OBD2 tool
 

I'm slipping further and further into nerdity:

I've been looking at laptop-based OBD2 tools because the SG1 isn't giving me all the info I want to see. Specifically, I want to know about fuel trim, since that's something that would be affected by HAI and EGR. But fuel trim is one parameter that the SG doesn't offer.

Also, I'll be able to log & graph relationships between sensor readings, whereas the current SG 1&2 only let you view "instant" data, which is actually pretty useless if the reading changes frequently by its nature (e.g. timing advance, throttle position, load etc.).

I realize the SG2 is supposed to have a USB or flash media logging feature coming out, but I don't know if it will include ALL parameters, or just the ones currently accessible (e.g. no fuel trim).

Anyway. There you go. Data geek!

Hey ,, your bustin in on my ideas.
Get behind me nerd. !
https://www.davidmsc.com/wp-images/nerd.jpg

I'll be very interested to hear if you find a package that works well. The ability to collect and analyze data for an entire run would do wonders for our understanding of what these machines are doing.

This is the kinda stuff like they use in shops or the kinda stuff like they sell to nerds? The shop-based stuff is prolly the best EFI tool imaginable, in my mind.

I don't think it would work on your car but I have been running vag-com
https://www.ross-tech.com/
for a while. It lets you change a LOT of things on the car, like how the doors lock, to engine timing to real-time MPG and LOTs of logging. I really like up, but it is a pain using the laptop all the time. I was so glad when SG came along.

Hey doesn’t the new SG2 have a USB out and logging options?

I don't think the Metro ECU is programmable.

I agree: the convenience of the SG is not in question. But sometimes I NEED MORE DATA. :)

SG2 is supposed to be coming out with a logging /export feature, but again, I don't know if it'll include all the sensors & engine parameters. It's missing a few now, in both versions.

So metro, which tools have you looked at? I'm curious how you connect the obd2 to the pc (I know there are a adapters out there) and then what software? TIA.

Well, turns out this isn't the first time I've "decided" to get one. Check this thread from January and you'll see a few different types mentioned.

https://www.gassavers.org/showthread....ght=laptop+obd

Other than those, I'm considering one of the generic ones from Hong Kong. Cheaper, but probably hard to get service if it dies :)

Nerdy, eh? Well then the line forms behind me! I have three different datalogging programs loaded onto two Palms! I personally don't think of them as nerdy since they are essential tools for improving the 1/4 mile capabilities of my cars. The simplest program show about 20 different gages. The more complex loggers are customizable so I can export any address in the ecu to the logger and see what it's doing. I couldn't tune without them.

OK I'm bragging a little, but I still don't have one that outputs instantaneous mpg :( so I'm still flying blind!

Sweet
 

IIRC, from that thread, there should be some free-ware applications this setup -- all you would need is the cord.

BTW, great decision! I think a lot of us have been dreaming of one for a while ;) Keep us posted, and good luck!

RH77

Yeah, as RH77 says, my understanding is there are freeware programs that can calculate instant/average MPG from any OBD2 interface.

Someone on teamswift is using this tool. Inexpensive, and he says it does MPG instant/avg, short & long term fuel trim: $83 + $5 shipping.

https://www.obddiagnostics.com/order.html

You can also order it in kit form and solder it together yourself if you're able and want to save more $.

Looks like the MPG feature is part of the freely downloadable interface you can get here: https://www.obddiagnostics.com/ProgWin.html (Windows ver). Maybe this'll work with your existing physical interface. Worth a try.

Just downloaded and installed the software from the link above. You can operate it in "simulation" mode without the hardware (random values).

Pretty neat. But I can see how I'd like to improve it already.

It does have an instant & averager resettable MPG function, based on either MAF or MAP output. But this function is pretty basic compared to the SG, and I'm not sure it can be fine-tuned (e.g. distance & fuel used calibration).

The guy who sells/writes this lives in TN. I bet he'd make some cash if he got involved at GS and expanded its MPG functionality. He could be a real competitor to the SG2.

asdf

I just won an auction for the Hong Kong unit

I really like that laptop setup. Only problem is now you are going to have a real hard time looking at the road. You cant just put the laptop on your dashboard.

You're right. Now I need a dynamometer!

Thanks for the tips and links. Unfortunately my cars are OBD 1. I'll keep looking for something with a MPG readout. As a closely related substitute, I have a MAF readout on my dash so I can see instantaneous consumption of air, which is closely related to fuel consumption as you know. I did a quick experiment with it one day- I was cruising on the freeway at a constant 65mph and noted the airflow was about 150 Hertz (it's a frequency based airflow sensor) Then I put the car in neutral and revved the engine until it showed 150Hz again. The revs stabilized at 5300rpm. So it takes just as much fuel to push my car down the road at 65mph/2400rpm as it does to spin only the motor at 5300rpm. Blew me away. I was a believer in shifting at low rpm after that.

I wonder what sort of tests MetroMPG will come up with using his new logger? Any plans yet?

