i was looking at an auto meter unit but it runs off the O2 sensor voltage up to 1 volt, and a while back the Ogre said that we have a narrow band and its not a good indication of A/F ratio.
Sombody please explain, thanks
IP: Logged
01:07 PM
PFF
System Bot
FieroJoe Member
Posts: 2314 From: Southfield, MI Registered: Nov 2000
If you're talking about the Autometer digital A/F ratio gauge with all the LED's, I think mine's great! I think that's the only one they make, but I might be wrong.
As for accuracy, if you need to know EXACTLY what your A/F ratio is in ppm, get a scantool or something. Most gauges arent 100% accurate for anything, they just give a general idea.
Don't know about the voltage band for our O2 sensor, but my gauge behaves exactly as the instructions said it would, reading the correct lean, stoichiometric, and rich levels.
IP: Logged
01:13 PM
1FST2M6 Member
Posts: 3905 From: Dallas, GA. Registered: Jan 2000
i like my haltech unit. air/fuel and injector duty cycle. bit over $100 shipped.
mine working.. the car was cold so it's slow to react.. but within 2 minutes of the car running it's reading juuust fine... if you get a heated O2 it'll read quicker and the car will respond faster when cold... but thats not real a must. http://www.1fst2m6.com/images/1fstmonitorrunning.MPG
IP: Logged
01:21 PM
fastback87 Member
Posts: 300 From: Indianapolis, IN, USA Registered: Oct 2001
I also have the Autometer one and it works pretty good. It reacts a lot faster than my AutoXray. Range is 0-1000Mv in 50-100mv increments depending the range area. It will be as accurate as your O2 sensor. It's main use is to know if you are lean or rich at WOT. If you need to know exactly the A/F ratio then a dyno shop may have the kilo-bucks instrument to measure it. The good thing about this one is that for $50 it takes out the guess work about being lean or not on a modified engine.
------------------ Alex4mula :) Red-Original Owner & White-1/94 with PM (:
IP: Logged
01:46 PM
Neal Member
Posts: 1247 From: Calgary AB, Canada Registered: Jun 2001
The ECM and O2 is what's called a "bang-bang" controller. The O2 is only accurate at 14.7:1. It knows when the mixture is richer (higher output voltage) or leaner (lower output voltage) but not how much. The ECM just keeps the mixure swinging back and forth across stoich (14.7:1) and it averages out. At, say 12:1 AFR, one O2 might output 900mV whereas another might read 1000mV. Not very accurate.
Sooooooo, using the O2 to tell you anything really useful won't work. At the same time, if you are looking for a way to tell if something is really wrong, then the AFR meter will do that. You can see things like lean drop on a throttle stab, the enrichment from PE, decel cutoff, etc. Amazing what you can learn.
But if you want to know if WOT is at 12:1, it won't do that. You need a wide-band O2 for that.
IP: Logged
07:27 PM
Nov 6th, 2001
Leadfoot Member
Posts: 828 From: Schaumburg, IL, USA Registered: Jun 2001
lol.. yep..it's an aiwa.. i needed somthing cause i sssent my ssssony in to sssstop the ssssskiping... it's CDX-C910.
make your own? nope.. it'll take me 8-10 hours to make one or for $100 i can go buy one... is your time worth $10/hr? i just have one to make sure i'm not gunna destroy the engine under spray.. the apexi has 2 settings, n/a and switched (nitrous) it pulls 85% injector duty n/a and 72% under spray thats WITH 19lb/hr injectors. the a/f ratio is 12.8 n/a and stupid rich spraying those #s from the Competition Data systems logging equipment at EP. and their within 5% on the haltech.
------------------ 0-60 in 4.91
www.1fst2m6.com - underconstruction - but check it out anywho...
IP: Logged
09:17 AM
PFF
System Bot
Leadfoot Member
Posts: 828 From: Schaumburg, IL, USA Registered: Jun 2001
Does the haltech unit run off the O2 sensor? or does it have its own, and how does the injector duty cycle hook up? and finally where do you order it from? thanks
IP: Logged
11:53 AM
Nov 7th, 2001
Neal Member
Posts: 1247 From: Calgary AB, Canada Registered: Jun 2001
