How hard is it to tune an AFC on my own?

[GSXpower]

I have all the supporting mods done on my 92 GSX, and now I am ready for the hard part... fuel tuning. I know that I will need to get a pocket logger, and a AFC, but I realy have no idea how easy that will be to tune. Are there good enough instructions that come with the AFC?, or isn't it something that I can do by myself. I was hopeing that I wouldn't need a dyno to tune it, and that the pocket logger would sufice. Any experienced input? Thanks.
Derek

 

[NewB2dsm]

First off what supporting mod you need for a afc? I guess wire cutters and soder? Also what are you "supporting mods" for your car?

you need something to view knock and timing and egts. So you need you pocket logger and either add fuel or take fuel out to get ride of knock and to give you better timing.

 

[leet]

Yes, you will need something to log how your car is running, so you know how to adjust your fuel trims.

 

[RipperXX]

If you know of someone that has a very similer mod list you could just put in there value's (only I would add a slight bit more fuel to be on the safe side) just to get it driveable and then tune from there.

 

[Bohrn]

first off you WILL need a logger of some sort. They are getting pretty damn cheap. Used cable, free software, used Palm, less than $100 US. Get one, you WILL use it, and it pays for itself first time you can find out and reset your CEL.

then its all about these links.

read on and learn it, practice, keep going. its a bit daunting at first, but you will get it.

http://www.vfaq.com/TMO/

http://www.vfaq.com/TMO/Tuning-Tips.htm

http://home.comcast.net/~tarryo/kyle/tuning.html

http://members.rogers.com/mrjackson9/FAQs/SAFC_Tuning.htm

http://www.hywell.org/plhelp/index.html

and some good maf therory if you want to read it. Good stuff to read before you get your logger. http://members.rogers.com/mrjackson9/MAF_Index.html

best of luck and have a good time

 

[DSMJim]

Another site that helped me was RRE's page. Check out http://www.roadraceengineering.com/ecltechtips.htm and their AFC settings and tips. That will give you a good idea how to adjust it.

 

[GSXpower]

Thanks for the links there, I will be studying that info extensively. What I meant by suporting mods are like full 3" exhaust, open filter w/2g MAS, and Dejon tool 3" intake pipe, FMIC with pipes, and boost controler and gauge. Those are my major ones. All of those mods will run without the need for an AFC. But, the stock injectors are a "choke point" Normally you are always trying to find ways to get more air into the engine to make more power, because the engine can always match the extra air with more fuel. Now I have my airflow mods, and once I add bigger injectors I will have to have an AFC to control them, because the factory ECU won't recognise them. I will be getting a pocket logger before I even get my 550 injectors, or my AFC. I just want to play around with it, and make sure I know how to use it before I try to adjust my ECU with my AFC. That is where I am coming from I guess. Thanks again

 

[Bohrn]

2gmaf might need an safc, it flows 20% more air(or so I've heard) than a 1g, and you will easily max out your stock injectors and pump. Hell the 1g maf will max them out

 

[CanadianTSi]

Your running a 2g MAF setup with no form of fuel control????

Does your car actaully run right??

 

[btrux06]

how are u running with just a 2g mas? u need 550s or afc and it riched up 20 percent to be able to run good with a 2g mas

 

[GSXpower]

I am running my 2g MAS the same way that a 2g does with no problem. They have the same stock injectors, and the same factory fuel control. The factory 450's can match fuel for a little more airflow than stock, they are not even close to floating yet. I have the screw on the bottom of the MAS turned in all the way so that helps out a bit. Let me remind you that I have a 250lph fuel pump, and I am upgrading to 550's and an AFC shortly. I appreciate you guy's concern for my car though, and I will tell you how it urns out.

