cheapest air fuel ratio gauge? (Page 1 of 2)

You really need a wideband if you're looking for useful information, especially WOT tuning.

I have one from Innovate. It works well, but cost a little money up front.

I have gotten handmedown innovate and AEM WBO2 gauges for our Lemons car... and they both needed new WBO2 sensors @ $50-70/ea.
I would avoid buying used UNLESS you factored in the cost of a new sensor in the deal.

While the Innovate LC1 is pretty cheap at $120, the AEM WBO2 sensors aren't that much more at ~$150 and come with an actual gauge.
Either solution allows for data output to an external logging system.

If I actually had to buy the gauges, I would probably opt with one that has as gauge.

PS. I think a WBO2 gauge has value even if you are carb'd; I remember seeing these used in a few roadkill episodes to make sure they weren't grenading their engines during drag runs (obviously they killed the engines in other ways).
PSS. I was also given a NBO2 gauge. Dumbest thing ever. "Rich" or "not rich" is all you'd get.

Agree that the narrowband O2 sensor won't really give you any useful info.

We have the Innovate LC-2 controller and their "DB" gauge with a digital readout - works great. Since we don't have an O2 sensor, the ECU uses a default setting for the mixture (we have an Audi with CIS-E). We usually spend more than a little time at each test day doing short runs and adjusting the AFM (set screw in the differential pressure regulator) to get the mixture on the rich side of stoich when warmed up and at WOT. You don't want to be running lean for any length of time.

The manual says to calibrate IN FREE AIR before using. They mean it. If you try to calibrate with the sensor installed in the exhaust pipe, it won't work correctly, found that out the hard way.

I have this and have been happy with it.
https://www.ebay.com/itm/Innovate-3796- … mp;vxp=mtr

+1 for analog

Why?
I have the digital innovate

with a turbo motor you really want a gauge. Because running a few laps lean before looking at your plugs can cause serious damage. Also from my experience with old bikes, reading plugs is highly dependent on the throttle position you were at when you turned the engine off. So it takes a lot of work to check WOT, partial throttle, and idle by reading plugs. Your idle and partial - 3/4 throttle can be in a safe region, but then that WOT could still be lean. Gauge takes all the guesswork out. (and driver aides like gauges are budget exempt)

slightly more data since I was distracted last night. I have the Innovate MTX-L (I think there is a newer MTX-L Plus now). Digital readout, but a simulated analog on the gauge face. Really easy to read at a glance.

newer version
http://www.innovatemotorsports.com/prod … l_plus.php

You are correct. I missed the details about old carb'd engine.

If you're simply trying to watch a lean condition, sure, a narrow band will work.

A wide band will tell you a lot more, but it's not necessarily needed in that case.

A narrowband o2 sensor is like having a binary fuel gauge. Is there fuel? Yes? No? It's only useful swinging the mixture lean and rich to keep a cat doing it's thing imo.

For the cost of an ok narrowband gauge and narrowband sensor you're around $100. For a bit more you can get a wideband setup that can give you useful info. Like maybe if you want to rejet it, how's it actually doing?

Also realize that wideband sensors drift a lot. AEM and a lot of the other fancy wideband gauges can not be recalibrated if the sensor drifts. I've seen AEM setups along with mxl? Read 10.0+ off from horribly drifted sensors. No hint at them being bad.

People think the innovate setups are finicky because they will throw a code for a bad sensor. Somehow they don't realize that's a very good thing to not blindly trust a bad sensor. The innovate can also be calibrated to a drifted sensor. Most others can't be.

To me, if you want to know, why not be able to see real info for a little bit more $? It will also be able to actually help you tune it when you want to.

About half way down, how a wideband sensor works.
http://www.innovatemotorsports.com/resources/news3.php

I have this one.
Wiring was straightforward. Since I got it used, I picked up a bung from Summit for $5 (add-on to one of my orders).
Apparently, there is some debate about just buying a BOSCH vs AEM part # for the replacement WBO2.
Considering the cost delta as $20 and I was only buying one of them, i just went ahead and sucked it up and bought the AEM part # replacement.

Other recommendation: set it up to tune for Lambda (not AFR).
Why?
the AFR for Stoichiometric combustion (stoich for short) for pure gasoline is different from E10 (what we have in CA) and E85. This can make discussions confusing as a target of 12.5 (slightly rich) will mean a different combination for pure gas vs E10.

A lambda of 1 is the stoich point no matter what fuel you use. This makes calibration easy (just aim for .77 to .85 Lambda at WOT).