Ok so I am a computer software geek. I have been creating mobile (12V)computer applications in a completely different market. But the idea of adding software to my 914 is really inspiring me. I would love to be able to get OBDII type info from 914 analog sensors installed on stock instrumentation, FI systems and cool third party user components (analog or digital).

So who is doing this? Or is my wife correct... Who cares!

Regards,

James

Dunno who is doing it, but it sure sounds neat!!

--DD

Hey James,

It's funny, just after you called I remembered I just received an email from this guy.....

This guy, Sergey Yurish, writes over @ sensorportal.com. Their brain trust has helped me on a project of my own.


Here is the article describing the analog to digital converter which uses low voltage.

http://www.sensorsportal.com/HTML/DIGEST/P_243.htm

I'd love to hear more about the details of your project.
Sounds exciting, especially if it can be used on a 914 for performance gains....
Whatcha' building?????

I agree it sounds cool. i would be interested..

I would offer an opinion and advice... if I knew what you were talking about.

For all that effort just go to SDS or Megasquirt. You can log everything under the sky!

Easy is well, just too easy! I want to do it the hard way. I just like banging my head against a wall . Why else would I have purchased my third teener (and of course I had to pick an l-jet!).

I think it would be totally cool to sample and record the inputs and outputs of the ecu in “real-time”. Obviously once you had normal operating parameters identifying in “real-time” component or system level deviations would be a piece of cake. Also, adding new sensors would be totally exciting! For example adding an O2 sensor would enable you to really tune the exhaust gas numbers (closed system)… Tracking ecu data history for component trends would be really interesting in spotting potential component failures. Etc…

I realize that OBDII and current technology provides what I am describing and more. I just want a modern approach to solving the non-digital 914 problem (and knowing when I have solved the problem) of “why my engine is running rich or lean or idles rough”. I want to plug a computer interface into the harness have the computer tell me what component is out of spec (e.g. fault code!) and of course a lot of other cool stuff.

However once you can control the ecu responses based upon ecu inputs. We are know at a another level. Once there, creating driving modes street, track and smog level based upon ecu inputs is totally doable – we could all be sharing digital engine performance profiles.

So has anyone done or is working on anything remotely similar to what I am describing? Is my wife correct… No one cares.

Rodger, thanks for the info I found a lot of new information.

Regards,

James

How about digital to analog. I just purchased my first turntable... and cannot wait to spin some records.

Cool idea, need an a/d converter not sure how you would control the programming on a stock 914 as it is mostly hard coded in the circuitry (am I wrong here?)

If you mean chaning the ecu output based upon FI component inputs then yes. If you mean can I create an album. Yes but you will need this device

The ECU is old....not a single IC chip, no code, nada.

If you got a megasquirt you could write your own program, you do build it yourself.

I have an SDS and a wideband, I can change/watch/log anything enginewise if I want.
But I don't even bother with it, once set it comes off and sit's in the glovebox.

I bought this for my new motor when I get it installed. What I thought would be one month is now four.

http://www.innovatemotorsports.com/products/kits.php

It will allow input signals from a CDI box as well as other analog inputs to be recorded into a computer.

I agree. Consider this. Suppose you did build what you are talking about.
(which would be quite complicated by the way).
Now what would you do with sampled data?

The stock FI system is completely analog and for the most part hardwired.
If you want to change something, you have do things like swap out
resistors and capacitors.

I'd say if you really want to play with things, move to MegaSquirt. This
can do the things that it sounds like you want to do.

Here is the the link to the MegaSquirt web site if you haven't been there yet.

MegaSquirt

--- bill

my buddy and i use software to reprogram his ecu on the fly and monitor all kinds of stuff in real time. he uses openecu and a special cable that hooks his obdII port to his laptop

check out: http://openecu.org/index.php?title=Main_Page

not sure if it will help with any conversion stuff, but its interesting nonetheless

Do it! This would be cool, even though it is not necessary IMHO, I would be interested in seeing it done if you want to tinker

I think it would be cool also. Even if only Dwell, timing, battery voltage and the CHT were digitized.

This might be a dead thread, but I'm looking at a PICO ITX on board computer to integrate with the 95 993 3.6 I'm putting in my teener. I also plan on integrating all the other goodies like GPS navigation and entertainment radio in the on board computer. I figure with the limited dash space on a 914 that having a software driven interface would allow me to have any engine data I want at a touch of a... well touch screen.

You can buy a retractable touch screen system that would fit in the radio hole (if it's been cut out) for around $150 --> $500 depending on what you want.

You can put an Pico ITX computer together for around $300 or so.

My biggest hurdle will be comming up with the software to talk to the OBD-I Motronic unit. The 993 units use a non-standard code format as well. I'm currently investigating going to a 96+ OBD-II unit. I hear most 993 guys are trying to go the other way because the 95 OBD-I unit is chipable but the 96+ OBD-II units have the EEPROM's soldered directly into the boards.

Got to go open presents! bye bye

I have nothing to add... but nice use of the Search feature.

In order for the sensor data to be of value the characteristics of the sensors must be known. Is there any information that gives Bosch sensor ranges? The Bentley manuals only state that the resistance is inversely proportional to the temperature. Or do the sensors need to be calibrated using thermocouples, mechanical gauges, ...?

This is actually pretty easy using products meant for experimental aircraft...they do stuff like this all the time. Here's part of one system I've installed, the Enigma by MGL Avionics. Converts whatever you want to whatever you want. Here's a picture.

So what do you do for soft-gauges to run with this?

I'm trying to set mine up to copy the stock black and red VDO analog gauges.

Thanks

According to sources I've read on OBD diagnostics, the values are standardized between certain manufacturers on OBD-II systems and standardized between manufacturers for OBD-I systems. I hear there are a lot of variances when dealing with OBD-I.

There are free and pay for applications that you get get off the NET that already have these values mapped out. I've been eye-ing this one for a 95 993 system. It's intended for GM products, but he has made a version for an Audi Motronic system that I'm hoping will be very close to the Porsche Motronic.