 

[Cirus_93TSI]

i hate to tell you, but the ecu doeant have any way to make the 450s "match" the extra airflow of a 2g mas, the ecu can not tell the difference between a 1g and 2g mas

when u splice in a 2g mas it sends the same exact signal as the 1g mas, except it flows 20% more air whlle sending that same signal
what this means is that your ecu thinks your running a 1g mas, and the ecu will adudst the fuel based on how much air a 1g mas flows, but a 2g mas flown 20% more, so you are running 20% lean all the time

not that the car wolnt run like that, but your losing a considerable ammount of power, and running that lean isnt good for your engine

in short, your 450s are flowing the same exact ammount of fuel as they would with an unmodified 1g mas unless you have fuel control to compensate

 

[GSXpower]

The 1g MAS and the 2g MAS both measure the air the same way, it is just that the 2g MAS is larger in diameter, so it alows more air fo flow through it. This extra air is still being measured by the MAS, basically it is less restrictive than the 1g, that is all. Just like a K&N air filter flows 30% more air than the stock filter, does that mean that your car will be running 30% lean than before? The signal put out by the MAS is always changing depending on how much air your turbo is pulling through the intake pipe based on engine demand. All the air is still being measured by the 2g MAS, it is just getting through faster, flowing easier, alowing for better response and top end. Someone back me up if you see what I mean, or... correct me if I am wrong before my car blows up:thumbdown

 

[Bohrn]

K&N doesn't have any metering devices in it.

Lots of people have run 550's and a 2gmaf with no issues, that tells me that you need the extra fuel to run a 2g maf in a 1g car.

but here is the big one. What does your logger tell you? What are your fuel trims like? What does your 02 trim tell you when driving? What are your O2 volts? How is your knock count? how many degrees of timing? And the last 3 have to be measured at WOT for a full pull of 3rd gear(3grand to redline).

not saying it can't be possible, these cars have a way of making the impossible into the highly improbable. EG, I have never hit fuel cut. Each car is different so if your logger shows good numbers with your setup, good for you, cheaper setup for you

 

[DeathBeast]

This has been my experience:
-The car runs horribly lean with 2G MAS, 255 fuel pump, no tuning.
-You can compensate with 2G MAS, 255 pump, and AFC, but EGTs are still high. (Expecially on the freeway)
-Car runs really rich with 2G Mas, 255 fuel pump, 550s, no tuning.
-I'm trying to get it leaned out right now with the AFC, but I'm still learning too.

Thanx,
DeathBeast

 

[btrux06]

gsx power, u have no clue what ur talking about!!! u said your last past like u knew 100 percent that u were right with no doubt, but your wrong, the ecu will get a signal from the 2g mas but the signal will be 20 percent less than what the airflow actually is, so the mas will tell the ecu its getting say 2000 hertz but since the mas is bigger and calabrated differently the car is really getting 2500. its the same as installing 550 injectors, the ecu still thinks theres 450 in there, so when it sends a 50 percent duty cycle signal to the injectors and open half way your now getting 275 cc of fuel coming out instead of what the ecu thinks its putting out which is only 225. and how u compared it to a kn filter isnt really a good comparison. anyway your car may run ok for now, but its nowere near 100 percent tuned good like it should be, youll see, install 550s or get safc and your car will run a hell of a lot better. i dont know were u learned what u thought or who told u that but its way wrong.

 

[GSXpower]

I have the S-AFC on the way, either way I am just experimenting, and trying different combinations. I have heard a lot of different theories from different guys out there, and that is why I have a hard time believing someone's "theories". I did learn from brix06 that the 2g MAS is calibrated differently than the 1g MAS. That explains a lot, and would obviously make my last post incorect. Thanks for that bit of information, and to the other guys who gave me the links for tuning an AFC, and for not chewing me out for asking questions. That's what this forum is all about right? Thanks.

 

[btrux06]

i chewed u out causs u thought u knew what u were talking about, sorry it was just like u thought you were 100 percent right, u didnt ask, u asummed, if u would have asked it would have been all good , any way sorry good luck, just here to help,

 

[99gst_racer]

Here's a couple of links that might help you.

Install - http://www.prostreetonline.com/pso/pages/howto/showarticle.asp?articleid=25

Tuning - http://www.prostreetonline.com/pso/pages/howto/showarticle.asp?articleid=31