I'm shopping for one, who makes the best dual input style? Not shopping price, shopping quality and ease of use. This will be set up on an engine run stand, not installed in a car.

If you are going to use the run stand a lot and you need to depend on the numbers for carb calibration or tuning then I'd get dual gauges. Put a separate gauge on each side of the engine. It will cost a bit more money but then you'll have a redundant system. That allows you to check the gauges to see if they are reading the same and it allows you to keep running if one gauge goes on the blink. Use the same exact make and model gauge on each side so you can swap O2 sensors from side to side. I'd also shop for a gauge that uses an industry standard O2 sensor so you don't have to pay thru the nose to buy replacements.

I hadn't considered that Andy, thanks!

I like this one.
https://www.innovatemotorsports.com/products/lm2.php
It uses two sensors, has display for viewing, records the measurements, lets you record to a SD card so you can save and playback. does gas and alcohol. I use one on our engine dyno at school.

If your going to test alcohol carbs get the good NTK sensors, not Bosch

Why? I run both NGK/NTK and Bosch and the only difference I can see is the NGK hold up to leaded fuels a little better. On methanol (which is about 25% of my customers) I see no difference.

Joe

Innovate lm2 works great as mentioned above. If you read reviews the only people that usually have issues are using the cigarette lighter plug. I hooked it direct to my car 12 volt wiring for clean power with a plug. Nice unit.

Scott, If you're considering the Innovate products, then see if a setup with more channels might be a better investment.
Something like the SSI-4 or LMA-3 combined with a logger and WBO2.
Having MAP, TPS, and rpm with the WBO2 will give a most complete picture.
https://www.innovatemotorsports.com/products/pl1.php

You can set up an older laptop to watch everything real time as well as logging.

Before buying, download Logworks and see if you like the way it feels and learn its quicks.
https://www.innovatemotorsports.com/support.php

If you need sample/examples in addition to what may come in the download, there's some at RFS as attachments. Or just ask, and folks can e-mail you theirs.


Innovate stuff has a learning curve and the instructions are more like what you find in industry where they assume the buyers have some datalogging background. So its not for everyone, but it is good product for the price range.

Another vote for Innovate.

Just follow the instructions TO THE LETTER and you'll have no trouble.

Kevin

I have had the Innovate LM-2 for several years and am in the process of getting the MTX-L guage and PL-1 pocket logger so I dont have to keep the LM-2 in the car un mounted, as said above they assume you have prior experience with this type of electronics,,I don't and it has taken me a while to learn the basics,, the new equipment will make things a little easier and a tidier set-up.

One thing I just realized is that being on a test stand there will be no load. May limit what can be learned

Yes Mattax, pretty much will be just to get more accurate mixture adjustments, I already have a vacuum gauge and a tach which works just fine but going to the next level never hurts . I'll likely use it to tune my cars too so it will get used elsewhere as well.

You probably know this but you will want to make sure you have plenty of pipe after the 02 sensor or else it can pull some fresh air back in and skew the readings.

My car has full exhaust but it has exhaust dumps not to far from the 02 sensors. When they are open the 02s read full lean until at least 2500RPM or so. My car also has a big roller cam with lots of overlap which I am sure doesn't help. They function just fine in the mid range and above but don't give any data at idle and low engine speeds.

MY THOUGHT EXACTLY

A CO meter might provide a better indication AFR than a WBO2 when working on idle.

Don't get me wrong, its great to be able to log Vac, rpm and AFR (or lamda). I plan to add TPS at some point. But left over CO seems to be less subject to variations in combustion temperature and other phenonmenon that can fool an AFR based on left over O or O2