Data Logging, A Basic How To

I've just started messing around with the data logging options we have available to us.. and I’ve been extremely surprised at how easy it actually is.

 

 

My goal here is combine all the information I've gathered so far and collect it into one place so members here can have a reference for their logging needs.

 

 

Hopefully, this will encourage more people to begin data logging and contribute to the information we have already collected.

 

 

Please feel free to add your own contributions and corrections.

 

This walkthrough is designed to be used with the TARI RACING SOFTWARE, available FREE at http://www.tari.co.za/cgi-bin/yabb2/YaBB.pl?num=1125302367

 

 

WHAT YOU WILL NEED

 

1)A laptop with a serial port, or

2)A USB to serial adapter (or PCMCIA to serial adapter)

3)OBD to Serial cable. I have been using the cable supplied with my Cobb AccessPort. Other cables are available for sale at http://www.tactrix.com/

 

 

 

 

Getting Started

 

 

1. Calvin at TARI has put together an install package – (http://www.tari.co.za/cgi-bin/yabb2/YaBB.pl?num=1125302367)

***Direct Download SetupDL1.exe***

***Mirror link ***

 

 

2. Run the setup.exe file you just downloaded, it should talk you through the setup process and is pretty straight forward.

 

 

3. Make sure you’re laptop is charged up, Grab your Serial adapter and OBD cable and head out to your car

 

 

4. Plug the ODB end of the cable up to your car. The Connection is made in the drivers side foot well, in the area above the dead pedal and below the fuse box. You can’t miss it.

 

 

5. Connect up to your computer and start the TARI DL1 application

 

 

USING THE TARI DL1 Application

 

 

1. Once the cables are connected and the application is running – you may notice that several tabs are grayed out and unavailable. This will be the case until a connection has been established with the car.

 

 

2. To establish connection, Turn your ignition to the ON or ACC position. You do not need to start the engine. You should now see “Connected” in the bottom of the application and you will have access to the “LIVE” and “Alarm” tabs.

 

 

3. Go ahead and open the LIVE tab, here you will see all of the variables that you can log. The upper window lists the continuously changing analog variables, such as engine speed and throttle position. The lower window lists your digital parameters. Those are ones that only have 2 states, on or off.

 

 

4. As you select which parameters you want to monitor you may notice the logging interval (listed in milliseconds at the bottom of the window) increase. The lower the interval, the faster the parameters are updated. The more parameters you select, the slower it will go. I try to limit myself to 10 parameters.

 

(note - if you select to many paremeters - IT WILL NOT WORK)

 

 

FOR ECU EXPLORER

A more detailed write up is coming for using ECU Explorer - however the tari forums are a good source of information in the mean time. The thing to watch out for when using this software is to remember to select which com port/ device to use in the lower left hand box - and then right click on the main window to bring up your options for logging.

 

 

LOGGING DATA

 

 

 

If you’ve gotten this far, then you’re doing good – all that is left is to actually log some data. The way the application is designed, it uses the defogger switch on you car as the start/stop button for logging.

 

 

1. In the TARI DL1 application, open the “CAPTURE” tab at the top of your screen and verify that “trigger logging on defog switch” is checked off. If it isn’t, check that now.

 

 

2. In the DIGITAL DATA ITEMS window check the box to monitor the DEFOGGER SWITCH. This is important, if you aren’t monitoring the defog switch, the software won’t know when to start or stop logging.

 

 

3. Go ahead and press the rear windshield defog button on your center console. In the software you may notice the text at the bottom of the application will change to reflect the fact that it is logging data.

 

 

4. After it has run for a while, press the defog switch again to stop logging and open up the log file to verify that it worked. The log file should be located at :

C:\program files\TARI Racing Software\My Product name\logfile.CSV

 

 

5. The log is saved as .CSV spreadsheet that will open in Microsoft Excel.

 

 

 

 

So now you’re ready to log… That’s all there is too it.

 

Of course, logging data is only good if you can make sense of the information you’ve got. So here is my attempt to explain the different data fields available and what they are.

 

 

 

I’m hoping that other members here will help me fill in the gaps on the things I don’t know.

