Playing with OBD data

[cchase]

The problem with getting "more" sensors is that all of these systems (Torque, Ultragauge, Scangauge) only get the OBD2 systems. That's what has been so frustrating for me. I would like oil pressure and transmission temperature but they aren't generally reported, even though you know there are sensors and the ECU is processing that data.

If you got a manufacturer specific scanner you can get a lot more data, but they are obviously far more specific in application and usually thousands of dollars.

 

[dparm]

Originally Posted By: cchase
The problem with getting "more" sensors is that all of these systems (Torque, Ultragauge, Scangauge) only get the OBD2 systems. That's what has been so frustrating for me. I would like oil pressure and transmission temperature but they aren't generally reported, even though you know there are sensors and the ECU is processing that data.

If you got a manufacturer specific scanner you can get a lot more data, but they are obviously far more specific in application and usually thousands of dollars.



Not necessarily. For German cars, the cable and software is only a few hundred dollars. It gives you capabilities to "re-code" certain things beyond just reading sensors.

 

[dparm]

Originally Posted By: cchase
I think some vehicles pull timing during shifts, which could be something to look for.

That aside, some vehicles have strange throttle mapping. There's no way around it. Every BMW I've driven has very soft throttle response in first gear and immediately sharpens in 2nd and above, for example.



Yep. Most dual-clutch-equipped vehicles cut the timing between shifts (it's why it makes the [censored] noise).

Throttle response is not linear. If you dig around on the BMW sites, some of the tuners have actually graphed it. Same thing for the variable-steering assist. Both can be reprogrammed.

 

[Vikas]

Quote:
Not necessarily. For German cars, the cable and software is only a few hundred dollars. It gives you capabilities to "re-code" certain things beyond just reading sensors.
I suspect you are talking about not-exactly-kosher software here. You are not going to get factory sanctioned and factory supported hardware/software for that kind of dough.

 

[Hokiefyd]

I played a lot this weekend.

The Honda is cutting timing during shifts. The speed of the CANBUS on the Honda is impressive. Data response is immediate enough that the gauges look to be real-time, with instantaneous response to throttle position, load, fuel data, etc. I can watch it pull timing advance during the shift. Advance is usually in the 20-30 deg range before a shift, and it pulls back to about 4-8 deg during the shift, then back to where it was before.

I also filled with Shell 93 octane for this tank to see if the computer can tell that there's higher octane fuel in the tank. And it appears that it can. With the 87 octane from BJs in the tank when I first started playing with this, the highest spark advance I would get was around 40-42 deg. After about 50 miles with the Shell 93 octane, I saw a 50 deg spark advance, and the average highest for a trip is in the 45-48 deg range. More observation to come on that.

One PID I like monitoring is the catalyst temperature. It's interesting to watch how you can induce a 300 deg climb in catalyst temperature with just a little more throttle over a sustained period of time. Nothing new to those with EGT gauges. This is as close as I'll come to having an EGT gauge I think.

The Acura is a 2005 model and does not have a CANBUS architecture, and the refresh rate is very slow. It seems to refresh about once a second or maybe a bit more often. It's not really useful to try to observe because the data refreshing is so "blocky".

 

[Vikas]

do you have a link to your specific ELM327 adapter?

 

[Hokiefyd]

http://www.amazon.com/BAFX-Products-PIC1...p;keywords=BAFX

 

[dparm]

Originally Posted By: Vikas
Quote:
Not necessarily. For German cars, the cable and software is only a few hundred dollars. It gives you capabilities to "re-code" certain things beyond just reading sensors.
I suspect you are talking about not-exactly-kosher software here. You are not going to get factory sanctioned and factory supported hardware/software for that kind of dough.



Correct, but the software is quite robust and has been used millions of times on millions of vehicles. It's fairly safe and highly-automated. For VWs, for example, you just select the appropriate module and it will present you with some of the options you can change with simple checkboxes. In most cases, the worst thing that can happen is that you just enable a feature that's unsupported and nothing happens.