AO

I use Harry's Lap Timer (HLT) when I'm on track with an external GPS recording location at about 10Hz. While pretty good, I've found that I would really like some additional data on my Coke Car, like RPM, Throttle, Temps, etc. So I was wondering if anyone has ever tried to use the k-line to interface with a OBD2 dongle?

HLT can capture data via WiFi/BT ODB2 dongles and integrate the data with other telemetry such as g-forces, position, speed, etc. However, because the 928 is not OBD2 compliant, we need to figure another way to make it compliant-ish.

I was thinking it would be cool if there was a way to hijack the k-line, put it into a OBD2 plug (along with +ive and -ive, etc) and then stick a OBD2 WiFi/BT dongle in there and be able to capture this data on my phone. It's very similar to how the STer captures data - just via WiFi/BT and to your phone. Just curious if anyone has ever tried doing it or if I'm completely wasting my time?

I was thinking these would be the parts needed (plus some wire).

OBD2 Pigtail

Thoughts?

Rob Edwards

My thought is that I'm not qualified to answer the question directly, but I would be interested in being able to do this with the Zombie (if I ever stop getting side-tracked by other projects...) My otehr thought is that I'll PM John Speake and Jim Corenman to get their input on this thread.

AO

I thought I would throw it out on the open forum, but yeah, that brain trust can probably answer this definitively. But I figured there would others that would be interested in a DIY solution.

jcorenman

You are correct, the 928 is not OBD2-compliant. The connection is one issue, and the parts you reference help solve that. But the larger (much larger) problem is that the K-Bus speaks a whole different language. The data you want is not streamed on the K-Bus at all, and if it were it would certainly not be in a format (language) that anything else would understand.

Which is why the Feds mandatated the OBD2 standard starting in 1996: There was no other way that the manufacturers would voluntarily agree on a single standard for diagnostic connections. The other wrinkle is that there have been different levels of OBD2 introduced over the years, and the track programs may not support all of them.

Sharktuner takes a different approach completely: It hijacks the K and L buses and loads special firmware into programmable memory modules (PEMs) which allow the Sharktuner software to interrogate real-time data. Again, not a format that anything else would understand.

So I see two ways to accomplish what you want: One is to find or build some modules which would covert specific basic parameters (RPM, coolant temp) from direct sensor readings and encode them to an OBD-compatible signal. Someone may have done this, I don't know.

The second would be to add a software module to Sharktuner to take the data that it has (e.g. anything that can be logged) and encode it into a OBD2 format. I think this is a do-able thing, the problem is that it would be a significant effort and with a customer base of only two the costs would be high.

Cheers,

John Speake

Jim's response is 100% correct, and I have nothing to add to that. Thanks Jim !

KenRudd

This issue is one of the major reasons I moved from HLT to an AIM system. While it is easier to configure AIM using a standard data bus ( OBDII or CAN), it is also straightforward using analog signals piped in for almost anything you want: RPM, Temp, Pressure, control position,etc.
Drawbacks:
1. Not Cheap
2. May require some creativity.

Best plan is to talk to one of the specialists who hang out in the "Data Acquisition and Analysis for Racing and DE" thread.

I recommend talking to Peter Krause "ProCoach" or "Matt Romanowski "

They won't know much about the 928 specifically since so few are tracked, relatively speaking, but if you treat it like a 944, they can get you started.

If there is interest, I can start a thread. I am in the middle of the process and have learned a lot.

AO

Thank Jim, John, and Ken for all your input. I knew someone would know.

Because I'm running this on a LH2.2 and not an LH2.3, this means I cannot use PEMs and therefore the whole STer thing is probably a non-starter for THIS car.

The AIM is an option but as Ken points out, it is quite expensive. I'll keep it in mind, should I find a good used AIM for sale at some point.

But now that I think about it, there is one other option, and it may have additional benefits to boot. If I were to convert from an LH/EZK based setup, and move to a Megasquirt system (or similar) that is OBD2 compliant, not only would I be able to capture these data more easily, but I could probably get some additional HP out of the system by going to sequential injection.

No matter, it sounds like it's an expensive solution.

Option 4: Buy a Cayman...

ammonman

Or a topless Cayman aka "Chickster"

steved0x

Auto Sport labs has an OBDII cable that receives can requests, translates it into various OBDII formats (for pre-can OBDII cars) and than returns the data back to the caller, who is unaware that it is not talking to a CAN-BUS car.

I emailed them a while back asking if they could do a "Porsche protocol" adapter that would use the K-Line to query the car, and they convert the responses back to CAN format, but I may not have explained it very well, and it didn't go very far.

I have a 2000 Boxster, and while the OBDII can give around 2-3 updates a second, using my Durametric I can get 10 pieces of data per second. I would love to get 5 RPM and 5 TPS updates per second to go with my data logging.

Even though it is not quite the same thing (instead of an OBDII port on the 928 it would have to be manually wired in, unless there is a different style port to access the k-line, like the older Durametric plug?), I think they are equipped to produce such an adapter, and it might be worth it to reach out to them about it?

https://www.autosportlabs.com/produc...egacy-adapter/

sfophietanar

Little bit different but related question. Would you like to suggest me any obd2 scanner tool please. I am looking for good quality obd2 scan tool to buy. I also need if any helpful link here.

dr bob

No 928 has any standard OBD built-in. There are some options for dedicated testing tools, but they only work on S4+ cars. Even so, the controllers progressed gradually in diagnostic capabilty. 1989+ cars have better capabilities. '90+ adds SRS/airbag systems along with new PSD electronic differential integrated with the ABS system.

PorKen

S3/S2 LH2.2 and EZF don't have diagnostic code or outputs so the whole idea is a non-starter. Have to use analog data acquisition, EG. Innovate.

Sequential doesn't make any more HP - it's better for low rpm. Converting to COP or CNP and a big gap will make a bunch more TQ, though.

GT4

KenRudd

Assuming you did not mean for your 928, but for other cars, look into one of the Blue-Tooth or wi-fi devices that connects to your phone. The available phone apps are powerful and are regularly updated