guys save your car and read this if your new to the afc
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guys save your car and read this if your new to the afc
well first off congrats on your new afc, it is a valuable tool in your quest to get more power out of your evo but it can also be your cars worst nightmare. that said i would strongly recomend purchasing a wide band o2 (shows you in real time your exact air fuel ratio) and an egt (shows you your exact cylinder temps). with out these two important gauges you are realy guesing and that can blow your motor up real fast.
now i have seen alot of people ask whats the differance between a reagular or narow band o2 and a wide band o2 or UEGO. well the differance is a narow band o2 can not replicate the same results within 1. afr accurately witch in some cases is ok but in our cars at 19-21 psi is not. the line we are trying to tune to is to fine and going into the 12.0+ range can spell disaster. now the wide band on the other hand can replicate down to .2 afr quite accurately witch is much better for us seeing as the line between reliability and power lays around 11.0-11.2 on 93 and 10.6-10.8 for 91 in my opinion (some will say as high as 11.8 on 93).
ok now with the egt. the egt gauge (exhaust gas temperature) also gives us veary important feed back in the tunning process. just as with the afr target being 11.0-11.2 we dont want our egt's going over 900 celsius, realy bad things start to happen over that temp so dont exceed that ever! back in the old days before wide bands wher popular we used the egt's to calculate afr's witch you dont need it for if you have a wide band but it is still good to have seeing as we will be getting real close to the 900 limit. for instance lets say you are running you car at WOT (wide open throtle) and you all of a sudden see your egt jump to 920 and your afr dive into the 10.'s, your ECU has seen something it doesent like. probably knock in this case witch = detonation and the ecu is pulling timing and throwing more fuel at the problem to try to save the motor from killing its self. now without the egt gauge there you would have only seen the afr change and had no idea how critical the situation really was. ( on a side note alot of guys like to use a data logging device witch works well also in showing timing but its hard to look at a logger and drive at the same time. its all personal preferance between the two.)
ok now we can get to the fun stuff. the way your afc works is by interupting the signal comming from your karmen sensor (thats what our cars use to gauge the air comming into the engine) going into your ECU. in doing that you can make the ECU see less air than whats really comming in, there for making it run leaner or vise vursa. this alows you to make adjustments to increase your power by hitting that afr of 11.0-11.2 we talked about. another great thing is the afc rather than a reflash can be adjusted any time, any where regardless of what new mods you have on the car (within reason).
now lets get that thing going shall we. once you have the afc wired into the car youll need to set it to karmen 4cyl with the arow pointing to the top right corner. youll also want the low high throtle points set at low 30%,high 70%. let me explain how to get these set.
ok in the main menu when you turn the ignition on (dont start it just have the key in the on position) use the center clicker and nob on the afc to select the bottom #3 etc. ok now click once over to the right, that will get you to the next menu. once there click right once on #1 sensor type. scroll down to karman. now that you have it on karmen back out of that menu by clicking left once(im not going to tell you how to click any more, im sure you get the idea by now). now you will need to select #2 car select (this is still in the etc menu). once you get into car select, change the number on the left to 4 cyl ( do this by turning the outer nob on the face of the afc). once you have the number 4 showing change the arow on the right so that it is pointing to the uper right of the afc display. thats it we are done in the etc menu of the afc.
ok now youll need to back all the way out to the main menu and scroll down to #2 settings. once in the settings menu scroll down to #3 TH-Point. once in the TH-Point menu change the number on the left or LO to 30% and the number on the right or HI to 70%. thats it we are all done setting up the basics of your afc. you can back up to the settings menu and start the car.
now if you start the car and it runs the same as it did before the afc you did it right. if you start the car and it runs and idles like crap double check the settings we have just gone through. if all of this checks out then you need to go back through the wire's and make sure they are all conected corectly.
