Look for "The Cheap Way" about 2/3 of the way down at... http://www.bob2000.com/carb.htm He is hooking up an O2 sensor into his exhaust pipe, and hooking it into a digital volt meter. Anyone done this, and does it work as well as he says?
What's new? It's aways been done that way. Any gage that reads the voltage out of those sensors is a voltmeter, just may have a different way of representing on the face of the gage. Either in terms of voltage or just colored areas in the gage face in analog or Led colors change. Next thing is you need to interpet what you see for readings off a voltmeter. On a carbed motor, if you can't relate to throttle condition because it has little value from a narrow band sensor. On a fuel injection motor, it's value is very limited except for certain functions that would only be useful for disgnostics and to feed info back to the computer for correct air/fuel ratios at light load running. The OX sensors used are of little value if they are the standard narrow band types and will not tell you anything accurate about wide open throttle operation, so are not useful for that kind of tuning. Your link friend is using a narrow band sensor and wants you to buy his book.
The NARROW BAND such as the Edelbrock is pretty to look at and will let you know when it goes lean.( TOOO LATE). If you are serious and want to tune with one GET the LM1 from INNOVATE. It is about the cheapest wide band out there. DONT take a chance on using something that you cant calibrate.
This is what happens when you try to enlighen someone! Bought, one thumbs up. Ignorance is bliss until they find out different. Wide band equipment is the only worthwhile type to use. The engineer in the link isn't telling about that. A degree dosn't alway mean they are accurate! Right Scoop?
that narrowband sensor and digital voltmeter is a joke. It works, yes, but only at idle, part throttle. It won't accurately read A/F ratio below about 13:1 or above about 15:1 give or take. And we all (should) know that gasoline engines make the most power between about 11.5-12.5:1 A/F. The LM-1 is what I have my eyes on. It gives you the opportunity to actually log A/F, and combine that with the fact that you have the option of getting the RPM converter, you can display the A/F with relationship to RPM...and load it all into a PC to view later. It is a wonderful tuning tool...and in fact I am looking into getting one as we speak. The LM-1 is what is known as a wide band...it will read air/fuel ratios from about 7:1 all the way up to about 18:1 and accurately. It will also save the log, along with the capability of having several other input channels for other inputs....for say TPS voltage, MAF voltage, etc. Theres a lot that can be done with it! Yes it's expensive but you get what you pay for. Buy a $20 narrowband and you get a $20 tuning tool that is worth about $20. Not much by today's standards.
I was wondering if someone had used this setup and knew what precise mA would read what ratio in that area of the graph that would be difficult to interpret (where it jumps steeply), which happens to be the area that is most important to our tuning needs. Didn't read the entire article and didn't know he was selling any book or DVD. I was searching the net to find out if I could make an A/F meter out of a O2 sensor, and came across this. I guess the short answer is "Yes, and No"
Every time I've ever seen anyone on a car forum mention using a narrowband O2 sensor to tune a carb, everybody who's spent the money on a wideband has to shoot the guy down and talk about how the narrowband is worthless. That's just not true. Yes, the wideband is better. If I was tuning a highly modified or aftermarket EFI system, or trying to get another tenth of a second out of a boosted race engine then I would definitely want the precision of a wideband. But for just trying to get the rods/springs/jets right on a street car or weekend toy, the narrowband is better than nothing. It's actually pretty useful. At least as good as reading spark plugs and lots more convenient. I've used the same gauge Frank is talking about from Summit to tune an Edelbrock carb, and it was a huge help. I would probably still be tweaking it if I hadn't been able to at least ballpark whether I was lean or rich. And I really doubt I could have done much better with a wideband, given that the carb is hardly all that precise anyway. No disrepect to the wideband guys. If I could justify the cost I'd get one too. But can we at least admit the narrowband is a useful tool?
There is a big difference between a tuning tool and an accurate monitoring tool. I have an old exhaust gas analyzer that measures lean / rich mixtures and it is only slightly better than the narrow band O2 sensor if you have the time to let it settle. The O2 sensor is better than it when it comes to changes that happen during different conditions because it registers them almost instantly. With the meter I have to wait up to 30 seconds for any change to show and then another 30 seconds for it to settle in. It (the O2 narrow band sensor) is good enough to tune the main jets with and that is about as far as most will need to go anyway. I do wish there was a way I could stick one up the exhaust pipe and use it without making a permanent installation.
For street tuning a carb, a narrow band is plenty good enough. The only thing the narrow band won't help with is how far off you are. It's basically a yes or no gauge, which is fine. If you're off 3 steps on your main jet, then you might have to run the car 3 times to get it right. Not a big deal. I'll be using a wideband on my engine, because I plan to turbo charge, and not run any MAF sensor. So, the only feedback I'll be getting for the injectors is from the O2. The engine will also need to run between 10:1 and 16:1 between WOT and cruise. My plan is to use the MSII and an LM-1. Ignition duties will be handled by the EDIS8, so I will probably have to convert from COP to standard coil packs. That could be a blessing in disguise, because I can get some killer Hemi knock off valve covers. ...still just a dream right now...
This is a area where experience is worth more than what someone can write on paper or computer screen. The narrow band sensors are all but useless, They can only read between 14.1 to 15.1. I still have my narrow band sensors (yes 2, one on each pipe) The wide band sits next to them, There is no comparison. The narrow band sensors are slow and have a very narrow band. (more in the neighborhood of 14.5 to 14.9). The only reason they stay in the car is because they are the led bar graph and fun to watch. The LM1 is not nearly as expensive as a piston are a head. I haven't checked the price lately but when i bought mine the basic kit was less than 300.00 bucks. I have used it for years without so much as replacing a sensor. After the wide band was installed, After tuning i probably found more than 40 HP. Not to mention i get 15-17 mpg. Leave the narrow band to the people that don't know are care to learn to the difference. P.S. They also make a extension that slides in the tail pipe so you don't have to weld a bung in the system. (this is mainly for dyno use only).
