Air fuel meter question

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d55dave

d55dave

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I know very little about air fuel meters....... but can see how nice they would be to properly jet and set up a carb and have often thought about buying one.

A coworker of mine has this one for sale, lightly used, for $200 CDN.

Is this a decent meter? What are they worth used?

This one is set up to use with a bung but can apparently be used with a tailpipe mount as well.

Thanks for any advice.

IMG_20171102_123200.jpg
 
d55dave said:
I know very little about air fuel meters....... but can see how nice they would be to properly jet and set up a carb and have often thought about buying one.

A coworker of mine has this one for sale, lightly used, for $200 CDN.

Is this a decent meter? What are they worth used?

This one is set up to use with a bung but can apparently be used with a tailpipe mount as well.

Thanks for any advice.

View attachment 1715106957
Click to expand...

IMG_20171102_123205.jpg
 
I bought their DLG-1 dual sensor one to tune my build im doing, dont have the car running yet but great products, have known people who had them and also AEM has a good quality one as well, had one of theirs on my srt4.
 
Compare price with a new LM-2.
The LM-2 is smaller and slightly more user friendly.
The LM-1 requires a serial port on your computer. USB to Serial can be done but some work and some don't. You can dig into the archived posts from the closed Innovate forum if you have to go this route.

An AFR gage is most useful if you can record rpm. For part throttle tuning, vacuum and/or throttle position are very helpful. The LM1 and LM2 can be chained to auxilery box to do that. The LM2 may have rpm built in - I forget.

Innovate's system is good with respect to response time, the fact that the Oxygen sensor calibration can be checked, and it will give an error when things are out of wack.
Innovate's software can be downloaded free, so you can check it out. There is a learning curve - its not the easiest set of instructions to work.

How it works -
AFR is a derived measurement. The Wide Band Oxygen sensor responds to left over oxygen in the exhaust with a voltage signal. If everything is burning as expected, its fairly reliable method. The voltage is converted to "Lambda" and then lamda is converted to AFR for gasoline (if you want) based on the assumption of stoich is 14.7:1
Or you can just use lamda and not worry about what fuel you're using. That's easier for some people than others. LOL
 
USB/Serial port is hit or miss. I installed a serial port on a laptop that didnt have one: I replaced the VGA out with a DB9 serial port (same size) and ran some very small wires to the MAX232 chip I found on the thinkpad motherboard. works great! I have a Summit Narrowband that I have not even opened yet, sort of useless.
 
So.... my intent is, and perhaps I didn't realize just how complicated this can be, to be able to drive around and record (by writing if I have too, i dont care too much about charting on a laptop) the AFR througb all different driving regimes. With this information I can then adjust idle mixture, main jets and accelerator pump shot in order to optimize the tune.

Am I out to lunch?
 
It looked too complicated to me so I bought the AEM Failsafe datalogger where everything is built into the gauge itself. Very easy to mount and wire. All I do is connect my laptop to the gauge through USB and download 2 hours of data. WISH THERE WAS A RESET BUTTON ON THE GAUGE! Kinda sucks having to search through the log for my run.
 
d55dave said:
Am I out to lunch?
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Possibly, but that's a discussion for another post. :D

Anyway, I have the MTX-2 set and it works great and has for years now.
The gauge is mounted in my gauge pod so it's right there in front of me with a readout all the time.
The MTX also has a data port, but I don't use it for logging.
I just drive in the conditions I have a question about and see what the gauge says then go from there with any changes or adjustments.
Since the gauge reads immediate changes it makes it easy to see where thing are as the engine transitions for idle to cruise to WOT.
Personally, I think you would be better off with the MTX if you are buying one anyway.
I think mine was around $130 or so US.

The MTX also has error code readouts, like low voltage codes right on the gauge.
This one saved me once where a field wire broke loose one night on my alternator and I was able to find and fix it before the voltage got too low.

Just don't get all caught up in perfection of numbers, as it will vary a bit with temps and elevations and chasing that constantly can drive a person who is the least bit anal about things crazy.:D

innovate-MTXL__26967_1330526287.jpg
 
d55dave said:
So.... my intent is, and perhaps I didn't realize just how complicated this can be, to be able to drive around and record (by writing if I have too, i dont care too much about charting on a laptop) the AFR througb all different driving regimes. With this information I can then adjust idle mixture, main jets and accelerator pump shot in order to optimize the tune.

Am I out to lunch?
Click to expand...

H'm. Better stay safe. I'll agree with TB. We can discuss whether you are out to lunch in a different thread.:p:D

OK. Seriously. A gage will be much easier to read, video, or have someone read while you're driving. The LM1 is a logger first and foremost. The LCD is not that easy to read - even on the dyno and its hard to place so its next to a vac gage and tach.