BTW one of my loggers is called Pocketdyno because it has a built in dyno program. Yes, it's cool and yes, my loggers are all 1/4 mile oriented.

Getting a standalone would of done the same thing with your mileage. It's a computer based system and it fine tunes so good that one of the side effects is better fuel economy. You should of just gotten a megasquirt.

- It'll let me look more closely at things like my hot air intake.

Thanks for posting the links. In the first link to the WAI test you said,"Why doesn't it show up in the results? Perhaps because:

The throttle is open slightly wider, and the effective load is higher. The ECU may be compensating by enriching the mixture."

There is a direct link between engine load and timing. As load increases the ecu will reduce timing. This could be why the WAI didn't work, you had to open the throttle more and that put you down on a lower timing level. So what's more efficient, a stoich mixture with high timing or a lean mixture with low timing? The answer lies in your datalogger.

What would be really cool is if your logger lets you analyze the data in a statistical way, like a 2 way ANOVA. That way you could plug in IAT on one axis and anything else on the other axis and see if there is any correlation. How about IAT vs. fuel trim? IAT vs. O2 readings? Or?

You said it, man.

Sorry. What the heck's ANOVA? Edumacate me please.

ANalysis Of VAriance. It's a statistics term. It lets you see relationships between two variables even when the two variables are constantly varying. :D
Clear as mud?;)

Makes sense.

Stat Progs
 

All I've used in such an application is SPSS for stats. Is there recommended freeware out there that will run statistical applications?

RH77

I'd love to have some SPSS freeware.

---

Got e-mail from the seller: unit shipped this AM air mail. Should have it in 7-14 days. The only unknown is customs fees. That's always hit & miss with international packages. Sometimes I get hit, sometimes I don't.

Hi MetroMPG -¨Sometimes I get hit, sometimes I don't.¨

Consider yourself lucky.
Here every non EU package will get taxed , even gifts from relatives if the customs dept think the value is over $20., and because postage is added to this valu'ing method it means almost everything gets taxed.

Not that I'm aware of. One of my loggers includes a neat graphing function where I can plug in any two variables and see where each datapoint lies. I find it helpful when looking for relationships between two variables as the datapoints tend to form clusters, lines or scatter. I tried to get a screenshot of it last night, but the log viewer doesn't seem to support it.

I have a feeling the new OBDII logger will give you plenty of data to crunch. Some sort of statistical tool can be useful if the data becomes overwhelming.

Nerd alert update: OBD2 tool arrived. I'll hopefully give it a try this evening and report back.

I saw the same tool sell for $10 less on eBay this week ($45 shipped). So if it works, might be one to watch for.

EDIT: PS, didn't get hit with duty. Nice.

Can't get the laptop to see the tool. Hrm... I've got LEDs showing on the tool when stuck in the OBD2 port, but I don't know what they mean (no instructions came with it).

I wrote to the seller for advice. This is the part where I discover if I should have paid more for the one made in TN...

I think it's the computer - the COM port isn't active - tried connecting a serial mouse and a digital camera with no success for either.

Anyone have any suggestions on how to diagnose it? I've been messing around and not getting anywhere. Win 98 on an old p120 laptop. Device manager says the serial port is enabled and working properly...

OK: I'm officially disappointed with the tool I got.

I finally got it "working" with a borrowed computer (with a known working COM port).

The unit came with half a dozen free OBD reader programs on a CD. Only one of them works with the unit, and it doesn't have logging, graphing, or gauge functions. Useless.

So, now I'll have to look around for a better program.

Does that mean you're OK with the hardware and not the program, or do you think you're painted into a corner with this particular hardware that has sub-optimal sfw support?

I just don't know enough about the hardware to say it's "good" or not, or whether it's only a hardware/software compatibility issue.

Reading around online, I have learned that not all the programs work with all the hardware, despite supposedly being built on open standards.

Essentially I bought hardware built by hobbyists, and am attempting to run it on software written by hobbyists. In retrospect, the smart move would have been to get both pieces of the puzzle from the same hobbyist (like the guy in TN, whose program screen shots I posted above).

For all I know, it may be computer-related too.

Metro: do you know if there are any open-source programs out there that would work with the hdw you have?

I believe the source is available for some of them, yes. The one that came on the CD with source coded didn't work on the borrowed computer, though. Locked up.

Depending on what language the source is written in, you might be able to make your own mods to it. I think that's what I'm looking for, though it's always nicer to find it already written and stable. And of course if it works and you have the source, it (or part of it) might be ported to other platforms like Palms and cel phones. Maybe.

It would be very good to be able to do that, yes. Beyond my capabilities though.

I've spent too many hours trying to make this work over the last 2 evenings and I've run out of patience. Time to put the toys away, close the laptop, and chill.

Spent another hour plus on it today: Re-installed EVERYTHING on my old laptop (so I can give the borrowed one back) and got the COM port to talk to the scan tool. And I think I found a program that will do logging, and it also appears to be able to talk with the tool.

I'll have to look into it a bit more this weekend. Quel grand ordeal.