 

 

 

 

 

 

 

First, let me show you what you can monitor:

 

 

 

 

ANALOG DATA VALUE

 

Engine Speed............................ RPM

Manifold Absolute Pressure ........PSI

Air/Fuel Learning #1 ...................%

Air/Fuel Correction #1 ................%

Coolant Temperature ..................Deg. F

Rear O2 Sensor .........................Volts

Throttle Opening Angle................. %

Mass Air Flow ............................g/s

Air Intake Temperature Deg. ........F

Ignition Timing Deg. ....................BTDC

Vehicle Speed ...........................KPH/MPH

Atmospheric Pressure ................PSI

Knock Correction Deg. .............BTDC

Fuel Injector #1 Pulse Width ......%

Air Flow Sensor Voltage ...........Volts

Battery Voltage ........................Volts

Fuel Temperature..................... Deg. F

Accelerator Opening Angle .......%

Fuel Tank Pressure ...................PSI

Manifold Relative Pressure .........PSI

Tumble Valve Position Sensor....Volts

CPC Valve Duty Ratio .................%

Primary Wastegate Duty Cycle ......%

Fuel Level ....................................Volts

Fuel Pump Duty ...............................%

Tumble Valve Position Sensor (L)...Volts

Air/Fuel Sensor #1 Current............. ma

Intake OCV Current Left ................ma

Intake OCV Current Right.............. ma

Intake OCV Duty Left ....................%

Intake OCV Duty Right ...................%

Intake WT Advance Angle Left .......Deg.

Intake WT Advance Angle Right .......Deg.

Air/Fuel Correction #3 ........................%

Air/Fuel Sensor #1 .............................AFR

Air/Fuel Sensor #1 Resistance ............Ohms

Throttle Motor Voltage ......................Volts

Main Accelerator Sensor ...................Volts

Sub Accelerator Sensor .....................Volts

Main Throttle Sensor ........................Volts

Sub Throttle Sensor ..........................Volts

Memorized Cruise Speed................... MHP

 

 

 

 

 

DIGITAL DATA VALUE

 

Test Mode Connector On/Off

AT Vehicle ID On/Off

Air-Con Switch On/Off

Power Steering Switch On/Off

Ignition Switch On/Off

Idle Switch On/Off

Neutral Position Switch On/Off

Knock Signal #1 On/Off

Rear O2 Rich Signal On/Off

Starter Switch On/Off

Interior Light Switch On/Off

Blower Switch On/Off

Defogger Switch On/Off

Cam Position Sensor On/Off

Crank Position Sensor On/Off

Blowby Leak Connector On/Off

Radiator Fan Relay #2 On/Off

Radiator Fan Relay #1 On/Off

Air-Con Compressor Signal On/Off

Vent Solenoid Valve On/Off

TGV Drive On/Off

TGV Output On/Off

PCV Solenoid Valve On/Off

Tank Sensor Control Valve On/Off

Torque Control Signal #2 On/Off

Accelerator Switch On/Off

Brake Switch On/Off

Resume Accelerate Switch On/Off

Set Coast Switch On/Off

Stop Light Switch On/Off

Clutch Switch On/Off

Roughness Monitor Cylinder #4

Roughness Monitor Cylinder #3

Roughness Monitor Cylinder #2

Roughness Monitor Cylinder #1

Some parameters are self explanatory, others are not. I won’t pretend to know what they all mean but I can explain some. Here is what I’ve gathered so far (much of this was taken from the website listed above)

 

 

 

Boost related:

 

 

 

Primary Wastegate duty cycle – the higher the duty cycle, the higher the boost. If you see 0%, you will see either no, or negative boost.

(*Hopefully somebody can explain this better than me*)

 

 

 

Atmospheric Pressure – The outside air pressure. Around 14.5 PSI at sea level. This sensor reads both atmosphere and manifold pressure so it may not update continuously.

 

 

 

Manifold Absolute Pressure – Pressure in the manifold relative to a vacuum. You would subtract 14.5psi to get the relative pressure. (1 Bar = 14.5psi)

 

Manifold Relative Pressure – Common measurement for ‘boost’. You will see negative numbers here during idle or limited load on the engine, and peaks around 12 or 13psi under full boost (stock) and 15psi if your AP stage 1.

 

 

 

 

 

Intake air temperature– This is the temperature of the air at the intake filter, basically the temperature inside the engine bay. It will read a bit warmer than outside temperature, especially at stoplights or while at idle. This is not the charge temperature, after the air goes through the turbo it will heat up substantially.

 

 

 

 

 

 

 

Fuel / Engine related:

 

 

 

Injector Milliseconds – measured in milliseconds (Duty cycle is an option under the ‘capture tab’). This measures the number of milliseconds that each injector is open for each cylinder cycle. If you see your duty cycle maxing out then it is a good sign that you need larger injectors.

 

 

 

Air Fuel Sensor #1 – AFR, Air Fuel Ratio : it's the ratio between the mass of air and the mass of fuel in the air-fuel mixture. AFR = M(Air)/M(Fuel).