now onto tuning the thing. as i said in the begining of this i cant tell you enough how important it is to have a wide band o2 and a egt gauge at this point but i know some of you dont and i will adress tunning for you also. in the settings menu #1 will be high TH-Point, thats what we are going to be dealing with. go ahead and select it. now once your in the high throtle map its going to look like a flat line running from left to right in the middle of you screen. now if you turn the nob left to right bars are going to apear going above or below that center line. this is the afc showing you what map and -/+ value you are inputing for that specific rpm range. being as our cars run rich from the factory we are going to be pulling some fuel out, so the fuel curve will more than likely be below that center line when you are done. if you have a wide band o2 at this point i would say go ahead and do a third gear WOT pull from about 2.5k rpm all the way to redline. you should notice the afr gets really rich after about 5.5k. you might also notice it gets real close to that 11.0-11.2 afr reading around 3k-4.5k. if you go over 11.0-11.2 afr go ahead and add some fuel back in. now if the car jumps up to anything over 11.8 at any point abort the pull immediately and add more fuel to that rpm range before continuing tuning. also keep an eye on those egt's, as i said earlier if the egt goes over 900 celsius abort the pull as this is a sign of detonation and add more fuel before continuing. now that you have done your first pull with the map at 0-/+ go ahead and start pulling fuel untill you get a smooth steady 11.0-11.2 afr reading all the way through the rpm to redline. remember if you are below 11.0 in the 10.'s that is fine, better to be safe than sorry.
now for some base lines i had when i was running light mods (tbe, mbc, intake, afc, and the gauges). with these mods and stock fuel pump my curve looked like this, this is also the limit i would recomend to anyone without wide band and egt (if you hit fuel cut this is your ECU's last ditch efort to potect the car from blowing the engine).
1,000-3,000 rpm 0-/+
3,500-4,200 rpm +1
4,800-5,300 rpm -2
5,900-6,500 rpm -6
6,500 and up -6 to redline
this is a veary conservative tune and there is a good chance you might be able to push it a bit, but without the right gauges you will never know.
ok after all the same mods listed above and a fuel pump the curve looked like this
1,000-3,000 rpm -2
3,500-4,200 rpm -2
4,800-5,300 rpm -5
5,900-6,500 rpm -9
6,500 and up -9 to redline
this was also a conservative tune but it worked well for me and should serve as a good starting point for you to tune off of.
i hope this answers most of you questions about the afc and gets you started in the right direction with it. your cor -/+ values may varry from mine but as long as you got the gauges and can see what your car is doing you should be ok. also worth note is that limits on you afr change with octain and quality of fuel. you can run a higher afr with 100 octain rather than 91 octain therfore making more power. this is when that egt realy comes into play. remember 900 celsius never changes no mater what the octain, so keep an eye on that. also in closing dont worrie about the low throtle setting untill you really start getting serouse about tunning. you need bigger injectors before that becomes a real issue. alright guys good luck with your new toy and remeber safer is better than 10 more hp and blowing up.
now i have seen alot of people ask whats the differance between a reagular or narow band o2 and a wide band o2 or UEGO. well the differance is a narow band o2 can not replicate the same results within 1. afr accurately witch in some cases is ok but in our cars at 19-21 psi is not. the line we are trying to tune to is to fine and going into the 12.0+ range can spell disaster. now the wide band on the other hand can replicate down to .2 afr quite accurately witch is much better for us seeing as the line between reliability and power lays around 11.0-11.2 on 93 and 10.6-10.8 for 91 in my opinion (some will say as high as 11.8 on 93).
ok now with the egt. the egt gauge (exhaust gas temperature) also gives us veary important feed back in the tunning process. just as with the afr target being 11.0-11.2 we dont want our egt's going over 900 celsius, realy bad things start to happen over that temp so dont exceed that ever! back in the old days before wide bands wher popular we used the egt's to calculate afr's witch you dont need it for if you have a wide band but it is still good to have seeing as we will be getting real close to the 900 limit. for instance lets say you are running you car at WOT (wide open throtle) and you all of a sudden see your egt jump to 920 and your afr dive into the 10.'s, your ECU has seen something it doesent like. probably knock in this case witch = detonation and the ecu is pulling timing and throwing more fuel at the problem to try to save the motor from killing its self. now without the egt gauge there you would have only seen the afr change and had no idea how critical the situation really was. ( on a side note alot of guys like to use a data logging device witch works well also in showing timing but its hard to look at a logger and drive at the same time. its all personal preferance between the two.)
