Temporary install wide band AFR meter for carbs

[rbogh901]

Lots of AFR gauge threads. Many degenerate quickly into minutia/obscurity. Can someone speak to this, hopefully simple, request? Manufacturer's websites are frequently dominated by marketing/propaganda and vague.

Looking for temporary install to tune carbs. There's no ECU, no cat, no boost. Hobby level tuning. Therefore, I do not want to hardwire. Cigarette lighter install looks to be the answer to that. Is it solely for powering the gauge? Since this is a tuning aid, not a permanent gauge, can a laptop with a gauge graphic and logging replace the gauge all together?

What is the best/easiest way to source/log rpms? Why in creation would one need 32 channels to follow O2/voltage and rpms for a basic tune?

Exhaust clamp for sensor should eliminate welding bungs but then it sits up in there a bit. So, do they work that way? Do they burn sensors/wiring sitting in the exhaust path? How long a cable is needed and where can it run to get to the cabin adequately?


Some very respectable folks have provided some of the information here and maybe a thread has already covered this ground but most seem aimed at CIS, turbocharging, permanent install etc. Guys, some of us remain in the dark ages, (good old days), and don't have or want any of that stuff.

[1QuickS]

Before I permanently installed my AFR I installed a bung in the right side header, just after the flange to the muffler & ran the signal line through my right rear quarter window and used duct tape to keep it there while testing.

[kjchristopher]

Leaving the O2 sensor in the pipe without being hooked up will kill the sensor in short order. You'll need to get a plug for when you don't have it installed.

I've used a sensor from Innovate and just taped the wires watched the readout while driving. You could log as well, but that seems to be the harder way to me.

I've now installed an AEM gauge permanently. I've got it set up only to run the gauge. Again, just to keep tabs on what is actually happening in real-time and make adjustments as necessary.

Somewhere in the middle: Install the gauge and wiring (extremely simple - hot, ground and the plug to the sensor) and if you're dead set on not having the gauge in the car full time, just remove it and the sensor. If you leave the wiring, it will be dead simple to re-install and retune as necessary.

I use this one Analog Style Wideband UEGO AFR Gauge | AEM with the black face and bezel installed, primarily because I already owned it.

Another good option is this one if you prefer digital Digital Wideband UEGO AFR Gauge | AEM

For reference, I have an 82 911SC and run the stock CIS system on a 3.2SS with 964 cams. I adjust it a couple times a year as weather (or some other variable) changes. Again, my recommendation would be to leave it in and monitor your AFRs just like you monitor your oil temp etc. But if your don't like the look, just pull the gauge and leave the wiring tied up. Just don't leave the sensor in unplugged.

The kit I installed has enough wiring to mount the gauge where the ashtray was. I went in the tub near the tunnel. The temporary setup I had with the Innovate was taped to the outside of the car an in the sunroof. About a foot less cable than I really needed.

[gtc]

I just installed mine last weekend. Bolted it to the underside of the ashtray using a VDO bracket from NAPA. The install wasn't too hard... the worst part was figuring out where to run the wiring harness.



Unless you plan to use the gauge to tune periodically, spending some time on a dyno is probably cheaper and easier than data logging it yourself.

[Gordo2]

I recommend installing something permanent - you won't regret it.

The permanent install will let you get to know how your carbs respond to various conditions - and help you figure out how to configure them to suit your engine and driving preferences.

Go with something simple that takes RPM and AFR and provides convenient data logging and good app for playback.


Gordo

[rbogh901]

The recurring theme, reading between the lines, is that my original questions are at least partially invalid. Temporary installs are not even on the radar with these replies. Paul, KJ, Graham and Gordo, that's 4 for 4, all indicate that a permanent install is the way to go. I've followed Gordo's very excellent thread and can see the value of this kind of analysis.

If I were to restate my question and ask does a temporary install, say for a few weeks or months, permit adequate tuning is the answer no? Are Weber/PMO/Zenith folks tuning and refining their tunes endlessly? Do they become fond of the extra level of awareness to the point that they make it a permanent display? Or do they use the gauge as a monitor to avoid possible disasters?

