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SD Cable : Decision Criteria
ECMTuning offers a “plug and play” SD cable for sale on our website.
This cable provides connectors for our Omni 4-bar (or GM 3-bar) MAP sensor and GM/AEM IAT sensor on one end and then a connector that plugs directly into your car's MAF connector on the other. It's meant so that you can completely replace the factory MAF sensor with the SD sensors.
That's good and bad. The good is obvious. It's a clean, simple install procedure.
But if you already have the car running well on the MAF sensor, it's nice to be able to auto-dial in the VE table using our SD VE Adjust procedure. Read through that page for more details, but the basic idea is to let the laptop application calculate your VE table for you as you drive around on a well calibrated MAF setup. Then, when you remove the MAF and switch to SD, you have a really good starting point for your engine already setup and ready to go.
The problem is that you have to be able to run on the MAF sensor while simultaneously datalogging the MAP signal in order to use this tool. And if you plan to run our SD cable, you can't exactly do that because the SD cable replaces the MAF sensor.
So there are a couple options to consider. Neither of which is perfect.
Option 1
This option is the more obvious of the two…you simply don't use the auto dial in procedure and just swap directly from MAF to SD.
You can still use the other automated SD VE Adjust procedure to dial in idle and cruise based on combined fuel trim data while running on SD. It's just not as automatic and doesn't cover as many operating conditions as the MAF-based procedure. But it certainly works fine.
Option 2
You can order the SD cable and then manually run the MAP sensor into a different input while you run on the MAF sensor and dial in the SD VE table. When you're done, you can undo the MAP sensor install you did before and then plug it up into the SD cable.
This option isn't great because you're basically doubling your install effort and you're going through the process of wiring in the MAP sensor manually anyway. That was one of the main benefits of the SD cable…you didn't have to manually splice in a pig tail.
But…it's an option to consider if you're end goal is to have the clean SD cable install *and* you'd like to use the auto dial in procedure off your MAF.