ok now we can get to the fun stuff. the way your afc works is by interupting the signal comming from your karmen sensor (thats what our cars use to gauge the air comming into the engine) going into your ECU. in doing that you can make the ECU see less air than whats really comming in, there for making it run leaner or vise vursa. this alows you to make adjustments to increase your power by hitting that afr of 11.0-11.2 we talked about. another great thing is the afc rather than a reflash can be adjusted any time, any where regardless of what new mods you have on the car (within reason).
now lets get that thing going shall we. once you have the afc wired into the car youll need to set it to karmen 4cyl with the arow pointing to the top right corner. youll also want the low high throtle points set at low 30%,high 70%. let me explain how to get these set.
ok in the main menu when you turn the ignition on (dont start it just have the key in the on position) use the center clicker and nob on the afc to select the bottom #3 etc. ok now click once over to the right, that will get you to the next menu. once there click right once on #1 sensor type. scroll down to karman. now that you have it on karmen back out of that menu by clicking left once(im not going to tell you how to click any more, im sure you get the idea by now). now you will need to select #2 car select (this is still in the etc menu). once you get into car select, change the number on the left to 4 cyl ( do this by turning the outer nob on the face of the afc). once you have the number 4 showing change the arow on the right so that it is pointing to the uper right of the afc display. thats it we are done in the etc menu of the afc.
ok now youll need to back all the way out to the main menu and scroll down to #2 settings. once in the settings menu scroll down to #3 TH-Point. once in the TH-Point menu change the number on the left or LO to 30% and the number on the right or HI to 70%. thats it we are all done setting up the basics of your afc. you can back up to the settings menu and start the car.
now if you start the car and it runs the same as it did before the afc you did it right. if you start the car and it runs and idles like crap double check the settings we have just gone through. if all of this checks out then you need to go back through the wire's and make sure they are all conected corectly.
now onto tuning the thing. as i said in the begining of this i cant tell you enough how important it is to have a wide band o2 and a egt gauge at this point but i know some of you dont and i will adress tunning for you also. in the settings menu #1 will be high TH-Point, thats what we are going to be dealing with. go ahead and select it. now once your in the high throtle map its going to look like a flat line running from left to right in the middle of you screen. now if you turn the nob left to right bars are going to apear going above or below that center line. this is the afc showing you what map and -/+ value you are inputing for that specific rpm range. being as our cars run rich from the factory we are going to be pulling some fuel out, so the fuel curve will more than likely be below that center line when you are done. if you have a wide band o2 at this point i would say go ahead and do a third gear WOT pull from about 2.5k rpm all the way to redline. you should notice the afr gets really rich after about 5.5k. you might also notice it gets real close to that 11.0-11.2 afr reading around 3k-4.5k. if you go over 11.0-11.2 afr go ahead and add some fuel back in. now if the car jumps up to anything over 11.8 at any point abort the pull immediately and add more fuel to that rpm range before continuing tuning. also keep an eye on those egt's, as i said earlier if the egt goes over 900 celsius abort the pull as this is a sign of detonation and add more fuel before continuing. now that you have done your first pull with the map at 0-/+ go ahead and start pulling fuel untill you get a smooth steady 11.0-11.2 afr reading all the way through the rpm to redline. remember if you are below 11.0 in the 10.'s that is fine, better to be safe than sorry.
now for some base lines i had when i was running light mods (tbe, mbc, intake, afc, and the gauges). with these mods and stock fuel pump my curve looked like this, this is also the limit i would recomend to anyone without wide band and egt (if you hit fuel cut this is your ECU's last ditch efort to potect the car from blowing the engine).
