Installing a Data Logger on a Gen II

[SmokinViperGTS]

I'm looking seriously at installing RLC Racing's Micro Pod Lite data logger on my '99 GTS, and have encountered a few difficulties. I'm wondering if anyone else out there has installed any data logger on a Gen II, and how they solved a couple of issues.

The Gen II's don't have an OBD-II port, and the onboard OBD-1 is too slow to use, so I have to find some other means of getting data. I've been told to look for a diagnostic port under the hood, and see if it has a clear tach channel. Anyone know the answer to that?

Also, where's the best place to pickup engine temp data - same port?

And, have you had any issues with mechanical sensors for throttle position and brake position?

The RLC has a feature for manual calibration of gear position, so a sensor is not needed for that. It also has on-board GPS and accelerometers, so those are built-in.

Is there anything else that I really should be instrumenting?

My goals for this project are two: a) give me some data tools to help evaluate my driving on track days (for fun - I'm a hobbyist), and b) make some really, really cool videos by overlaying virtual instruments from Chase Cam's Dashware, driven by real data, on top of the HD video I'm capturing.

Thanks,
Steve

 

[Steve-Indy]

"...The Gen II's don't have an OBD-II port,..."

WRONG !!!

By LAW they must...and do.

Referred to as a Data Link Connector...it's under the dash on the driver's side...to the left of center.

 

[plumcrazy]

what steve said

 

[SmokinViperGTS]

Hmmmm.... what I've been told is that Gen I's and II's (i.e. my '99) have the "original OBD" port, which pre-dates OBD-II, and is commonly called OBD-1. RLC told me the data rate on the port is about 1/10th of that on a more modern OBD-II port.

Interestingly, I saw some evidence of this data rate issue on the dyno, when they had a heck of a time getting the data through it on the Gen I's and II's at DynoDay this spring.

Gen III's and later have the higher-speed OBD-II version, so there's no problem there.

That's what I'm told - is it wrong?

 

[Steve-Indy]

Well, I'm really in no position to say what's right/wrong...but, you are correct in that the PCI bus (J1850) used on the Gen II and Gen III is slow...but that's all you have...period.

Gen IV's use CAN bus for the PCM functions and ORS, though it still uses PCI bus for the other functions. CAN bus is FAST !!!

 

[SmokinViperGTS]

Thanks Steve - you seem to know a lot about it. I'm gonna go way out on a limb here, and assume that upgrading to a CAN bus is not a very practical idea?

Which leaves me with: How do I get a feed for the tach and engine temp data? Clearly the car has these gauges, so there must be a feed somewhere. Is this "diagnostic port" my answer?

I can't really be the first guy to want to put a data logger in an older Viper. Someone out there must have done this before?

Steve

 

[Steve-Indy]

CAN conversion not practical.

Try the DLC (OBD II) port...think you'ii be pleasant ly surprised...for short term, non-invasive snooping.

I only use the port for my own diagnostic amusement...but many have done great things tapping into the PCM. Hopefully, some will chime in here.

 

[Tom F&L GoR]

OBD-II should have been introduced in 1996. Original Gen 1 cars (as all cars were) are OBD-I.

Given all the things you want or can measure, you should get a service manual. It will then be easy to locate and pick sensor signal wires.

 

[ViperGeorge]

While I am not familiar with the RLC device you mention, I have used an Autotap data logger plugged into the OBD II port on my Gen 3. Autotap can log virtually any data available on OBD II in table, graph, or gauge format. However, I was told by Autotap that the PCM in a Gen 3 and earlier cars with the PCI bus is too slow to report more than about 4 parameters reliably. I guess that is because the data logger is actually sending queries to the PCM for the data. Not sure if that is entirely how it works.

Many of the parameters on the OBD II list change so rapidly that the data would be useless unless it is captured by the logger quickly. You could end up trying to analyze one parameter against another when they were in fact captured at different times (even small time differences can show changes in timing, fuel map, or other things). Well at least that's what I've been told by Autotap.

 

[Canyon707]

Look at the Gtech. I think the link is gtech.com

 

[luc]

I have an AutoXray with live data stream and I have no problem getting water temp, rpm, intake temp, etc, etc through the OBD2 port.

