MalibuJack from another thread..

.. basically there are lo-throttle, hi-throttle, NE-Points, etc.. Its all documented but the docs aren't easy to follow.. MOST of the s-afc settings only address the high throttle points, and most have adjustments at 3000rpm and higher.. and for many of us, the high-throttle point is at 60%, though I've seen several with points higher than that.. and one or two with theirs set lower..

Basically that 60% value means that your throttle position switch needs to read at 60% open before the S-AFC adjusts the max value of the MAF signal (Edit: The adjustment happens between the low-throttle and hi-throttle points, but the value is at its max at the high point - thanks Mark), keep in mind that with the evo, the 100% open TPS isn't really where your foot is planted to the floor, its somewhere around 2/3's to the floor.. thats why these values are important to set and pay attention to. it more or less reflects the point at which the car switches from closed loop operation to open loop maps.

Any high-rpm setting (7000rpm or so) with 93 octane with more than -19% compensation is going to run extremely lean.. I wouldnt go more than 16% with 91 octane.. how you taper from 0% through that point is going to depend on your driving style and how your cars modifications respond..

(EDIT: as mentioned in another post, I think it was determined that the point the engine goes from CLOSED loop operation, to open loop is approx 30% TPS reading.. This may or may not be accurate, I can verify this on a data logger at some point in the future)

On a car with stock boost, you can actually lean it out a bit more than 19% if your running 94 octane, But I wouldn't attempt it until you can see what your actual mixture (With a wideband a/f) and egt's are..

Oh, and just so you know.. just installing and initializing the S-AFC will result in a stock setting, its only when you adjust the lo-throttle or high-throttle compensation that it alters the MAF signal.. a positive value makes it richer, and a negative value makes it leaner.

I wish I could give you step by step instructions, but I don't have the new S-AFCII to document it.. HOWEVER, the first two items to set are

Low-Throttle at about 30-35%
High-Throttle at (for most) 60%

NE-Points can be set for 500 rpm increments through 7500rpm
(2000,2500,3000,3500,4000,4500,5000,5500,6000,6500 ,7000,7500) I think that's 12 points..

(Edit: NE-Points on the S-AFCII are at 200rpm increments, not 500)

You can now take the values that you've seen here and map them as closely to an NE point in that list.. the points in between you can average the difference if needed.. any below the area you start compensating, around 3000 rpm, you can just leave at 0.. but don't leave any points between at 0...

I hope this helps you translate the settings.


If you plan on modifying the settings yourself after you have a baseline, I cannot begin to emphasize how important using a A/F Gauge (Wideband is better) and EGT probe.. You also need to have some form of performance benchmark to determine if what your doing is improving things, otherwise tuning it yourself is pointless.. We do this at the track pretty frequently..

 

That was a very very good post RE: S-AFC II.

I only changed LO throttle settings at 1000 and 1800 RPM tad bit leaner.

High throttle settings - from 4800 rpm, -9% and gradually gets leaner to -17% at 7200rpm.

This setting came with the unit at the shop I bought...

i don't have an access to the track or dyno so I wasn't going to change any of the settings. But after reading this post, it made me want to tweak a little bit.

oh, Hi throttle % is 60 and lo is 35 by the way.

Thank you for the very detailed post.

 

Where can I get some more information about seting up S-AFC for my Lancer OZ???
Do you know any dealers/shops/distributors???
thx

 

I think 17 at red is too lean... be carefull.. I only have a max of 13 on mine... I havent dynoed (wide band readings..) it yet so I am playing it safe.. got my settings from cal at gruppe-s.

 

Its nice to see some of the information I posted in the past is helping you guys out.. I'm not sure where, but there's a detailed thread in another forum (engine and drivetrain probably) that should be moved here.. it has quite a bit of useful S-afc info..

 

Actually your post helped me big time... I had to print it out and re-read it several times and had the paper with me when I was hooking up my afc.. many thanks kind sir..

 

that sounds like the br settings. i used them and they were too lean for me. i got a wideband and did a little late night tuning. i then hit the dyno and cranked out about 20 more horses than before with br settings, plus a lot safer. might wanna invest in a wideband, it was the best investment for me so far. jason

 

They can be a bit lean if your boost is over 19psi...

 

care to elaborate jack? I got 91 oct and my lowest is -13 on red.. care to post any settings? and what PSi.

 

I found when I was analyzing the settings that anything over -15 was just too lean on my car with 21psi of boost.. -13 is fairly safe for 19-20psi of boost as long as your not getting knock..

Since I no longer have an S-AFC I can't give you any accurate settings, but I can infer settings from my UTEC, and somewhere around -7 to -9 seemed to have the best AFR at high RPM with 21psi of boost.

The biggest issue most of you guys will experience is a lean spot in the midrange due to aftermarket intakes, MAF pipes, and open element filters.. That I just can't give you any suggestions for except that you'll need to go a little rich +2 to +3 from 3000-4500/5000 but again, without a wideband on your car, it'll be hard to tell.. this would be something you would need trial and error since many people aren't dyno or road tuning S-AFC settings with a wideband O2 sensor any longer.

 

Thanks man.. as usual.. your very helpfull..

 

wait... why arne't people tuning with wideband o2 anymore?

 

People with the S-AFC aren't generally tuning with a wideband because many who are serious about it end up getting different engine management solutions, or have had their cars professionally tuned.

 

Malibu, I was wondering if u can elaborate more on "NE points" im not to sure how to set that,also correction%, and if getting some knock while accelerating thru hi throttle is bad? I got the SAFC II Version 2, and im pretty new to it(actually new to tuning fuel) Help me out man!!!...