How to: SplitSecond AFC (SSAFC) Install, R4 Software Overview


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Hello all! While the APC-SplitSecond PSC1 Map Library thread exists and is great and full of information, I find that it's kind of a pain to read through 2500+ posts to pick out information especially for those just getting started. The forum is full of threads with information on the SSAFC and R4 software so do some searching if this article doesn’t answer your questions.

The purpose of this thread is basically a crash course for:
  1. Installing the SSAFC unit
  2. Using a proper USB to Serial cable
  3. The basics of the R4 software
This how-to is dedicated to @Dpwhitehead1 and @Gabe710 :geek:

I'm no professional but I'm just trying to help out people new to this SSAFC stuff

Disclaimer: I'm not responsible for any damages that may occur to your car during installation of the SSAFC.

Caution: Please be safe and do not endanger yourself or others on public roads. It's not worth it. Sorry, I do drive like a grandma believe it or not :)

Installing the SSAFC unit
  • There are two versions of the SSAFC, the v1 (without data logging) and the v2 (with data logging). If you bought your unit used and cannot tell the difference, the version with data logging has 4 orange wires.
  • The installation instructions are provided in an image below. The ECU is located in the passenger side floorboard.
  • Use your best judgement for splicing and connecting wires.
  • If you purchased your unit brand new the SuperMapStock map should be loaded onto it. Else you'll need to download the that's attached in this post. Writing a map to the ECU will be covered later.
  • ssafc-install.jpg
USB to Serial Cable
To avoid connection issues from your laptop to the SSAFC unit, do not run a cheap USB to Serial cable. Speaking from experience, it will 100% fail on you while attempting to save/load a map and data-logging. 🤦‍♂️


This is the cable I use is tried and true and it even comes with it's own drivers:

Gearmo USB to Serial Adapter RS232 with LED Indicators Windows 10, 8, 7, Vista, XP, 2000 (commissions earned)


I don't remember the order of operations for the cable but I don't think it matters.
  • Plug in the cable to your laptop. It will complain saying it found new hardware. Most likely it will not successfully install itself.
  • Install the drivers by selecting the proper operating system drivers in its respective folder
  • Once the installation has completed, it’s time to find which COM port is assigned to your USB to serial cable. Open the Device Manager, expand “Ports (COM & LPT)”, locate the USB Serial Port (COM#). In my case, it is COM4. You’ll need this information for connecting to your SSAFC using your laptop later. 💡


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The Basics of the R4 Software

Install the software.
Use the installation wizard. Pretty standard and no explanation needed.

Open a Customer file and Verify Settings
The R4 software calls the files it handles customer files. The customer file contains settings for the SSAFC, fuel map, and data-logs.
  • Open the R4 software
  • Load a customer file.
  • Verify the settings in the customer file:
  • Go to Options -> System Settings and verify the options Vacuum/Pressure and Programmable Signal Calibrator are selected
  • Go to Options -> Engine Settings and verify the options 4 Cylinders and 4 Stroke are selected.
  • Go to Options -> Output Settings and verify values match values from screenshot. I'm not sure what all these settings do, but Over Pressure tells the AFC when to take over. Default is 1.1psi but some people have better luck with 0 or -1.
  • Go to Options -> Aux Input Settings (Units with datalogging). Here you have 4 Aux Inputs and each input correspond to an orange wire from your SSAFC. If you run an AEM wideband, I can tell you that coefficient a is 10 and coefficient b is 2. Without getting into detail, it's the values used to calculate the AFR so you can read it on your data-logs. Otherwise it's read and logged in a different unit. Lambda perhaps? If you use another brand wideband, you can refer to your instruction manual or contact the vendor for further help. Here's a tip: If you don't know which Aux Input is your wideband yet, just fill in the coefficient values for all aux ports. No harm done.

Connecting to the SSAFC
  • Have laptop present, R4 software opened, and desired customer file opened.
  • Plug in the USB to serial cable into your SSAFC and laptop.
  • Using the COM Port you found in the device manager from earlier steps, select the COM Port from the drop down select 💡
  • Turn the key to the ON position without starting your car.
  • Click on the Connect to ECU button
Disconnecting from the SSAFC
When connected, simply click on the Disconnect from ECU button if you're connected.

It's good practice to disconnect before unhooking the USB cable or turning off your car if you were data logging to avoid corrupting your customer map file data.