Luc 00GTS

Thanks Steve - you seem to know a lot about it. I'm gonna go way out on a limb here, and assume that upgrading to a CAN bus is not a very practical idea?

Which leaves me with: How do I get a feed for the tach and engine temp data? Clearly the car has these gauges, so there must be a feed somewhere. Is this "diagnostic port" my answer?

I can't really be the first guy to want to put a data logger in an older Viper. Someone out there must have done this before?

Steve

 

[AviP]

I have an Equus OBDII live scan tool and from what I remember, the engine tach and temp data are displayed. I'll check it later if I can find the darn tool.

 

[Russ M]

Out of curiosity why not just install an AEM unit which can datalog anything you like, not to mention do all the other stuff it can do?

 

[ViperGeorge]

Out of curiosity why not just install an AEM unit which can datalog anything you like, not to mention do all the other stuff it can do?

What's an AEM unit?

 

[SmokinViperGTS]

OBD-II should have been introduced in 1996. Original Gen 1 cars (as all cars were) are OBD-I.

Tom - Thanks! Steve-Indy - You were right - it was wrong.

I called RLC again today, and talked to an engineer for the product. That gave me a bit more clarity. They agreed with you that I should have an OBD-II port, but mentioned that older OBD-II ports ran at slower sample rates than newer ones, and different brands/models put different information on the ports. So, they advised me to try to determine if my '99 OBD-II:

a) ...has a sample rate closer to 20 than to 10. Around 10, the tach stream is readable but NOT useable - it skips too much. Around 20, it's useable, and I shouldn't have a problem with it.
b) ...has engine temp data available
c) ...has throttle position data available
d) ...has brake position data available

With answers to these questions, I can go back and determine which wiring harnesses and sensors I will need.

Out of curiosity why not just install an AEM unit which can datalog anything you like, not to mention do all the other stuff it can do?

I have an AutoXray with live data stream and I have no problem getting water temp, rpm, intake temp, etc, etc through the OBD2 port. Luc 00GTS

Look at the Gtech. I think the link is gtech.com

Thanks - I'm not familiar with those products, but I'll go look at them. The reason that I chose to start with RLC's product is because of their tight integration with Chase Cam. They have done collaborative engineering together, so they actually provide a free software conversion utility that will convert their data streams to the Chase Cam format, which I can them embed into the video stream, so that the resulting video actually uses real data to drive computer generated instruments overlaid on the video. It's kinda like what SRT-Experience provides, but waaay coooler. And if I was using Chase Cam's video recorder (which I'm not, because they don't record High Definition, which I'm using), then all the integration happens real-time, as you're driving.

Steve

 

[Tom F&L GoR]

I'm not going to be much help here, but there are several diagnostics that all OBD-II systems provide and are available with the generic code reader. I would guess the tach is one of them.

Each OEM also has their own proprietary data stream which you would only see with their specific reader or by purchasing added software. I'll guess that things like throttle position and both temperature sensor signals fall in this category. I don't know if RLC includes this extra Chrysler software.

You might get all the answers in one place by visiting your local Dodge dealer and paying for a diagnostic look-see. 30 minutes looking over the tech's shoulder while they scroll through every data field would tell you a lot. The training I suspect they get would also let you know sample rates.

 

[Steve-Indy]

Steve...give me a call.

 

[Jack B]

Take a look at the Innovate DL32. It is an accessory item for their wideband O2 sensors. It can take the input from 32 analog points. I pick up rpm, (2) O2 sensors, fuel pressure, Map, Throttle, acceleration (G's), IAT or ECT. You can pick most of these from the wiring harness or at the sensor. If you already have purchased the other unit, you should be alble to do the same if it allows the input of 0-5V signals.

The oem OBD two port is OK for some items, but, there is too much lag for some real time logging with certain PIDs at wot.

 

[Jack B]

Take a look at the Innovate DL32. It is an accessory item for their wideband O2 sensors. It can take the input from 32 analog points. I pick up rpm, (2) O2 sensors, fuel pressure, Map, Throttle, acceleration (G's), IAT or ECT. You can pick most of these from the wiring harness or at the sensor. If you already have purchased the other unit, you should be alble to do the same.

