Nerd alert! Think I'm going to get laptop-based OBD2 tool -update: ordered & success!

[MetroMPG]

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!

[MetroMPG]

BTW, 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.

[MetroMPG]

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

http://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 $.

[MetroMPG]

Just downloaded and installed the software from http://www.obddiagnostics.com/ProgWin.html . 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.

[MetroMPG]

[MetroMPG]

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

• - It'll let me look more closely at things like my hot air intake. I've never been satisfied that my HAI seemed to produce no favourable results, because the theory is sound. With this unit I'll be able to see immediate changes (if any) to timing advance, throttle position and fuel trim and maybe answer the question as to why it didn't appear to work on my car (and maybe make it work).

• - Same thing with adding more EGR. I could theoretically idle the car in the driveway, run a hose from the tailpipe and introduce exhaust into the intake and watch the sensor results live.

• - Last winter I was also talking a bit about spoofing the coolant temp sensor to achieve closed loop operation a little faster. This would let me view and log the results of that.

I'm sure I'll come up with more things to play with once I see what it can do...

[MetroMPG]

just won an auction for the Hong Kong unit, same as:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=011&item=320035379243&rd =1&sspagename=STRK%3AMEWA%3AIT&rd=1



Total with shipping: $55 USD.

Had I lost, I would have ordered the same model described above that the teamswift guy uses.

Should have it in 2 weeks.

[MetroMPG]

HW/SW compatibility issues...

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.

[MetroMPG]

Finally, after ... 1 borrowed & returned laptop to confirm the tool was working; 3 OS re-installs on my old serial-port equipped laptop; half a dozen freeware/shareware OBD2 software installs & tryouts (they didn't all work); multiple e-mails back and forth with the tool vendor (was quite responsive and helpful):



Edit: cold start, trip around the block. The only downside: the programs that work with this tool and provide logging ability don't also report fuel consumption. So the SG will be a little out of whack when I disconnect it to do trials with the ODB2 tool.

Data exported as a text file, imported into Excel to use the charting utility. Dressed up a little further in Photoshop.

[MetroMPG]

I like being able to view fuel trim with this tool.


Fuel trim is the mystery variable behind the EGR fuel savings theory. It's where the 02 sensor data goes: constantly into Short Term to maintain stoich. Short Term, when it maxes out in either direction, informs Long Term and then resets to 0 to start all over again.

More details about fuel trim:
http://72.14.203.104/search?q=cache:...n&ct=clnk&cd=4