engine data acquisition

piggdekk · 05-25-2013, 12:49 AM

Hello guys,
in my day time job I deal with control system of chemical plants so I'm basically addicted to data analysis and control. Problem is that when I play with my 911 (and with my other toys) I miss not having enough information to tune them.
So here is my question for You: how would You build a system to log engine data to a PC?
I've got plenty of tools to post process the data, so what I'm after is really a multichannel data logger that would allow me to collect raw data into my laptop. The kind of sensors that I'd like to read would be analogical ones (I'm not a CAN bus kind of engineer

), so TPS, temperature, pressure, lambda and so on. I'm aware each one of them requires its own transfer functions and they work with different outputs, hence a system like the AIM one would probably save a lot of time. However, those systems seem to be quite limited in the numbers of channels, and then I do not know if the data can be exported to other SW's for post processing.
any experience?
many thanks
luca

Dr J · 04:33 AM

I've used several types of data acquisition systems for experiments in the past and had the same desire to collect data on the car, as you do. The problem with a generic data acq system is that you will want to monitor an o2 wideband sensor which requires a complicated input to activate it. With this in mind it would be worth looking at an innovate system.

I have the LM2 which reads the wideband o2, tach, and 4 analog inputs of 0-5V. So I also read timing advance and manifold pressure. In the future I wanted to add accelerometer data or devise a system to determine what gear I'm in. With some work I could develop something to get speed info but as you can see, I'm running out of inputs! Innovate uses a serial daisy chain system, so with some effort it might be possible to read these and have the lm2 log them as well.

Innovate also has other systems that log more data and even built-in accelerometers and add ons to track more channels.

Another useful capability is the ability to log your data and not need a computer on board. The innovate does this well with an SD card.

After collecting the data you want to analyze it and the innovate software is pretty good. If you have powerful data analysis software like matlab it would be good to have the data in some exportable text format. The innovate system lets you create a matrix table of any 3 values which I have exported into excel. I haven't tried to do much post processing with other software because I haven't really needed to do so.

piggdekk · 05-25-2013, 05:26 AM

Thanks Dr. J for the infos. Yes I've checked out Innovate, AIM and others, but they all seem to have very few channels available for the price they cost. I believe i've seen a wideband lanmda analyzer that conversts the signal into a 0-5 volt for display, so perhaps that output could be used for logging purpose.
Looks like there are quite a lot Arduino's project in the web for data logging, I just wonder how complicate would that be. Do You guys have any experience with it? A collegue or mine plays a lot with Arduinos, so I'll ask him on monday how difficult is to build a device for data logging... In the meantime please keep suggestions coming

luca

piggdekk · 05-25-2013, 05:36 AM

This system looks quite nice for example:
AQ-1 Data Logger
but I really don't care of logging data on a SD card, if I could just get raw data straight to my PC I would be more than happy.
I apologize for my previous post, I meant, AEM, not AIM...

tirwin · tirwin's Garage

I was just doing some research on wideband O2 sensors. Came across these guys that have a logging solution. I know nothing about them other than what's on their website:

Zeitronix : Wideband Engine Datalogging Systems and Accessories

sjf911 · sjf911's Garage

Unfortunately, to collect data from the engine, you have to have the requisite sensors and the implied wiring harness associated with them. EFI cars have this, my MS3 allows me to log huge numbers of engine parameters, both direct and calculated, either serially from the ECU to my laptop or via SD card (higher resolution).

piggdekk · 06:33 AM

So Steve,
You are suggesting that one could use a MS3 just for datalogging? In this casehow many channels would be available? I believe it supports 8 channels, qhich makes it pretty much similar to the AEM one, but 3 times the cost.
What I had in mind was for example the possibility to log vacuum in each throttle body, EGT for each cylinder, couple of lambdas, TPS, and so on. As you see You quickly reach 20 channels or so.
luca

sjf911 · sjf911's Garage

I have an add on logger box (IOx, I/O Extender Board v1.0 for M2/Extra) that adds 8 ADC channels as well as 8 separate EGT channels, a 3-axis accelerometer, and a GPS for logging. This allows CAN pass through logging of my accessory sensors and accelerometer with my laptop (GPS not supported yet). The MS3 and MS3X combination has a total of 6 ADC channels for extra sensors outside of the dedicated sensors for normal EFI function (manifold pressure (MAP), crank/cam trigger (VR or Hall effect), intake air temperature (MAT), coolant temperature (CLT), and throttle position sensor (TPS)).
I don't think you would want to use the MS3 purely for logging purposes but that adding all of those sensors, you are 90% of the way to EFI.

