Data logger info needed

[hotrod]

The LM-1 is a toy that works great for a huge number of performance enthusiasts, and professional dyno operators, because it is the most cost effective system out there right now. There are a lot of street legal 9 and 10 second drag cars that were tuned using LM-1's, and without mine I never would have tackled the E-85 conversion I am working on.

Bottom line is get what you need at a price you can afford.

I would also suggest if you are juggling a tight budget you should at least check out the LM-1.

Larry

[ddahlgren]

There are much better ones out there for the same money. The real question is how many things do you want to log for how long and how many times per second. ex.. shocks need 200 minimum to learn anything at all. engine temp once per second is fine same for oil temp or air temp unless a turbo engine and then 20.. TPS MAP Fuel pressure and O2 20 to 50 a second if you want to learn something that is more than a trend.. You are not going to do that with a LM-1 or most any cheap data logger.. You have to match logging speed with sensor response and the Nyquist frequency in mind as well. Beware of bad data it is worse than none as it can steer you down a road that is not going to be pleasant.

Knowing what to do with the data is equally helpful as sometimes the lambda and EGT tell you things you might not comprehend at first. A known realistic starting point is a good first start and then use these to fine tune the setup a wise choice and lots of fresh plugs for an occasional reality check never hurts as well. Generally you might find you go faster with a realistic tuneup and then work on the vehicle. On your bike there is more speed to be found with rider position and angle of attack of the bike than all the jet changes combined if it is jetted even close.
Dave

[Dean Los Angeles]

To help filter what you need, you need to set priorities.

Price. It's easy to get into the deep end of the pool and spend thousands with all sorts of nifty functions that may not be useful. Set the max you want to spend.

Determine what you need for now and the future. A/F ratio and EGT won't do you much good without being able to forecast weather conditions to be able to jet to the proper A/F ratio. Research now saves you money later. Search here first. There have been lots of posts on weather and gages. Additional analog inputs can be hooked to a lot of different sensors, but you have to know in advance. If you put a turbo on it and acquire a boost gage, what is the output?

Plug color was the weapon of choice for a lot of years. If you want to dive into A/F and EGT you have to do the research to know what those numbers are going to relate to BEFORE it all melts.

I use the Digitron 50 on my two-stroke. EGT, water temp, tach, and speedo work for me, but it also data logs. I can not only dump it to the computer, but I can play it back right on the gage. As important as maximum RPM is the RPM at shift points to see if you are shifting at the right point. When did the EGT or water temp reach a certain temperature? Do I need more - or less - cooling?

Search for the threads on GPS here. The Garmin Etrex Legend I use tracks speed accurately over the entire run and can be downloaded and graphed.

No such thing as too little info.

In the thread on Tuning an FI Motorcycle, Kent mentioned the Aim Motorsports DaVid system. Data and video. Two channels of video and data in one video screen. You can watch the run and the data at the same time. Only $2,500 plus the data side. See what I mean about the deep end of the pool?

[hotrod]

There are much better ones out there for the same money. The real question is how many things do you want to log for how long and how many times per second. ex.. shocks need 200 minimum to learn anything at all. engine temp once per second is fine same for oil temp or air temp unless a turbo engine and then 20.. TPS MAP Fuel pressure and O2 20 to 50 a second if you want to learn something that is more than a trend.. You are not going to do that with a LM-1 or most any cheap data logger.. You have to match logging speed with sensor response and the Nyquist frequency in mind as well. Beware of bad data it is worse than none as it can steer you down a road that is not going to be pleasant.

I agree completely regarding bad data is worse than no data!
I think the difference here is unspoken assumptions regarding logging and what a person needs.

Many of us simply need 'some info' vs 'no info'. As you commented above, you need to use caution when you are running a bare bones system and simple double checks like reading plugs are also a good idea.

For those of us with Modern OBDII ECUs, there are engine logging systems that use the native ECU data at sample rates of as low as 15 ms if you don't log too much data. The LM1 as I use it, is a sensor, not a logger, although there is a 6 channel logging ability at 12 samples a second. Between the two that allows high data rate sampling of things like Manifold absolute pressure, throttle postion, ignition timing, injector duty cycle, knock correction etc. and all the other key engine parameters plus the data available from the LM1 sensor, and the additional 5 data channels if needed for functions not available from the ECU.

