A Few ProEFI Questions

Hello everyone,

I hope I posted this in the right section. I’ve ordered and received the ProEFI 128 system for my ’98 Mustang Cobra. I have done quite a bit of research and I am in the middle of wiring it up now. So I have made it this far but I have a few unknowns that I’ve run into that hopefully people on here can help with. Just for background purposes, here is the basic set-up:

• ’98 Ford Mustang Cobra 5.3L (4.6 punched out) 4V, 10:1

• 1680cc high impedance injectors

• Twin 6266 turbos

• Built 4R70W trans, triple disk lock-up converter

• ProEFI 128 with flex fuel, iboost, ProEFI fuel pressure sensor, ProEFI MAP sensor, ProEFI boost control solenoid, dual ProEFI widebands, OEM Ford TPS, IAT, IAC, ECT, Crank/cam sensor, and knock sensor. All the Ford sensors will be shared with the stock ECU using a jumper/adapter harness I made.

• LS2 ignition coils

• Ethanol based fuel of varying percentages

I’m at the point where I need to input the necessary speed sensors. The car has ABS so I have access to both front and rear ABS wheel speed sensors if needed. It apparently will fault the ABS computer if I share the sensor wires but that’s ok. The car isn’t driven in the rain/snow anyway. Now here is where my questions comes in. My car was equipped with a VSS sensor mounted in the tailshaft section of the 5 speed manual trans. The signal from this sensor is mainly used to run the speedo. It does get inputted into the OEM ECU but it’s not really used for anything important—especially since I’ve swapped to an auto. The speedo is not run by the OEM ECU. But when the guy built my trans, he mistakenly installed an OSS sensor into the auto rather than the VSS that I specified. Both of these sensors have a reluctor wheel and a magnetic sensor inside, but the signal timing is very different between the two generations. So now my speedo was way off (read high I believe). So there’s a device called a SpeedCal that I installed that allows you to calibrate it. It’s also handy when you swap gears or swap to a larger tire because you can easily calibrate the speedo accordingly. So the SpeedCal puts makes it look like a normal VSS signal again vs. an OSS. A friend of mine also said the only difference now is that the new signal is a square wave vs. a sine wave. I am not an Electrical Engineer or electronics guru so whatever he says, lol.

The dealer I bought the ProEFI from flashed in a base MAP. They never asked what type of speed sensor I had in the car. They have done a couple of later model Cobras with an OSS sensor so I suspect they may have modeled the base MAP for my car off of the later model OSS equipped Cobras that they have tuned. So now this leads me to some questions regarding the speed sensors and the ProEFI.

1. Will the square wave vs. sine wave signal make any difference to the ProEFI? It makes no differnce to the OEM ECU but I just wanted to make sure with the ProEFI.

2. I’ve read that there are three ways to set up the traction control—1. Front/rear wheel slip differential 2. Driveshaft/vehicle speed dependent 3. Rate of engine acceleration in each gear. My car is mainly a street car with limited track duty. I’ve read that for a high HP, traction limited auto car, the 2nd option might be best. But I’m not sure. Which one appears to be the best option or does it matter?

3. There are three speed sensor inputs listed on the ProEFI pinout. J1A01-Driven wheel speed sensor input, J1A12-Non-driven wheel speed sensor input, J1C14-Vehicle speed sensor #2 input. Then you have J1A32 for the returns. It’s pretty obvious that J1A12 would be for a front wheel speed sensor. Can I or should I input both the VSS signal (as described above) and the rear ABS signal into the two speed sensor input pins? Which goes to which or does it matter? I’m assuming it depends on which traction control method I use whether I use both of these? I guess I’m trying to understand what exactly each speed sensor can be used for, which ones would be best for what, and which ones I should input. Apparently these sensors are used by the ProEFI for other things also besides the traction control so I want to make sure everything is right and that I have the most flexibility. As I mentioned, it will be lot easier to wire them in now since I’m in that phase of the project. I don’t want to go back and add wires later.

4. I have not looked at the base MAP yet so I am not sure how it was set-up in regard to the speed sensor(s). Once I determine the best/optimum way to go, I will get into the tune and set/reconfigure it accordingly. I'm assuming the ProEFI can accept either an OSS or VSS signal and can be mapped accordingly to the actual vehicle speed?

I hope all of this makes sense. I just want to make sure the ProEFI can read the signal I described and what is the best way to set all this up for the most flexibility and function. I guess with no instructions whatsoever, it’s hard to tell how the ProEFI was designed to utilize these various inputs.

Thanks for any help!

