and see the actuall values b4 making
changes.
I have followed this method to achieve very smooth, safe, and even economical "map".
15 AFR for highway, 11.5 for WOT on a S155bb and 555's. Now I have a pfc so no need for it
anymore.

[yokotas13]

wow that spreadsheet completely fucked my brain

[JohnC]

changed the file,
Might be easier to understand now :D

[yokotas13]

the wtf

whered youd get those values from?
http://img242.imageshack.us/img242/9215/untitledps4.png

[JohnC]

Those values are just to fill the equation, as I stated in my post.
You input whatever value you want to get the calculated correction value.
If you set LOW at 30% throttle (yellow) , put 30 in that field. If your correction value (green)
for LOW setting is 15 enter that value in the field.
Same for High.
Throttle Position Percentage is to enter the % at which your throttle will be.
All this info , enetred into the equation, will output the correction value
for the given throttle position percentage according the the values enterd
in the hi and low fields.

[yokotas13]

but how do you figure out what correction value you want/need?
thats what i cant figure out
are yuo doing this with a wideband or something

[JohnC]

but how do you figure out what correction value you want/need?
thats what i cant figure out
are yuo doing this with a wideband or something


That is the only way to do it right, using a WB.
For example: (with 555's , AGAIN THIS IS JUST AS AN EXAMPLE!!!)
Say you set the correction value for anything UP TO 30% TP (cruising )
on the highway
at -15%. Let suppose it gives you an AFR of 13.5. now you lower the correction
untill you get 14.7 AFR. easy.
The hard part is WOT. This should usually be tuned on the highest engine
loads, 4th gear or fifth is possible. Book some dyno time.
Now let assume that with no correction at above 70% throttle (hi TP value)
you get an AFR of 10.5. lower the correction value slightly untill you see
11's but I do suggest no more then 11.5. why? answer on next line :-).
Be aware that the way thge SAFC works is by lowering the signal from
the AFM to the ECU. That leads to more advanced ignition!!
Lowering the signal too much at WOT will cause bad things if KNOCK is present. get
someone that knows what to listen for. I strongly suggest to perform
the knock sensor calibration prior to tuning but DO NOT RELY on knock
signal.
Once you got the setting the way you want for HI and LO proceed
to using excel sheet. you will be able to see what the correction value
will be in every TP point in between the HI and LO. Moving HI and LO point
will affect the entire "map". You will have a good estimate on the AFRs you will
be running.

[yokotas13]

I was just making sure there wasnt a way to pull it out of your ass lol

I know how to tune it with a wideband and safc2, i was just making sure thre wasnt some weird SR thing im missing

[JohnC]

I was just making sure there wasnt a way to pull it out of your ass lol

I know how to tune it with a wideband and safc2, i was just making sure thre wasnt some weird SR thing im missing

Ya, no real secret that I am keeping to my self. ;)
I just found that using this excel cut down tuning times. I do not consider
my self to be a tuner but I have done a few of these for friends (2 years and counting)
and a couple of PFC equipped cars of my own.
The S14 will receive a professional tune later in the month once
the tuner from England arrives.

[Highboost180SX]

JohnC, you da man. This is exactly what i was searching for, thank you for the info in this matter. I will mess with it tomorrow and let you know how it goes. Thanks again

[steve shadows]

throw the afc in the trash and go BIKI ROM i heard it rocks lol

[JohnC]

happy to assist and please, be very very carefull.
As for the bikirom, I know it is a great solution but as with
everything it is a great solution when it works. I almost
went for a bikirom but after realizing that for me it will not
be as straight forward as getting a PFC. Terminology is a bit
different with the bikirom and setting it up, and starting to tune
with it is not as "easy" as it is with standalone systems. For more
or less a tuning newbie what is required is a easy to understand,
easy to install and easy to operate device.
Do not throw the SAFC in the trash just yet. For a modest 300hp
goal with slightly bigger injectors and maybe a bb turbo it will
do just fine!. There are thousands of people everywhere in the world
using it for these power levels and people are very happy with them.
At the end of the day, your car will only run as good as your tune is.
The first time I tuned a SAFC it was on my wrx with bigger inj and turbo.
I took it so easy that I wasnt done tuning it for an entire week doing two three
pulls (not on a dyno) after every change I made while making sure wideband readings
were consistent per throttle position I tuned. Take it slow, make sure you start
with a safe base. if you injectors are 25% bigger do not correct it by 25%
all through the range. Start at 10% or 15% as a tuning base. What I did to avoid
factory O2 correction to mess with my tune is I ran without it connected at all
and this way I was able to maintain my desired AFRs at cruising speeds and at idle.

[steve shadows]

happy to assist and please, be very very carefull.
As for the bikirom, I know it is a great solution but as with
everything it is a great solution when it works. I almost
went for a bikirom but after realizing that for me it will not
be as straight forward as getting a PFC. Terminology is a bit
different with the bikirom and setting it up, and starting to tune
with it is not as "easy" as it is with standalone systems. For more
or less a tuning newbie what is required is a easy to understand,
easy to install and easy to operate device.
Do not throw the SAFC in the trash just yet. For a modest 300hp
goal with slightly bigger injectors and maybe a bb turbo it will
do just fine!. There are thousands of people everywhere in the world
using it for these power levels and people are very happy with them.
At the end of the day, your car will only run as good as your tune is.
The first time I tuned a SAFC it was on my wrx with bigger inj and turbo.
I took it so easy that I wasnt done tuning it for an entire week doing two three
pulls (not on a dyno) after every change I made while making sure wideband readings
were consistent per throttle position I tuned. Take it slow, make sure you start
with a safe base. if you injectors are 25% bigger do not correct it by 25%
all through the range. Start at 10% or 15% as a tuning base. What I did to avoid
factory O2 correction to mess with my tune is I ran without it connected at all
and this way I was able to maintain my desired AFRs at cruising speeds and at idle.

I was being ardently facetious when i said bikirom...

get a haltech, best hp uprgade ther than turbo+injectors, and youll need the unit to tune for those first anyways.
plug and play bishes