Porsche84 · Porsche84's Garage

I have an AIM Pista in my car and I log all of the engine sensors and I added the LCU-One to log Lambda and EGT. The Pista dash is equipped to monitor 8 channels, but it is easy to add expansion units to add more thermocouples or sensors. I'm an AIM dealer and I specialize in Porsche so if you want to e-mail me at jandsaustin1 at verizon.net I'll be happy to help you find a solution

Lambda AiM LCU-One Lambda Controller

Expansion modules AiM Channel Expansion

If you are not looking for a dash, here is a more economical choice AiM EVO4

Tippy · 05-25-2013, 11:24 AM

With MegaSquirt, you can analyze dozens and dozens of functions. There's a dashboard under the datalogs that has many, many half-sweep gauges with all the parameters you want on top of the histogram of user-chosen functions.

allaircooled · allaircooled's Garage

Sometimes I tell myself I need to hang my blue collar shirt up, go back to school and get an education. That way I can understand half of what goes on around here on Pelican. You guys do some pretty cool *****.

dicklague · dicklague's Garage

the Daytona-Sensors AFR instrument measures AFR, RPM, and MAP. Stores 2 hours of data and comes with software. All for a little over. $400. The best kept secret in AFR with data storage.

OUr host sells them.

Dr J · 05-25-2013, 06:35 PM

Another option is something like this:

Data Acquisition Starter Kits

I bought an 8 channel one for miscellaneous use.

Funny you mentioned arduino. It has data logging capabilities and I bought one (now have two) and did a little reading on using it to collect data and daisy chain it to the lm2. That project is on hold.

I can verify that the arduino can use an sd card to store logged data. The mega has more inputs than the regular arduino. It can also do calculations and provide outputs so you could program it to activate a light or buzzer if it exceeds some parameter.

SCadaddle · 07:30 PM

Sho nuff? Fo real?

I'd suggest seat time, in your car, just like it is, to combat your "addiction".

A talking Trans Am would've been a LOT cheaper!

http://www.youtube.com/watch?v=dCY1pmBxg90

piggdekk · 05-26-2013, 03:56 AM

Quote:

Originally Posted by SCadaddle

Sho nuff? Fo real?

I'd suggest seat time, in your car, just like it is, to combat your "addiction".

A talking Trans Am would've been a LOT cheaper!

KNIGHT RIDER - KITT VS KARR - YouTube

piggdekk · 05-26-2013, 04:01 AM

Quote:

Originally Posted by Dr J

Funny you mentioned arduino. It has data logging capabilities and I bought one (now have two) and did a little reading on using it to collect data and daisy chain it to the lm2. That project is on hold.

Arduino is what I had in mind to start with. It really fits another of my addictions: the DIY one. However, as I'm always short of time I'm trying to figure out if I'm reinventing the wheel or not. The good thing with Arduino's is that they require little investment to start with and seems to be widely used.
BTW yes, there are Arduino's modules that allows to write on a SD card.
luca

Tippy · 05-26-2013, 06:06 AM

You could do MegaSquirt II for just data acquisition pretty cheap I believe, but you might as well go EFI and take advantage of it too.

jpnovak · 05-26-2013, 06:21 AM

What car is this going on? Depending on what you currently have for engine management (yes carbs are EM too) you may choose one route over another.

piggdekk · 05-26-2013, 07:05 AM

Jamie,
I was thinking of a tool for different applications. The car is a 71 911T, so good old carburators, but I'd like to have a tool I can use also for my motorbikes, some carb'd some EFI'd.
Megasquirt2 may be a good option to climb the learning curve without breaking the bank.
luca

jpnovak · 05-26-2013, 10:48 AM

It sounds like you just want the data. The MS systems will certainly provide you with the data. The challenge is that the MS2 will not data log on its own - you have to request the data either from a laptop (via tuning software) or a stand alone box. I built a stand-alone DAQ system for my track car since I could not have a laptop. I use a micro controller that interfaces with the MS2 ECU and contains a 3-axis accelerometer, 10Hz GPS and writes the data to an SD card for external analysis. There are still about 5 channels of open analog inputs. So, room to grow.

The challenge for you will be interfacing with the older engine. The AFR is easy with a stand alone WBO2. TPS will not readily adapt to the carbs. RPM can be pulled from points signal or the tach. additional temperature and pressure sensors can be added. Engine load would be measured by Manifold Pressure (MAP) but this would require drilling manifolds for hose connections.

Most of these variables above are part of the data package from any stand-alone EFI.

If it were me, I would make a list of all your must-have run-time variables and a list of would like to have data variables. Then figure out the best system that will cross as many off the list as possible.

Crunching numbers can be fun but frustrating. It is best if you can have your DAQ crunch as many as possible. Meaning, Let it calibrate voltage signals, etc. Much easier than running a Macro in Excel or using any other number crunching program.