AEM wideband to xcal3 question

[94guy]

i hooked mine up but it does not give me constant real time data? it gets the a/f as soon as it starts logging then stops. the average moves ever so little?

Originally Posted by BC_ZX3

I just finished doing this and had the same questions. Hope this helps.

Purchase a firewire cable available at most computer stores. Both ends should be identical.



Cut off one end near the connector and strip away and expose the inner wires. There will be six.



Here's the part that gives the most difficulty. Each coloured wire corresponds to a small brass pin in the other connector end. We need to determine which pin position corresponds to each wire colour. There are a couple of different colour schemes used depending on who makes the cable.



Make yourself a diagram.



Strip each wire end and then get out the handy multimeter and map each pin to its colour like so.



The result is something like that shown below. We can pick either of the two colours - in this case, red or yellow - that correspond to the firewire pins the SCT scanner uses for analog inputs. Red is Channel 2; yellow is Channel 1. We only need a single channel.



I chose red which corresponds with analog input Channel 2. Trim the other wires.



Crimp a connector on it and tape it up. You can solder it if you want; just make sure it's secure.




Now connect it to your AEM gauge harness. Use the white wire (to which I've already crimped a female connector).



Connect the rest of your wiring as shown here to power the AFR gauge. The interior fusebox is your best 12V power source and the unpainted metal fusebox housing can act as your ground. Put proper connectors on the exposed wire ends. You probably want a fusible link on the 12V power source.



Fit the unmodified Firewire cable end of your butchered Firewire cable into SCT scanner (at the top), the large SCT scanner cable end into the OBD II port of the car and a USB cable from the SCT scanner to your notebook computer, if you're using one to datalog.



When preparing to data log, go to "Data Logging" then "Set Up" in the SCT scanner menu and configure scanner analog inputs, when prompted i.e. "Configure Analog Inputs? Y/N" will appear on the screen. Select Channel 2 (or 1 depending on the wire you chose) and specify "Wideband" and then "AEM" from the scrollable list presented. This will apply a formula to the raw voltage generated by the sensor located in the exhaust stream and convert it into a more recognizable AFR ratio - the same as the in dash gauge will display - in the resulting logs.

You can datalog to the scanner itself or to the notebook using the Livelink software package.

When you've finished with the SCT data logging, simply disconnect the white analog input wire and cap it. Tie it up near the OBDII port out of sight until it's needed. Store your Firewire cable in a safe place ready for future use.

This set up worked for me without problem. Let me know if I've made any errors and I'll fix 'em.

[YellowJellyBean]

Just ordered my AEM wideband finally. I'm thinking of picking up a FireWire cable so I can datalog. Just to make sure, the wideband isn't going to help my tune unless I datalog with it, right, so the FireWire is necessary?

[1turbofocus]

Yes you will need a firewire

Tom

[Paul P]

Originally Posted by 94guy

i hooked mine up but it does not give me constant real time data? it gets the a/f as soon as it starts logging then stops. the average moves ever so little?

Looks like you are connecting the wrong wires pins 3 and 4 are analog 1. Not pins 1 and 2.

The colors might be different but the pin numbers are the key.

This would explain the issues you are having with the data logging.

[BowerR64]

Does anyone need a cable? i bought a 6' firewire to firewire and cut it in half.

Ive done all the meter work to single out the leads we need and heat shrinked off the rest.

Mine didnt have a yellow it looks more orange or pink but the same Ch2 is red as the BC_ZX3 diagrahm.

shoot me a PM if you need it i can drop it in the mail in the next couple days.

[Sean05]

Wow this is really helpfull I would've figured it out after fiddling with it forever. Makes everything alot easier for those of us that haven't done it before!

[FocusRacingAustrali]

Got my aem a/f gauge working and just want to ask if my idel number are good

13.7 to 14.5 and driving the number are still the same might go to 15 sometime????

Rob

[1turbofocus]

At idle and STEADY part throttle you should be seeing between 13.7 to 15.7 the target is 14.7

Tom

[FocusRacingAustrali]

Originally Posted by 1turbofocus

At idle and STEADY part throttle you should be seeing between 13.7 to 15.7 the target is 14.7

Tom

Been working with a guy at work who does car tuning and I ask is 14.7 good for a tune and he told me 14.7 is right on the edge of the motor letting go and you should be looking at 13's

[1turbofocus]

Then you need to change tuners because he is wrong

Tom