Fuel Maps
  • In the fuel map window, there will be an option for Map A and Map B. Map A is the only map you're concerned with here since it's your fuel map. Map B isn't used on the SSAFC. If you're curious, Map B is the timing map used on the SSFTC which allows you to retard timing but is not capable of advancing timing.
  • In the fuel map window, you're able to
    • Read data from ECU
    • Write data to ECU
    • Adjust fuel the map.
Read data from ECU
  • Read data from ECU will take the current map on the SSAFC and save it onto the current customer file you have opened on your laptop. In a nutshell, saving the map from the SSAFC to your laptop. I usually create a new customer file off of the SuperMapStock.mdb if I forget what map is currently loaded on the car and I need to save it to compare to other map files I have.
  • To read data from ECU, follow the instructions from Connecting to the SSAFC.
  • After successfully connecting to the SSAFC, open the fuel map window.
  • The first button on the toolbar is for saving the current map from the SSAFC onto your laptop.
  • When ready, click on the Read data from ECU button and allow saving to complete.
Write data to ECU
  • Write data to ECU will take the map from the customer file you have opened on your laptop and write it onto the SSAFC. In other words, load a map from your laptop to the SSAFC.
  • To write data to the ECU, follow the instructions from Connecting to the SSAFC.
  • After successfully connecting to the SSAFC, open the fuel map window.
  • The second button on the toolbar is for writing the map from your laptop onto the SSAFC unit.
  • When ready, click on the Write data to ECU button and allow writing to complete.

Adjusting fuel map
  • With the fuel map window opened, you'll see a chart that displays RPM x Hg/Psi (based on the System Settings)
  • The cell value 10 means let the MSP ecu do the thinking.
  • Locate the RPM and boost psi where you feel the need to increase or decrease fuel, based on datalog or visual validation of course.
  • Decreasing the cell value means decreasing fuel, thus a cell value of 9.0 will spray less fuel than a cell value of 9.5 💦
Words of wisdom
Be warned, while there is an undo button, there isn't a way to revert your changes to the fuel map after closing the fuel map window or if you lose track of your changes and forget where you left off. Ask me how I know. It's a pretty good idea to make a copy of a customer file before making changes. This way you’ll have a backup in case your car doesn't like or agree with the new fuel map you just uploaded. Again, there is no easy way of undoing or rolling back.

Example workflow:
  • SuperMapStock.mdb - this is the original map so I'll keep it untouched. I'll make a copy of it and play with that instead and call it SuperMapStock-323-1.mdb.
  • SuperMapStock-323-1.mdb - I made changes to the fuel map, wrote it to the SSAFC, car is happy 🤩
  • I want to make more changes. I make a copy of SuperMapStock-323-1.mdb and name it SuperMapStock-323-2.mdb.
  • SuperMapStock-323-2.mdb - I made changes and oh no, my car is running too rich or lean and it's hitting fuel cut 💥 but I forgot what I changed before. Good thing I still have my previous map!
  • SuperMapStock-323-1.mdb - Put this map back onto the SSAFC and car is happy again.
  • I’m done. I’m never touching this tuning stuff again! 😂
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  • To data-log, follow the directions from Connecting to the SSAFC except this time actually start the car.
  • Once the car is started and the SSAFC is connected, click on the Start Capture button.
  • Go driving as you normally would and it will record data for RPM/boost/wideband and whatever else your creative self can hook up on the aux wires.
  • Personal preference, always hit the Stop Capture button before disconnecting hardware or turning the car off.
View Data-logging
  • Open the customer map file you data-logged on
  • Go to View -> View Recordings
  • Select the Recording to view from the drop down menu
  • In this view, I've turned off the lines that aren't used. The lines on are RPM (red), Pressure (green), and Wideband (brown)
  • Click on a point in the map and the fields on the right will tell you what it recorded
    • RPM: self explanatory
    • Pressure: boost pressure in psi
    • Table A: refers to Map A and is the cell value from your fuel map
    • Table A V: The MAF voltage for the corresponding cell value from your fuel map
    • Table B: Not used on the SSAFC
    • Table B V: Not used on the SSAFC
    • Aux Input: One of these is your wideband displaying the AFR if you set the coefficients correctly in the settings.
    • Total Time: time left until you join the zoom zoom boom club. Just kidding

Additional info worth noting
The SSAFC unit can only control fuel up to 16psi as you may have noticed in the fuel map. Values in the 16psi fuel map column will then be used for all boost pressures the unit sees upward of 16psi. The SSFTC unit can control fuel up to 26psi I believe.

That's all folks.
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No personal experience with it but I found a t3/t4 map:
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Enjoy! I've been meaning to type this all up for a while now. I will happily correct mistakes and add in additional information if necessary.
If I damage my car, dont be surprised by the knock on your door... JK but thanks! Hopefully in a few weeks (;
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This is a thing of beauty! Thanks for sharing this with the Community, @323 (y)

Note that we have a new feature called Resources where you can post How-Tos etc like this fine example and I've created one (as a link version) to promote this thread...
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