Thread: EFI Tuning

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I've been struggling to get my SBF 347 EFI tuned, and had made some adjustments to the injection map using the Handheld Calibrator LED's fed by the base narrow band O2 Sensor - it has Red (Lean), Amber (14.7:1) and Green (Rich) LED's, and theoretically should work for a street tune but I was getting exhaust pops and other problems that had me a bit baffled. Last week I ordered a Wide Band O2 controller and gauge, and this weekend made a little box to hold the indicator, LED and calibration PB along with an adapter pipe for the O2 sensor. Sunday afternoon was test day, and I was amazed at how badly I had messed up the fuel map. I think my narrow band sensor response is a little slower, but mostly it is simply that the range measured is only 14 to 15 AFR while the wide band range is 7.35 to 22.39 AFR - the narrow band resolution is so tight, and the response is so fast that it is actually just a switch. With a red LED you know you're above 15AFR but no idea how lean, and with green you only know you're below 14AFR. Being able to watch the AFR change throughout the power band is such a powerful tuning tool it actually makes it a fun exercise to make an easy pull, note areas where the mixture is off, and to have an idea of how much adjustment is needed in the map to bring it back to the sweet spot. This is the Innovation controller unit I picked up for $170, and my home-made setup to make it functional for tuning. The exhaust extension simply slips over the baffle tube and clamps with a hose clamp. Works slick!!