What (electronically) does S-AFC do?
#1
SCCA Rookie
Thread Starter
Join Date: May 2001
Location: Sterling Heights, MI
Posts: 1,936
Likes: 0
Received 0 Likes
on
0 Posts
What (electronically) does S-AFC do?
If an S-AFC only changes the voltage going into the ECU from the Air flow sensor, then couldn't the same effect be done with a simple set of resistors and maybe a small circuit?
Like if I have stock 4x550cc injectors and put in 4x720cc injectors, couldn't I just change the voltage by a certain percentage and have it compensate appropriately for the bigger injectors?
Like if I have stock 4x550cc injectors and put in 4x720cc injectors, couldn't I just change the voltage by a certain percentage and have it compensate appropriately for the bigger injectors?
#2
Is that thing Turbo?
Join Date: Jan 2004
Location: Maryland
Posts: 1,411
Likes: 0
Received 0 Likes
on
0 Posts
The SAFC alows you to have different setting for each rmp. It take in a RPM signal and the AFM signal allong with otheres and then you can have your car tuned so its gettin the right amount of gas at every rpm, for example many NA run rich up high but lean or perfect in low rpm a resistor would step up or down the fuel at all rpms fixing some ranges while ruining others
#3
Locust of the apocalypse
Join Date: Apr 2003
Location: Directly above the center of the earth (York, PA)
Posts: 2,553
Likes: 0
Received 1 Like
on
1 Post
well,,, yes,,, but... DONT EVEN BOTHER...
the S-AFC allows you to alter the voltage by RPM or boost levels depending on how you hook it up...
a resister is a static (unchangeable) device.. one you put it in.. thats it...
Most cars require fuel to be added here and taken out there..... you can't do that with a resistor..
think about it... if you could just slap a resistor on.. every cheap *** on the forum, including myself would be doing it.
the S-AFC allows you to alter the voltage by RPM or boost levels depending on how you hook it up...
a resister is a static (unchangeable) device.. one you put it in.. thats it...
Most cars require fuel to be added here and taken out there..... you can't do that with a resistor..
think about it... if you could just slap a resistor on.. every cheap *** on the forum, including myself would be doing it.
#5
SCCA Rookie
Thread Starter
Join Date: May 2001
Location: Sterling Heights, MI
Posts: 1,936
Likes: 0
Received 0 Likes
on
0 Posts
I understand it's adjustable, I'm just wondering what it does to the airflow signal going into the ECU. If I can compensate it properly so that the car runs right with 4 720's, and still can handle enough fuel (because of the bigger injectors, pump, etc..) at 7000 RPM @ 10-12 lbs boost with a T04E, and not have to spend the dough on an S-AFC, then I'd love to do it.
#7
Is that thing Turbo?
Join Date: Jan 2004
Location: Maryland
Posts: 1,411
Likes: 0
Received 0 Likes
on
0 Posts
i think what it does that can't be done manualy is send different voltages to the ecu based on rpm like minus .1 volts here and plus .3 volts there, ("here" and "there" being differnt rpms)
Trending Topics
#8
casio isn't here.
Join Date: Sep 2002
Location: Greenpoint, Brooklyn
Posts: 3,332
Likes: 0
Received 0 Likes
on
0 Posts
of course once its set it cant be really changed (in the sense that you dont wanna sit and turn a **** while driving), but a potentiometer can change voltage outputs (as opposed to the resistor idea). if you needed less or more all the way through, that could possibly ideally work. but, as we know, its never that easy.
and for what its worth, i have no idea *exactly* how one works. wish i knew how it read and changed all voltages variable-pending. neat little things, arent they. i wonder how difficult their brain really is. no smarter than a flashlight and a can of cashews i bet. some people on this forum are digging out the brains of factory ecu's, but no one has disected an s-afc??
and for what its worth, i have no idea *exactly* how one works. wish i knew how it read and changed all voltages variable-pending. neat little things, arent they. i wonder how difficult their brain really is. no smarter than a flashlight and a can of cashews i bet. some people on this forum are digging out the brains of factory ecu's, but no one has disected an s-afc??
#9
SCCA Rookie
Thread Starter
Join Date: May 2001
Location: Sterling Heights, MI
Posts: 1,936
Likes: 0
Received 0 Likes
on
0 Posts
I dunno I bet some Honda guy has taken one apart...
I'm really wondering if this can be done, either a potentiometer or resistor or some sort of cheap-o circuit...
I'm really wondering if this can be done, either a potentiometer or resistor or some sort of cheap-o circuit...
#10
Engine, Not Motor
iTrader: (1)
Join Date: Feb 2001
Location: London, Ontario, Canada
Posts: 29,789
Likes: 0
Received 108 Likes
on
91 Posts
The S-AFC basically contains an ADC and a DAC controlled via a microcontroller. The controller reads the input voltage (from the AFM) using the ADC, does it's thing, then outputs via the DAC. Not fundamentally difficult in itself. The fancyness is the display and all the various RPM points...It is very easy to build a basic circuit and program a microcontroller for static corrections, but retuning means re-programming the controller. Unless of course you put the "map" on an EEPROM. Simple for anyone with a little electronics experience. But no one wants to tweak values in an EEPROM. People want to do it on the road, in real time, with a fancy dislplay...hence why no one has made a cheap knock off...
#14
SCCA Rookie
Thread Starter
Join Date: May 2001
Location: Sterling Heights, MI
Posts: 1,936
Likes: 0
Received 0 Likes
on
0 Posts
cause if I've got the injectors and all I'm doing is going to bigger injectors to provide enough fuel, and I know for sure what I'm doing (which I don't yet), then why not pay five bucks to make a cheap circuit?
#16
I'm a boost creep...
Join Date: Jan 2002
Location: Auckland, New Zealand
Posts: 15,608
Likes: 0
Received 8 Likes
on
8 Posts
Originally posted by Aaron Cake
...hence why no one has made a cheap knock off...
...hence why no one has made a cheap knock off...
Thread
Thread Starter
Forum
Replies
Last Post
Adaptronic MTX-L to adaptronic question
TeamRuffRacing
Adaptronic Engine Mgmt - AUS
1
09-30-15 08:13 PM