Anyone who has had an AFR gauge for more than a year care to mention how often they use it to adjust tuning vs monitor for possible damaging conditions?

[Gordo2]

Adequate tuning in a couple weeks to a month is absolutely do-able. Once I had mine reasonably tuned (no concerns of leaning out) - I left them alone and ignored the wideband for 6-8 months.

Also, once tuned to my satisfaction (no concerns of leaning out) I prefer not to glance at the wideband display while driving - it can distract me from an otherwise pleasant drive.

Go with what you think will suit your interests
- If you like to tinker with your car, and have a serious interest in learning about your carbs and how they work, and interests in optimizing them; no question - get a permanent install.
- If you want to set them up once and forget about it, go with a temp install.

For the cost of the temp install though I think you could get your carbs set up adequately simply based on using normal/recommended jetting and then hit a few dyno runs to confirm (many places charge ~ $100 for 3 pulls / no tuning support just the pulls).


Gordo

[dicklague]

No one mentioned installing the wide band sensor in the exhaust with an adapter. In my experience it just does not work. Maybe at idle.....but when you start driving the air around the exhaust dilutes the reading. I have never made it work.


Weld in a bung. If you take the sensor out after a while put in a plug.

My best setup has been a map sensor with a Daytona-Sensors WEGO IV. 2 hours of data logging and good software and a high quality unit. Also sold by our hosts here.

I agree that you need logging and some time to analyze your tuning.

[fred cook]

When I built the 3.3SS engine for my SC, I installed an AFR gauge to help with tuning the CIS injection. Once that was done, I left the gauge in place but only refer to it occasionally just to get the warm fuzzies that everything is still working correctly. At some point, I might change over from CIS to ITBs and will need the AFR again at that point. I will agree that running the wiring was a bit of a pain but well worth the effort required! To answer at least one of your questions, you could install and wire the gauge like it was going to be permanent and then remove the gauge only when done with your tuning. That way it would be gone but easily re-installed if needed. Good luck!

[Vereeken]

The easy way is the Innovate LM-2 .

I still have a LM 1 and use it now and then. You have to order the exhaust bung. It goes deep enough in the tailpipe to get an accurate reading.
As you said I can write pages on Delta measurements between hard wired and temp wired, but that is nitpicking. the AFR reading at IDLE is good enough for home tuning.
Once at speed it even gets more accurate as the exhaust gasses push out all air and make the reading even more accurate.

It is not entirely true that an unpowered 02 sensor goes wrong very quickly.
This is only true if you hang it up side down in the tailpipe and you allow condensation fluid to touch the bung. Solution is to install right way up so that water can not touch sensor.

[Damon in STL]

When I installed EFI on my car I used the LC-1 from Innovate Motor Sports. I welded it into the SSI header on the left prior to the muffler. You can use a laptop to log AFR and get a decent base tune. Depending on the different ambient temps you may see throughout the year you may want to pull out your laptop, re-install the sensor and, verify/tweek your tune.

I also use the LM-1 on my BMW race car with MegaSquirt (911 has MS also) and periodically re-tune.

Damon

[bpu699]

You can buy just about any AFR meter, jam the O2 sensor up the tailpipe a foot or two, and run the car... Or, just temporarily replace the current O2 sensor (if you still have one). If you are looking for temporary. You can hook that up to any loose 12 volt battery you have laying around the garage.

Pretty simple.

They also have AFR meters that send the data to your cell phone ($)...

[gtc]

Originally Posted by dicklague

...
My best setup has been a map sensor with a Daytona-Sensors WEGO IV. 2 hours of data logging and good software and a high quality unit. Also sold by our hosts here.

I agree that you need logging and some time to analyze your tuning.

That looks like a nice setup. I like the dual sensor version. Pretty cool.

[rbogh901]

Originally Posted by Gordo2

Adequate tuning in a couple weeks to a month is absolutely do-able. Once I had mine reasonably tuned (no concerns of leaning out) - I left them alone and ignored the wideband for 6-8 months.



