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Case Studies : Apexi Super AFC Wiring Diagram : How to install a AFC.

While the age of the piggyback computer is slowly coming to an end, many enthusiasts would be remiss to overlook the benefits of adding a piggyback such as the Super AFC to their vehicle for tuning flexibility.

So people have been asking for diagrams and sending questions regarding the APEXi SAFC unit. I have included a scanned image displaying the wiring diagram and how to install steps below :

And here are a few links to previous Case Studies where we install the AFC and tune it.

Installing SAFC into a MKIV Supra

Installing SAFC into a Dodge SRT-4

Tuning SAFC – How to tune your car for dummies

Happy tuning!

 

Project SRT-4 : Back on the road and tuning with the AFC

Project SRT-4 has been on a long hiatus, and after popping the headgasket late in 2008, we’ve finally gotten back around to getting this monster back on the street. Since it’s been a few weeks since our last update, let’s run through a quick recap.

Staying with the stock bottom end, we’ve chosen to run a Cometic head gasket for the SRT-4 along with ARP head studs to keep the 2 halves together.

Head is assembled, cams and cam caps torqued and assembly lube generously applied. Next, we torque down the head, following the SRT-4 tightening sequence.

Now onto the real challenge, installing and fabricating the downpipe, chargepipe and turbo kit on the back of this motor. What you are looking at is a 50mm Tial wastegate, DNP Turbo manifold and the back of the motor.

Project SRT cracked 350 whp on my Dynojet448x using a slightly upgraded stock turbo and stock fuel. Since then, we’ve stepped up to a 62-1 Garrett T3/T4 turbocharger in hopes of chasing down 440 whp on 91 octane.

Unfortunately, that also means ditching the stock manifold, turbo and downpipe, and if you’ve ever seen the SRT-4 Engine bay, you know how much of a bitch this is going to be.

After quite a bit of cursing and yelling, we’ve mounted and installed the turbo, manifold and wastegate, but our problem is still the dumptube.

Here’s a shot of under the car, looking at the back of the motor between the firewall and subframe. If you see the 2 power steering lines going into the rack there, that is about the only space we have to route a dumptube.

Time to get lucky.

Using a Vibrant V-band flange, we weld a 1.75 inch J pipe and completely hack up the bend to get the radius as tight as humanly possible.

After a lot of cutting and hacking, we’ve got a pipe that allows us to bolt it to the wastegate egress, but the bend is not tight enough to clear the power steering lines or alternator properly. Further, the opening is not large enough for us to cut and reweld, and instead of removing parts again, we’ve opted to heat up the pipe and bend as need be.

Unfortunately, we forget that the dump tube is 304 stainless.

It look a whole lot of heating and bending, but we finally got the screamer pipe to bolt on and clear all the lines properly.

A look at the finished product, note the clearance on the power steering lines as well as the clearance to the charge pipe coming off the turbo.

Now with that out of the way, we go to tune the SRT-4, only to find that the AFC NEO has a blank screen and refuses to turn on. This is a fairly common issue for these piggybacks as people love to yank and pull on the wiring loom, pulling the daughter board out of the AFC PCM.

To fix this issue, simply remove the hex bolts on the back of the AFC NEO and gently pull apart.

After plugging the harnesses back into the daughterboard, we snap the NEO back together and reinstall the hex bolts.

Your NEO may or may not go into DEMO mode, a mode in which the screen flashes and is not responsive to any button inputs. To solve this issue, turn the car off and then turn it back on while holding the UP button on your NEO.

This will force it into a diagnostic mode, where you must select to “reset” the NEO to gain control of it again.

After all the little BS issues are taken care of, we dial in the boost at a very low 10 psi and hit the streets with a datalogger to get some rough tuning out of the way.

Next up?

Dyno time for the SRT-4 as we chase 400hp on 91 octane.

Happy boosting!

Piggyback Heaven – Installing a SAFC NEO in a SRT-4

Today we are installing the ever popular SAFC NEO into our Project SRT-4. While piggyback computers aren’t as commonplace today as they were 10 years ago, they are still quite useful for the tuner on a budget.

While I install quite a few AFC NEO’s, I don’t recommend this install for the SRT-4 due to the difference in TPS and MAP sensor voltage. The AFC NEO operates in a range from 0-5 volts, where as the SRT-4 does not.

