I believe I am the first person to install an APEXi S-AFC II in a MCS. My twincharged setup required fuel enrichment so I swapped the factory injectors for the larger 440cc injectors. The S-AFC II allowed me to adjust the fuel map of the stock ecu to run with the larger injectors.
Unfortunately, I have not tried to tune a stock or pulley modified MCS yet, but my guess is that some extra power can be made on top by leaning out the mixture. The A/F is extremely rich from approximately 5500 rpm and up.
What is nice about using the S-AFC is that you can adjust the fuel enrichment yourself to complement the staged performance upgrades. But remember, nothing can substitute the use of a wide band 02 monitor when tuning, whether on the dyno, or on the road.

As soon as I find the time to test on a stock MCS, I will post the results.

 

I have considered the installation of the APEXi S-AFC II and would be very interested in learning how you tapped into the harness and how well the unit is controlling your car.

More Please!!!

 

I'm also very interested in the S-AFC for my car and being able to fuel-tune it on the street and dyno. Unfortunately, it seems that with a drive-by-wire car such as ours, it isn't as plug 'n play as it is with other cars that don't have every input go through the ECU. If you could produce a wiring diagram and let us know if there are any pitfalls to doing this, I'd greatly appreciate it.

 

>>I'm also very interested in the S-AFC for my car and being able to fuel-tune it on the street and dyno. Unfortunately, it seems that with a drive-by-wire car such as ours, it isn't as plug 'n play as it is with other cars that don't have every input go through the ECU. If you could produce a wiring diagram and let us know if there are any pitfalls to doing this, I'd greatly appreciate it.

I have had many years of experience with the APEXi electronics and was confident that it would work with the Mini ECU. It took a lot of effort on my part and some help from a great guy at Princeton Mini for me to fully understand the factory ecu harness. Once I was able to diagram the wiring, it was just a matter of integrating the S-AFC into the system. Being the first of do something always is the hardest, but also the most satisfying.

I tried both the S-AFC (now discontinued) and the S-AFC II. Both work, but the S-AFC II is a better unit and easier to configure because it has more options.
So far, I have not experinced any problems with the S-AFC II controlling the factory ECU. In fact, the car idles and drives perfect even with the larger injectors and now under WOT, the A/F ratios are perfect for my twincharged setup.

When I get a chance, I will be more than happy to produce a wiring diagram and S-AFC setup configuration.

 

My Montana Hooker and I anxiously await your How-To.

 

twinchargedmini, thanks a lot man. Really, I wasn't looking forward to throwing a chip in there and then not being able to tune it other than driving my car down to the chip-builder (in my case, hopefully it'll be GIAC) to burn me another EPROM (or whatever our ECUs use) with a custom tuned setting for my car. I have experience with Apex'i electronics as well, however not as extensive as yours. My friends own twinturbo Z cars and they use both the S-AFC and AVC-R to fuel tune and control boost. Both units are excellent and I'm glad you decided to go with the S-AFC II to fuel tune your car. Either way, I'm not in any rush, but will be anxiously awaiting your wiring diagram. Thanks again.

amir