1,000-3,000 rpm 0-/+
3,500-4,200 rpm +1
4,800-5,300 rpm -2
5,900-6,500 rpm -6
6,500 and up -6 to redline
this is a veary conservative tune and there is a good chance you might be able to push it a bit, but without the right gauges you will never know.
ok after all the same mods listed above and a fuel pump the curve looked like this
1,000-3,000 rpm -2
3,500-4,200 rpm -2
4,800-5,300 rpm -5
5,900-6,500 rpm -9
6,500 and up -9 to redline
this was also a conservative tune but it worked well for me and should serve as a good starting point for you to tune off of.
i hope this answers most of you questions about the afc and gets you started in the right direction with it. your cor -/+ values may varry from mine but as long as you got the gauges and can see what your car is doing you should be ok. also worth note is that limits on you afr change with octain and quality of fuel. you can run a higher afr with 100 octain rather than 91 octain therfore making more power. this is when that egt realy comes into play. remember 900 celsius never changes no mater what the octain, so keep an eye on that. also in closing dont worrie about the low throtle setting untill you really start getting serouse about tunning. you need bigger injectors before that becomes a real issue. alright guys good luck with your new toy and remeber safer is better than 10 more hp and blowing up.
Last edited by o4whtevors; Oct 25, 2005 at 07:57 PM.
Originally Posted by o4whtevors
np man i hope it helps you guys out.
Great stuff all around. This would be a good sticky, since it has just about everything people need to know in one place. I personally no longer recommend the S-AFC to anyone, because I just don't think most people are willing/able to do all the work required to tune it properly and safely.
Good write up. You never tune a device without some type of wideband 02 sensor reading the a/f ratio, otherwise you are just guessing. I learned to tune the original safc on a dyno when tuning my first car. Having the dyno tuner teach me what everything means really helped me understand what means what and the things you're suppose to look for.
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From: where the 2005 World Series Champions play
sticky this mods. great info. i thought i was going to be reading about a blown motor and how bad the safc is. what does a fuel cut feel like buy the way? never had it nor have i been in a car that has. does it feel like when you are turning and really low on fuel and the gas swishes to one side and kinda powers down and stutters?
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Joined: Oct 2004
Posts: 345
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From: where the 2005 World Series Champions play
btw here is the group buy for zeitronix dataloggers. you can get the lcd screen that will show you both egt ($100 extra but there is a GB for eclipses that will be cheaper, i haven't looked yet) and afrs on the same screen. plus ofcourse it has all normal datalogging features and you can use your labtop to view all fields at once if you don't want the screen. great buy for a great price.
https://www.evolutionm.net/forums/sh...48#post2285248
https://www.evolutionm.net/forums/sh...48#post2285248
Originally Posted by NapervilleEVO
sticky this mods. great info. i thought i was going to be reading about a blown motor and how bad the safc is. what does a fuel cut feel like buy the way? never had it nor have i been in a car that has. does it feel like when you are turning and really low on fuel and the gas swishes to one side and kinda powers down and stutters?
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Evolving Member
Joined: Nov 2004
Posts: 151
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Originally Posted by Warrtalon
What made you type all that out of the blue? I thought something bad happened and you were going to share a horror story, but it just ended up being a review of what we've already discussed so many times.
Great stuff all around. This would be a good sticky, since it has just about everything people need to know in one place. I personally no longer recommend the S-AFC to anyone, because I just don't think most people are willing/able to do all the work required to tune it properly and safely.
Great stuff all around. This would be a good sticky, since it has just about everything people need to know in one place. I personally no longer recommend the S-AFC to anyone, because I just don't think most people are willing/able to do all the work required to tune it properly and safely.
https://www.evolutionm.net/forums/sh...ad.php?t=30105.
Originally Posted by Ninj0x
Where do you have your EGT probe placed? I think for some configurations 900c is too conservative.
(temp in celcius x1.8)+32= temp in farenheit
1652 degrees farenheit... autometer gauges don't even read that high...
I would say with race fuel(pure race fuel) you could go a tad higher but just for a couple of seconds.