When you add aftermarket injectors such as the 760cc ( or 76# for those domestic fellows ), you can cause all kinds of problems without a device to lean out the mixture. Using a SAFC, we aren’t truly “leaning out” or “turning down” the fuel, but rather fooling the ECU into seeing less air, thus accomplishing the same result.

OBDII vehicles such as our SRT-4 have 2 values you should keep your eyes on, the STFT ( short term fuel trim ) and LTFT ( long term fuel trim ). When the SRT-4’s ecu sees the overly rich condition created by the larger injectors and upgraded fuel system, it will decrease these values in a vain attempt to restore “normalcy”

The problem is, when the SRT-4’s STFT and LTFT reach a value of -14, the ECU throws the ever popular P0170 Check Engine Light, Fuel Trim Malfunction (Bank 1).

By installing our SAFC NEO, we can lower the airflow value before it reaches the ECU allowing us to adjust the injector pulse width and therefore leaning the vehicle out.

Tools you will need for this install :

  • Soldering iron
  • Solder
  • SAFC NEO
  • 10mm wrench
  • wire cutters

First you must undo the ECM, held to the chassis by 10mm bolts, then unplug the ECM terminals.

FIrst, locate your C1 connector, the fourth plug down on your ECM, it will have an BLACK housing.

Here is a look at front face of a ECM connector, the back of this connector is what you will need to pull off.

You will have to pull back on the mounting tabs ( all four ) and pull the back half of the housing off to expose the wires.

I really really really hate these connectors......

With the back half removed, we’ll start the wiring fun by starting with our ground wires. The two wires in question are brown and black, locate those on your AFC harness and find pin 18 on your C1 module.

Using your wire strippers, expose 2 spots of the wire approximately 2 inches apart. The brown wire needs to be soldered in before the black wire, and closer to the ECM.

With your grounds properly wired in and installed, we now move to the 2 power wires on the SAFC NEO. Locate pin 11 on ECM Connector C1, this pin is a blue wire with a red stripe.

Wire in your red wire and red with white stripe on the NEO harness to pin 11, in the same method as you did the ground wire. Make sure the red wire with white stripe is closest to the ECM.

Now with the power and ground sorted out, move onto the MAP signal wires on the NEO harness. These wires are white and yellow on the NEO harness, we will also be wiring the TPS wire ( gray NEO wire ) in at the same time.

Now locate pin 23 on orange ECM connector C2, pin 23 is a dark green / red wire. This wire should be cut, and the yellow NEO wire must be wired in leading TO the ECM.

The white wire is then wired into the opposite side, make sure to solder for best connection.

Now with the white wire connected to the vehicle’s MAP sensor, take your gray throttle position sensor wire ( gray ) and wire that inline with the white NEO wire. Make sure to wire the gray TPS signal closer inline to the actual MAP sensor found on the intake manifold.

Why wire the gray wire into the MAP sensor? because of the SRT-4’s 3-7 voltage range, the NEO’s normal operating range of 0-5 will cause issues when tuning fuel trims according to throttle position. Using the MAP sensor, we can tune for engine load, as opposed to guessing and hacking our way through different voltage ranges.

Here is an example of this wiring, please note the brown wire depicted is the actual gray TPS wire, and the light green / red wire is the NEO white wire. Sorry I had to extend the wires using another loom and didnt have colors available that were close to gray or white for that matter.

Now find your green RPM wire on the NEO harness, this should be wired into a tach adapter, msd part number 8913.

Connect to the gray Tach adapter wire for a consistent rpm reading based on the vehicle’s spark.

Now with your NEO fully wired up, make sure to pick up some loom and clean up your rat’s nest!!!

Now to setup your AFC NEO, go into the menu and select sensor type as “Pressure” as your SRT-4 operates on a MAP sensor.

Select the “in” value as 10, set the “out” value as 10 as well.

Go into the car setup, and change the cylinder value to 4 and set the “thr” setting to the arrow pointing up and right.

Now go into the “TH-POINT” Menu and set your throttle values to 20% for low settings and 80% for high throttle.

For example if your MAP sensor sees load under 20 percent, then it will use the low-settings on the AFC for adjustment. Anything higher than 80% will run off the high throttle map and anyhing inbetween the two maps the neo will interpolate between the 2.

Now run the NEO Harness inside the cabin, and you are all set!

Happy Boosting!