Turbo98 wrote:

Hello everyone,

I hope I posted this in the right section. I’ve ordered and received the ProEFI 128 system for my ’98 Mustang Cobra. I have done quite a bit of research and I am in the middle of wiring it up now. So I have made it this far but I have a few unknowns that I’ve run into that hopefully people on here can help with. Just for background purposes, here is the basic set-up:

• ’98 Ford Mustang Cobra 5.3L (4.6 punched out) 4V, 10:1

• 1680cc high impedance injectors

• Twin 6266 turbos

• Built 4R70W trans, triple disk lock-up converter

• ProEFI 128 with flex fuel, iboost, ProEFI fuel pressure sensor, ProEFI MAP sensor, ProEFI boost control solenoid, dual ProEFI widebands, OEM Ford TPS, IAT, IAC, ECT, Crank/cam sensor, and knock sensor. All the Ford sensors will be shared with the stock ECU using a jumper/adapter harness I made.

• LS2 ignition coils

• Ethanol based fuel of varying percentages

I’m at the point where I need to input the necessary speed sensors. The car has ABS so I have access to both front and rear ABS wheel speed sensors if needed. It apparently will fault the ABS computer if I share the sensor wires but that’s ok. The car isn’t driven in the rain/snow anyway. Now here is where my questions comes in. My car was equipped with a VSS sensor mounted in the tailshaft section of the 5 speed manual trans. The signal from this sensor is mainly used to run the speedo. It does get inputted into the OEM ECU but it’s not really used for anything important—especially since I’ve swapped to an auto. The speedo is not run by the OEM ECU. But when the guy built my trans, he mistakenly installed an OSS sensor into the auto rather than the VSS that I specified. Both of these sensors have a reluctor wheel and a magnetic sensor inside, but the signal timing is very different between the two generations. So now my speedo was way off (read high I believe). So there’s a device called a SpeedCal that I installed that allows you to calibrate it. It’s also handy when you swap gears or swap to a larger tire because you can easily calibrate the speedo accordingly. So the SpeedCal puts makes it look like a normal VSS signal again vs. an OSS. A friend of mine also said the only difference now is that the new signal is a square wave vs. a sine wave. I am not an Electrical Engineer or electronics guru so whatever he says, lol.

The dealer I bought the ProEFI from flashed in a base MAP. They never asked what type of speed sensor I had in the car. They have done a couple of later model Cobras with an OSS sensor so I suspect they may have modeled the base MAP for my car off of the later model OSS equipped Cobras that they have tuned. So now this leads me to some questions regarding the speed sensors and the ProEFI.

1. Will the square wave vs. sine wave signal make any difference to the ProEFI? It makes no differnce to the OEM ECU but I just wanted to make sure with the ProEFI.

2. I’ve read that there are three ways to set up the traction control—1. Front/rear wheel slip differential 2. Driveshaft/vehicle speed dependent 3. Rate of engine acceleration in each gear. My car is mainly a street car with limited track duty. I’ve read that for a high HP, traction limited auto car, the 2nd option might be best. But I’m not sure. Which one appears to be the best option or does it matter?

3. There are three speed sensor inputs listed on the ProEFI pinout. J1A01-Driven wheel speed sensor input, J1A12-Non-driven wheel speed sensor input, J1C14-Vehicle speed sensor #2 input. Then you have J1A32 for the returns. It’s pretty obvious that J1A12 would be for a front wheel speed sensor. Can I or should I input both the VSS signal (as described above) and the rear ABS signal into the two speed sensor input pins? Which goes to which or does it matter? I’m assuming it depends on which traction control method I use whether I use both of these? I guess I’m trying to understand what exactly each speed sensor can be used for, which ones would be best for what, and which ones I should input. Apparently these sensors are used by the ProEFI for other things also besides the traction control so I want to make sure everything is right and that I have the most flexibility. As I mentioned, it will be lot easier to wire them in now since I’m in that phase of the project. I don’t want to go back and add wires later.

4. I have not looked at the base MAP yet so I am not sure how it was set-up in regard to the speed sensor(s). Once I determine the best/optimum way to go, I will get into the tune and set/reconfigure it accordingly. I'm assuming the ProEFI can accept either an OSS or VSS signal and can be mapped accordingly to the actual vehicle speed?

I hope all of this makes sense. I just want to make sure the ProEFI can read the signal I described and what is the best way to set all this up for the most flexibility and function. I guess with no instructions whatsoever, it’s hard to tell how the ProEFI was designed to utilize these various inputs.

Thanks for any help!

It's best to send these questions to Tech@proefi.com