AFC Tuning Question

[mnetwork]

I have just bought my entire turbo package.... EVO316G, 680 injectors, afc, manifold, o2 housing, etc..... While waiting for it I am reading and reading every day trying to understand everything I can about tuning so it won't be as much of a project when I have to do it. Right now I am confused about Baseline Corrections... For bigger injectors you would put in a negative amount across the chart?? I don't understand this. To add more fuel you up the values.. but to start out with bigger injectors you make the values smaller than 0?? Wouldn't you put in positive values to add more fuel for bigger injectors?? Please have patience, I am brand new to to tuning and all that involves tuning...

 

[clipser-gs-t]

EVERY single car will be tuned differently with an s-afc. Your best bet will be to get it tuned on a dyno. I tinkered with mine for days with unsatisfying results, had it tuned on the dyno and couldn't believe the results. This is deffinatly not something you should try yourself, especially if you are asking this question.

 

[DSM_Zak]

I have an afc as well, if your using a MAF-T base tune with that for 680cc injector setting, then fine tune your car with the afc. Using the logger to read for knock, if you have knock, look at what RPM range and add fuel. but for your first drive log your car with the afc 0 across the board with the afc, but the maft set up for your injectors, add or take fuel ass need be as the logger tells you.

 

[mnetwork]

I'm am not using a maf-t.. I am using the stock sensor.. None of this answers my question anyway.. I am asking for an explanation of what I stated above...

 

[CanadianTSi]

The car doesn't know you just installed larger injectors, it thinks you have 450's so it opens them for the amount of time it thinks they need to be open to inject x amount of fuel, but since they are larger they flow more fuel in the same amount of time. By going into the negative you are making the car see less airflow therefore it thinks it needs less fuel and opens the injector for a shorter period of time.

 

[mnetwork]

Thank you for the explanation, I get it now totally. By the way.. what would you recommend for the as a baseline for the 680's??

 

[wvturbo2]

is ## car fwd or awd? either way as the other guy reccomended i would get the car dynoed n tuned with the s-afc. it still takes awhile to get it tuned to how u want on there. i cant imagine driving around the car guessing where to add fuel n where to pull fuel. but as fas a knock goes the s-afc2 reads knock. so i guess when it reads knock u can add fuel. but still this will take a very long time n im sure will never be right on, but good luck let us kno what u decide

 

[tom04841]

The safc doesn't read knock as it should, so dont put any faith into its reading.

You NEED to have a logger if you are going to tune yourself to monitor your fuel trims for base setting of injectors and to log timing to see if you are getting knock.

As far as your injectors go.....680 flow about 50% more than the stock 450. So i would set your lo throttle 1k setting to -40 and fine tune from there. This will probably still be rich.

You really need to do alot more reading before attempting to tune.

Here is a good thread: http://dsmtuners.com/forums/showthread.php?t=58403

 

[mnetwork]

This is the guide that I'm refering to, I have this printed out and I've been reading this in preperation for tuning. I also already have a logger in my car and I've been using it to get the feel of looking at ignition timing advance and fuel trims...

 

[CanadianTSi]

If you have a logger just follow the guide posted above.

As far as having to have your S-AFC tuned on the dyno, my car has never once been Dyno tuned, just a 20 minute tune with the logger.

 

[mnetwork]

Yeah, I want to learn how to tune myself.. it'll save money and make it easier to make changes when I need them. I also like learning how to do things on my own so...