legacycentral bbs

SunPro are the wonderful cheap gauges at your local PepBoys/ Autozone as many of you know. wonderful solutions for the cheap enthusiast. recently they added electronic A/F gauges to their lineup. The resolution is only 3 LED bars per section (3 bars in lean, 3 in rich, 3 in stoich). is that enough resolution to be worthwhile? I mean, the gauge is only 24 bucks! should I shell out the 25-50 bucks more for something with a higher resolution?

As I remember, most of them just have 10 LEDs, since they're just driven with LM3914 chips which have 10 outputs. Some of the nicer ones chain two 3914s together and have 20 LEDs, but most have 10.

I would rather have fewer lights on the indicator, all that is really needed is six two in the lean range two in the center and two in the rich more than that and it's all lights. The LM3914 can be wired this way.What I did was put a meter on the line and noted what light came on at about .85-.9 volts that is about 12.5 to one AF mixture for max power.
AL(CO)

I ended up getting this one: EFI Systems Air Fuel Ratio/Injector Duty Cycle Meter:
From the makers of the PMS, this meter is a small black box containing two sets of 10 LEDs (red, yellow and green) which display your engine's air/fuel ratio (over the range 12.3 to 16) and injector duty cycle (0 to 100%). Unlike the other gauges, this one mounts using double-sided tape (not included) to your dash. This unit isn't as easy to read as the Extreme A/F, as only a single LED lights on each of the two bar graphs, but it's the only gauge available that can also read out injector duty cycle. Wiring is the same as the other gauges, except this unit also taps into one of your injector lines.

It's not the best looking gauge, but it does tell injector duty cycles. But, as Adam explained, it's not as accurate but gives me a ballpark figure. I've been able to wire in injector duty cycles, but can't find the O2 sensor wire . . . yet.

It can be found here: http://www.extrememotorsports.com/gwcat/full.htm

Jason