The guage for Narrowbands still isn't as accurate. The DB, G2, and G3 gauges are operating on a 0-5v range and tuned to run with the LC-1.
the narrow band sensor runs from about 13.5 to 15.5 and is fairly accurate. When you are more rich or more lean the gauge and sensor spike rich or lean. This is because of the sensor. The gauge is a simple .5v and works on a even curve, they seem to run that way because of what there plugged into.
I've seen the 0-1v narrowband gauges put out a different # of lights on the same car with the same O2 sensor. So you've got to figure out what voltage lights what light by programming over and over. It's better to watch the virtual gauge on a laptop and datalog it if you want. The virtual gauge is basically the XD-16 without the led's around the outside as far as response and 3 big #'s staring you in the face.
What you have is people buying some POS from JC for $25 like old Gus did that has 9 lights and is generally a POS of a gauge in the first place. Then comes how accurate a gauge can read by how much voltage each light runs on. A daws with 4 lights has a lot larger range than a 9 light, same goes for my Autometer gauge with 18 lights. The Autometer is a quality gauge with enough lights to show the range better.
Then comes the real issue with gauges, there real actual job, a warning light. Your not going to use the gauge for fine tuning unless you spend $400 and buy the XD-16. Unless your running D cal, which very very few are or any custom computer, you do not need to be able to read the numbers. The vast majority of us will simply adjust the AF with the fuel pressure regulator and or send the cal in for an adjustment. You hook up the laptop and find the AF you want, then thats it. The gauge needs to tell you if you lose a vac line or something and there is a problem. Are you really looking at your floor boards staring at your G3 to see the exact number while racing? I dout it. The old type gauges are much better for doing the job after adjustment because they warn you with a color light. I don't have to look for the number, the color changes and I lift. What do you do with a G3? "well I wasn't watching but I think it said 12 before it melted, or was that 14 I saw" :drinking: So at that point the best is either a laptop and a old gauge or a XD-16 as the XD has a color bar like an Autometer. But still even with a flashable D cal wouldn't you want to make a run with the LC-1 data logger hooked to the laptop and compare the AF curve to your computers fuel curve when finished?
So for tuning the commen TD you need a LC-1, a cheap $100 laptop, and an old OTC. Adjust your fuel pressure lean untill you start pulling timing and back it off, or play it safe and run a hair rich without pulling timing. Then you got a color warning light and a boost gauge making sure the turbo and the vac lines are doing there jobs. Then adjust the LC-1 output to get a little mileage. I think the D cal people should consider a EGT gauge for messing with the timing.