 

(Lambda (greek letter) : it's defined by the ratio between the actual measured AFR and the stoich AFR. Therefore, if an AFR of 14.7 is measured in the exhaust gas, Lambda = 1. Lambda is often used in Europe.)

 

-LEAN (represented as a Higher AFR) gives better combustion, and better gas mileage. To lean is dangerous, can cause knock, higher temperatures, and higher NOx emmissions, among other problems)

 

-RICH (represented by a lower AFR) allows for more torque, thus more power. However this is at the cost of fuel economy. Also reduces NOx emmissions. However unburnt fuel passes through the exhaust and can cause fouled spark plugs, diry tailpipe, and probably catalytic converter problems.

 

 

 

A/F correction and Learning - #1 is the front sensor, #3 is the rear sensor. These are used to calculate the AFR short term correction values to maintain the proper AFR.

 

 

 

Rear O2 Sensor – Measures O2 levels in the exhaust, it is used to calculate proper AFR.

 

 

 

Exhaust Gas Temperature - Reports the temperature at the exhaust of the car. It only reads as low 370 degrees so don’t be surprised when you see this with your car turned off. If the temperature is to low then your Catalytic converters won’t work properly, while if it gets too high you risk CAT damage. I think anything in the area of 1500 degrees is normal for our cars.

 

 

 

Ignition Timing - The timing that your engine is currently running, including any knock correction

 

 

 

Knock Correction – I’m pretty sure it only reads -8 to 12 or higher. The amount of timing added or subtracted from the ignition timing. Negative values are bad, and indicated pulled timing due to the presence of knock. Positive Values are good and indicate an increase in timing. The more timing you can get without knock means the more power you can get. Knock is BAD, if you see consistent negative numbers than you’ve got something wrong. The periodic dip into negative numbers isn’t bad. Causes of knock can include lean AFR, high temp, bad gas, low octane gas, and many other causes.

 

Intake OCV duty/current - Intake OCV is the Oil Control Valve that changes the cam timing

 

Tumbler Valve position - Tumbler Valve position is the position of the Tumble valves

 

Intake VVT advance angle Left/Right – Variable Valve Timing. Reports the amount of intake cam advance applied. One for the left side of the engine, and one for the right. Higher angles allow the engine to ‘breathe easier” under load. If you always notice large differences between the left and right, it could indicate a problem.

 

 

 

Oil Control Valve duty Left/Right – This, along with the valve duty current sensors help control the VVT angle.

 

 

 

 

 

 

 

BASIC STUFF

 

 

 

Engine speed – as measured in RPM

 

Battery Voltage – should be in the area of 14volts with the car turned on

 

Coolant Temp. - should be 85-95 for a ‘warmed up’ engine. Rule of thumb is let the engine get to 80 before really pushing it.

 

Vehicle Speed - change between KPH and MPH in the “capture” tab.

 

 

 

Mass Air Flow - the rate of flow of air into the engine

 

Throttle Angle – how open the throttle is – such as how hard you pressing on the gas pedal

 

Accelerator Pedal Sensor – relative to the position of the gas pedal. The fly-by-wire system takes this data and controls the throttle angle.

 

 

 

 

 

Digital Data Items

 

 

 

These are usually switches, and only have a 1 or 0 value, indicating on or off.

 

 

 

You may want to keep an eye on the knock sensor, which will turn on if knock is detected.

THE KC values read higher than +8, I have logged as high as +10, and I have heard it can go to 12?

 

Anyway, very nice writeup! It will certainly help alot of us out in getting acclimated with logging.

Nicely written, thanks, hopefully get lots off people logging once they know how easy it is.

 

With the PWDC, I often see 50% operation at very low rpm's, as if the ECU is getting the gas to bypass the turbo until the rpms climb up to over 3,000. Maybe this is to help stop and go driving when you dont want the boost coming on at all ?

thanks for the input guys...

 

 

I too hope this gets more people logging so we can start collecting some solid data from various mods.

We might even get a forum just for logs.......................

Intake OCV is the Oil Control Valve that changes the cam timing

 

Tumbler Valve position is the position of the Tumble valves

Nice write up...

 

Might want to change the first post to reflect that fact that some laptops do still come with a serial port.

Doesn't a higher AFR mean leaner? AFR = air/fuel, so higher means more air/less fuel.

 

???

Doesn't a higher AFR mean leaner? AFR = air/fuel, so higher means more air/less fuel.

 

???

 

Yes. It's the ratio of air to fuel, for example 12.7:1 means 12.7 g of air for every 1 g of fuel.