The oem OBD II port is OK for some items, but, there is too much lag for some real time logging with certain PIDs at wot.

 

[SmokinViperGTS]

Jack,

I'll look at the DL32. The standard wiring harnes for the RLC has 4 analog ins, 2 digital ins, CAN-bus in, and 2 digital outs. They have numerous expansion harnesses that support up to 32 analog and 8 digital ins, with 8 digital outs. Sounds pretty similar.

My needs are more modest at this time, and I'm *assuming* that hooking up separate digital/analog sensors for tach, engine temp, throttle, and brakes is going to be expen$ive, although I could be way off base on that. Especially given that the OBD-II wiring harness is $500 by itself.

Where did you get the information on how/where to tap into the wiring harness to get all of this data - the standard shop manual??? Maybe I should seriously consider switching gears here, and go with discrete sensors like you suggest. While I'm not much of a mechanic, I'm pretty darned good with wiring....

Steve

 

[SmokinViperGTS]

Steve...give me a call.

Sure - where? You've got your PM's turned off. Mine are on, if you'd like to drop me a number.

 

[Steve-Indy]

Nice to speak with you!!

 

[Steve-Indy]

Another product...some of the same questions regarding sampling rate/delay:

OBD-II performance computer monitoring... - MBWorld.org Forums

 

[SmokinViperGTS]

Thanks Steve - it sounds like the slow sampling rate of older OBD-II ports is a pretty common problem - especially for tach input.

Hopefully, Jack will come back with some info on how/where he hooked up separate digital/analog sensors for tach, engine temp, throttle, and brakes. Otherwise, it looks like I'll be trolling for a shop manual.

Thanks,
Steve

 

[Jack B]

Jack,

I'll look at the DL32. The standard wiring harnes for the RLC has 4 analog ins, 2 digital ins, CAN-bus in, and 2 digital outs. They have numerous expansion harnesses that support up to 32 analog and 8 digital ins, with 8 digital outs. Sounds pretty similar.

My needs are more modest at this time, and I'm *assuming* that hooking up separate digital/analog sensors for tach, engine temp, throttle, and brakes is going to be expen$ive, although I could be way off base on that. Especially given that the OBD-II wiring harness is $500 by itself.

Where did you get the information on how/where to tap into the wiring harness to get all of this data - the standard shop manual??? Maybe I should seriously consider switching gears here, and go with discrete sensors like you suggest. While I'm not much of a mechanic, I'm pretty darned good with wiring....

Steve

It is simple, pick up the analog's at the sensor or at one of the three connectors below the PCM. If you already have the logger, there is very little cost involved. The only question would be the rpm, that typically is picked up at one of the coil pack drivers. That is not a 0-5, but, I would assume your logger can interpret that input.

Yes - the shop manual gives you all the wire codes. One note of caution, there are three connectors, the one on the left is C3, then C2 and C1 on the right. To me that breaks protocol.

 

[SmokinViperGTS]

It is simple, pick up the analog's at the sensor...

I've got a shop manual on the way - should be here in a week. Do you happen to know if there are sensors already installed for throttle position and brake position? Or where the engine coolant temp sensor is?

The only question would be the rpm, that typically is picked up at one of the coil pack drivers. That is not a 0-5, but, I would assume your logger can interpret that input.

I haven't purchased any logger yet - I want to understand how to get to the goal before I do, as it will affect my choices for the logger, wiring harness, sensors, etc. Basically, I just want to have a solid plan before I start spending money, and try to make sure that I'm buying the right parts 'n pieces to begin with.

I still have to do some more research on the units mentioned already on this thread, but I've checked the RLC unit, and they offer two different digital sensors for tach, coil-over(0-12v), and plug wire. They also offer a whole range of analog sensors, in either 0-5v or 0-12v. Some sensors are cheap - $60, but others are $250-300+, and the wiring harnesses run from $400-1200 each. This is plus the cost of the logger itself, so you can see why I'm trying to get it figured out first.

If I can pull the data off of the PCM (or existing sensors), I could save $750 in sensor cost, $500 for an un-necessary OBD-II wiring harness, and a lot of time!

Thanks again for your help!

Steve