For the cost of the temp install though I think you could get your carbs set up adequately simply based on using normal/recommended jetting and then hit a few dyno runs to confirm (many places charge ~ $100 for 3 pulls / no tuning support just the pulls).


Gordo

Thanks for your insights. Yes, I've considered pulls but the reality is that, as in your case, a couple weeks/months of real world data would be far more revealing and $100 per shot quickly pays for a nice wideband system. It sure helped your tune so it's hard to ignore.

[Mark Henry]

I've done it many times, through the window method usually. I've done carbs, stock FI, aftermarket FI. I pick up 12V usually off the fuse panel, you want a good clean connection. I stick the ground wire under a bolt on the shifter.

First off I've never datalogged my A/F meter, even though I could.
I'd also never install it under the dash, etc., I want it up high in my line of sight.
An AF meter is instant so as long as the engine is hot you are good to go on accurate tuning readings.
For my 914 and my 1967 bug I have a modified old ashtray as a mount.

Weber carbs only have 3 circuits, since I've always started with carbs jetted for a 2.0 you for the most part are going bigger for a larger motor.
I have a handy set of carb jet reamers.

First the carbs need to be serviced, balanced and the linkage has to be perfectly adjusted.
Then I drive around and I'll stop, even on the side of the road, pull the jets and ream each jet to the next size. Then drive, watch my meter and jet, repeat till you get what you want. You are looking for a perfect AFR under load, through the 2nd and main.
On decell the AF meter goes crazy lean, don't worry about that as it has no load.
If you have to go down in size of course you'll have to order them.
Now some of this is also tuning experience working here as well, but if you take your time it's not too hard to do.

Ashtray mount in my 914 with SDS EFI on my old 4 cylinder. I am just finishing up a 3.0 weber six for it now.

[kjchristopher]

Couldn't find anything specific on Bosch's website, but here is an excerpt from the AEM instructions using the Bosch sensor. Your mileage may vary.

Notes
The sensor contains a ceramic module and should not be subject to mechanical or
thermal shock or it may be damaged. The sensor is not designed for operation on
leaded fuels, doing so will dramatically shorten sensor life. Long term running in the rich
region (Lambda < 0.95) will shorten sensor life. High exhaust temperatures (over 850C)
will shorten sensor life. Engine oil consumption at a rate greater than 1 quart per 1,000
miles will shorten sensor life. With the UEGO Sensor installed, do not run the engine
without power applied to the gauge.

[rbogh901]

Originally Posted by bpu699

You can buy just about any AFR meter, jam the O2 sensor up the tailpipe a foot or two, and run the car... Or, just temporarily replace the current O2 sensor (if you still have one). If you are looking for temporary. You can hook that up to any loose 12 volt battery you have laying around the garage.

Run it up the tailpipe 2 feet, wire and all?

No current O2 sensor. 1972 911 with Webers.

Loose battery? So put it on the passenger floor or garage floor for stationary tuning?

[bpu699]

Yep. You can run it off a loose car battery on the floor...

You can leave the muffler off and tune each bank separately I would think....

[Mark Henry]

Originally Posted by rbogh901

Run it up the tailpipe 2 feet, wire and all?

I wouldn't run it up the tail pipe, O2 sensors are not that cheap.

Weld in a bung or make a temporary extension like this one:
http://image.corvettefever.com/f/corvette-parts/fast-ez-clamp-on-tailpipe-wide-band-sensor-mount-kit/17868366/fast-ez-clamp-on-tailpipe-wide-band-sensor-mount-kit.jpg

[rbogh901]

Very good. I've thought that placing the sensor at the tailpipe was unsatisfactory because of poor readings and installation problems so the bung probably makes sense.

Using a small 12 v battery for power is an interesting idea. Quick, easy, have to be careful though.

Readings may not need logging, just real time observations, although I think Gordo's data was nice for him to review later. I'm fine with taking the laptop when needed.

Running the wire to the sensor is quickest, easiest through the window. How about through the shift coupler cover into the cabin?