 

The higher the number gets the leaner the mixture is.

Hey phil..do you know what point TPS % the fueling switches over to open loop?

Air Fuel Sensor #1 – The default measurement is Lambda, however under the “capture” tab you can change that to read AFR instead. This is the air/fuel ratio and is measured at the engine exhaust before the first catalytic converter.Lower AFR’s reflect a ‘lean’ condition which means your engine is getting less fuel and more air. This can cause ‘knock’, pulled timing, and higher temperatures, and should be avoided.

Then this text needs editing.

 

I'm considering picking up a cable so I can log some stutters and use that when I go back to the dealer and say the ECU reflash definitely didn't fix the problem.

One thing also worth mentioning is that the more parameters you log at the same time, the longer the sampling period is between each point.

 

Sorry Jarrod, I'm a n00b at this logging, although I'm learning pretty quick

sorry I'll correct the AFR definition to make it more accurate.. All this time I've been reading it backwards, not quiet sure how it got in my head...

 

oh well, thanks for clearing it up. Please keep the corrections and additions coming.

I'm king of new at this logging to..i'm using the logger in the utec

awesome post? can we sticky it?

I've got to find a better way to read data out of the OBD port than the AP cable.

 

I wanted to do some logs while I was at the track this past weekend, but the cable wouldn't stay plugged in around the turns... It cant handle the G's.

 

 

anyone have any ideas. I'm thinking of a more permanent solution that will run a serial cable through the center console down under the passenger seat to what will eventually be the location of a carputer.

Very well written, congrats and thanks for the info!!!!

 

Good luck with your new findings and work to be done,

 

Cheers,

 

Flavio Zanetti

Boston, MA

Has anyone taken any logs using the new Ecu Explorer ? I'm having trouble getting it to recognise my serial port. Looks a big improvement, if only I could use it !

Has anyone taken any logs using the new Ecu Explorer ? I'm having trouble getting it to recognise my serial port. Looks a big improvement, if only I could use it !

 

I haven't tried it yet.. I need to download it and check it out..... I'm really waiting for the guy who made it to release the source code.. I've got a couple of cool things I would like to do with it - but dont feel like desinging it from the ground up.

rallispec -

 

First, please keep in mind, brother, that I have NOT attempted this on my LGT....

 

With that disclaimer in-mind.

 

In my many trips below that part of the dash (hardwiring my X50/ZR3 combo, which has its own control box, plus the DRL/fog mods, plus wiring-in my NEXUS's control module), I've had to remove the OBD-II port several times in order to completely remove the toe-guard/cabin noise-isolation trim piece under the dash/column.

 

I would think that as you're currently having G-force related issues, and would furthermore like to completely "bury" the attachment point between the OBD-II port and the logging-tool cable, why don't you simply remove the four screws securing the OBD-II port to the trim piece?

 

This way, you can now tuck the OBD-II port inside/underneath the dash, tape/clip together its connection with your logger-cable so that it does not come loose, and use under-dash space, proceeding towards the center of the vehicle and thus "under" the middle console, for your planned routing of the car-puter wiring.

 

Of course, you'd have to go back under the dash to "unclip" the logger connection and to replace the OBD-II port's securing screws when you take the car in for an emissions-check or dealer-servicing....but overall, I'd say this should be a viable trade-off between convenience and practicality.

rallispec -

 

First, please keep in mind, brother, that I have NOT attempted this on my LGT....

 

With that disclaimer in-mind.

 

In my many trips below that part of the dash (hardwiring my X50/ZR3 combo, which has its own control box, plus the DRL/fog mods, plus wiring-in my NEXUS's control module, I've had to remove the OBD-II port several times in order to completely remove the toe-guard/cabin noise-isolation trim piece under the dash/column.

 

I would think that as you're currently having G-force related issues, and would furthermore like to completely "bury" the attachment point between the OBD-II port and the logging-tool cable, why don't you simply remove the four screws securing the OBD-II port to the trim piece?

 

This way, you can now tuck the OBD-II port inside/underneath the dash, tape/clip together its connection with your logger-cable so that it does not come loose, and use under-dash space, proceeding towards the center of the vehicle and thus "under" the middle console, for your planned routing of the car-puter wiring.

 

Thats the long version of saying "move it"

Thats the long version of saying "move it"

 

heh... pretty cool idea though, i hadnt really thought of doing it that way.

 

 

THanks for the input TSI+WRX... i'll give it some thought and poke around under the dash and see if that looks like a good solution.

NP, brotha.

 

PhilT - I often lose my wordly elegance for wordy diarrhea!