I recently bought my evo and have been investigating just exactly what i got. Among them is the S-AFCII...

I understand that this is an "APEXi Super High Airflow Converter", but i guess i just need a little understanding of exactly how it works and how to operate it. I have the manual, and i have been looking at it on and off for days, but it is stil chinese to me . There is an LED controller with a dial and some other buttons in the glove compartment, and I had one of my more knowledgeable friends look at it. He fiddled around, looking at the settings and just said "The way it is tuned you are playing it safe...you could probably get more power out of it."

My 2003 Evo 8 also has a custom exhaust (not sure by who), and the catalytic converter has been removed. I would assume that with the S-AFCII, the Evo was designed to take in air like an olympic swimmer . But what kind of additional horsepower does that equate to?

 

Not the answer you asked for, but that is old technology. Your best bet is removal of the safc and visit the ecuflash forum to get familiar with the stock ecu and what it can do and have your car tuned or learn to tune.

 

Don't quote me on this, but I'm pretty sure you can do everything the S-AFC can do (and a lot lot more) with a simple tune.

My advice would be to take your car to a tuner near you (AMS in Chicago, Mellon in Memphis, etc) and have them tune your car. They will probably tell you to trash it, though.

 

as he said AFC is for older cars to tune air-fuel ratios as older ecus were difficult to adjust fuel and timing maps. often you had to solder new chip which had adjusted fuel/timing map but thats only base map, then you fine tuned it with AFC. this is caveman way considering evo ecu is superior to most piggyback controllers on the market, only thing beating it is true standalones.

 

ok how much does a new ECU tune/flash run me? And is the S-AFCII damaging at all, or just outdated? If i plan to further mod the car then i will certainly get rid of the S-AFCII

 

Just outdated. Tunes usually run around $300-$400, but come with dyno time, dyno graphs, as well as getting your car looked over by someone that is very familiar with Evos. Well worth the money in my opinion.

Or you can get an e-mail tune which is cheaper, but you have to KNOW that your motor is in good working condition (no leaks, good compression, etc.) and will need a cable, laptop, scanning software to complete.

Either way, I would bet you money your car is faster and more drivable after.

 

BLAMExTHExLAG as mentioned the S-AFC is a piggy back computer that basically molests the airflow value in order to trick the ecu into thinking it needs to change the fuel. By doing so this puts you in the wrong timing column which can be a major problem on big injectors especially.

Once you've removed the S-AFC, check out our tuning section to lean how to be tuned the right way http://www.mellontuning.com/index.ph...dex&cPath=1_28

 

are the stock injectors big? lol cuz besides the S-AFC II and the cat. conv. removed, everything else important is stock

 

With stock injectors the AFC can remove a little fuel in the upper RPM range so it doesn't run so rich. If everything else is stock, then it's not going to do much for you. Read this;
http://www.dsmtuners.com/forums/arti...afc-works.html

 

no but the stock tune is pretty rich so you'll need to shave off quite a bit of airflow/fuel in the s-afc. Of course you need to be logging a wb02 sensor to know how much and watch the knock. (tuning knowledge required)

 

Just got this thing removed! Tuned by Micaiah in Stevens Point WI...made 284whp on a conservative 3rd gear street tune