Noting the AFR simply provides a reference point. You can use it to figure out f whether the change you made had an effect on the area you are tuning. You can also establish some limits for your specific vehicle. The only time the exact number matters is emmissions. Economy, efficiency and power will be simply be the number that works best - don't try to tune to an AFR number. Tune for power, response and economy.

So what that means is you can do that without an AFR gage. Best MPH in 1/4 mile will be power. Leanest primary jetting without surging will be the most fuel efficient on the interstates. Idle screws are mostly about curb idle - do that by vacuum gage in gear. Pump shot - this happens very fast. it still has to be done by how the car reacts.

When talking about any situation that's changing rapidly, like pump shot, observing and writing down is not very practical. Everything happens in less than 2 seconds, really less than that. Think about how fast a car launches at the drag strip! This is when a fast responding logger is helpful.
 
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The OP is doing himself a favor to use an AFR. It is almost like cheating! We have the Innovate product and it seems to work quite well. If the O2 sensor ever dies, it is a standard Bosch sensor with a specific pigtail/connector.

If you don't want the data logger, just ride along with someone else driving and have them go through certain acceleration procedures, and record it by hand. Watching the gauge as I feel the car accelerate tells me a lot more than trying to read a recorded layout later.

Also, don't use AFR reading to set engine AFR when cold. The AFR will read lean; it is the result of unburned fuel not consuming the oxygen in the combustion process as it should, and that results in excess oxygen in the exhaust that the AFR shows as being lean. So don't make sure you have the engine completely warmed up before counting on AFR readings.

Also don't get focused on the stochometric ratios when in light cruise; AFR's can read a bit high, in the 15's and bit into the 16's under those conditions and all will be fine.
 
nm9stheham said:
The OP is doing himself a favor to use an AFR. It is almost like cheating! We have the Innovate product and it seems to work quite well. If the O2 sensor ever dies, it is a standard Bosch sensor with a specific pigtail/connector.

If you don't want the data logger, just ride along with someone else driving and have them go through certain acceleration procedures, and record it by hand. Watching the gauge as I feel the car accelerate tells me a lot more than trying to read a recorded layout later.

Also, don't use AFR reading to set engine AFR when cold. The AFR will read lean; it is the result of unburned fuel not consuming the oxygen in the combustion process as it should, and that results in excess oxygen in the exhaust that the AFR shows as being lean. So don't make sure you have the engine completely warmed up before counting on AFR readings.

Also don't get focused on the stochometric ratios when in light cruise; AFR's can read a bit high, in the 15's and bit into the 16's under those conditions and all will be fine.
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I totally agree on all points.
The AFR only really shortens the curve from running ok to running good and clean.
WOT plug readings, mid throttle response and idle quality can all be addressed a lot quicker than trial and error methods.
I also agree about chasing numbers and what you can actually get away with.
My motor runs up in the high 15's-low 16's at idle and light throttle cruise, then drops into the low 12's or high 11's at WOT.
2000 feet lower elevation and all those numbers are a full point higher. (leaner)
 
cheap Data logging...use a gopro at your dash and have a vacuum guage next to the AEM (as well as a TPS readout and a temp) or just have a running commentary on what you are doing : floored acceleration, deceleration, braking, cruise, idle, passing, etc.
 
Great points and info, thanks for all the input.

I usually rake the leaves this weekend. I cant as there is about a foot of snow on them and it is well below freezing. I have had enough of winter already, LOL.

I have never had an issue with getting a carb to run good but honestly dont have the time to spend at a track making repeated passes, swapping jets, reading plugs etc. to try and optimize the carb. I guess that I will have to wait for spring to play with it!

Cheers.
 
pishta said:
cheap Data logging...use a gopro at your dash and have a vacuum guage next to the AEM (as well as a TPS readout and a temp) or just have a running commentary on what you are doing : floored acceleration, deceleration, braking, cruise, idle, passing, etc.
Click to expand...
Good point... I have a vacuum gauge hooked up too. It is great indicator of where the throttle is, and you can tell things about the power valve action. I never thought about a camera to capture the info, but that is a clever idea.
 
nm9stheham said:
Those are good AFR numbers IMHO for a general all-around street engine.
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The only issue I think I may have solved that today when I did a flush and re anti freeze of the cooling and heating system.
When I stuck the throttle hard it would sometimes go lean to the high 18-19 and pop back through the carb a little until it caught, so I set the accelerator pump on it's highest leverage setting and drilled the squirters out .004 bigger.
We'll see on the next test drive.

Yep, got it.
I went 2 steps heavier on the step up springs and like I said, drilled the shots out and the hesitation on quick step in was nice and strong with an AFR of the low 13's
 
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