High data rate sampling for things like suspension dynamics (shocks ride height etc.) would need special consideration.

For the guy on a budget, a modular system built as you can afford it is a lot better than no system.

That Garmin Etrex Legend mentioned by Dean certainly looks like something to investigate as well.

Larry

[DKA]

Matt,
I've thought about putting one on my bike just to get info.  But like a lot of folks are saying... info is only as good as it is and sometimes it ain't.  Anyway here is a site with some test of widebands and meters.
http://www.fordmuscle.com/archives/2007/06/WidebandShootout/index.php.  I am looking forward to talking to you at Speedweek.
David

[ddahlgren]

Sorry to say but the AIM stuff is the shallow end of the pool it gets much deeper than 2500... LOL Just depends on what you want to learn at the end of the day and how important the info is to you. I have done data acq systems in the 20k range on a pretty regular basis and still needed to know more..
Dave

[Sumner]

Matt,
I've thought about putting one on my bike just to get info.  But like a lot of folks are saying... info is only as good as it is and sometimes it ain't.  Anyway here is a site with some test of widebands and meters.
http://www.fordmuscle.com/archives/2007/06/WidebandShootout/index.php.  I am looking forward to talking to you at Speedweek.
David

Thanks for the link.  Looks like Innovate's LM-1 came out on top and is the only one that is self calibrating.  One of the reasons all of the wideband units are so expensive is they have to be calibrated to the specific O2 sensor you are using and they have to control that O2 sensor.  Much more complicated than running a narrow band O2 sensor that is only really good for running one air fuel ratio of 14.7 to 1, which is all a daily driven car needs to run at.

Since these wideband sensors can run on leaded fuel and other fuels than gas in a race car their life will be much shorter than in a street car, but still long enough to give us useful service.  The problem is during their life the sensor will change and for accurate readings and to know when the sensor is no longer good the control unit has to be able to re-calibrate to the deteriorating sensor.  With the LM-1 you push a button on the front and you can calibrate to the air where you are which is also changing with altitude and weather conditions.

If you are going to run a wideband the info on that link and on Innovate's site is good to read.  As the article says:

Of particular note was the issue of re-calibration. All of the units certainly rely on the factory calibration of the sensor from Bosch. The manufacturers may even perform some sort of a calibration of the sensor to their units during their assembly process. However, as far as we could tell, only two units appeared to be capable of re-calibration to compensate for sensor wear. The Innovate unit is self calibrating, while the NGK requires the user to turn a knob until the display reads "CAL." Both measure the air-fuel ratio of free air to calibrate the sensor.

This raised the obvious question: If a unit is not capable of calibration, how does the user know when the sensor is going bad? We know from the Bosch data that the sensors themselves change as they age.

We started with the LM-1 (wide band controller and able to data log 5 inputs) and added the LMA-3 (has built in 3-Bar MAP/Boost, RPM converter, EGT/CHT, 2-Axis Accelerometer and more). 

If I was starting from scratch and wanted to data log, remember we are talking data logging here and not engine management, I would get the DL-32 that has up to 32 channels of data recording and has built into it Horsepower and torque calculation, 1 to 3-bar pressure sensor, EGT/CHT Thermocouple amplifier, Duty cycle sensor, 2-axis accelerometer, RPM converter, 5V power supply for external sensors, 3 solenoid/relay outputs, expansion inputs for GPS and video camera, and the channels can be used for any 5 volt sensors on the car or bike.  The data from the DL-32 is recorded onto whatever size SD card you want to use and then read that card with your computer and their Logworks program will graph it all out for you and that software has lots of options.

You then hook up a standalone wideband LC-1 controller for the O2 sensor and that will be data logged by the DL-32.  With this method you can hook up multiple LC-1's to the DL-32 if you want to data log the air/fuel on multiple banks or cylinders.  The LC-1 can interface directly with most dynos, ECUs, and data recorders on the market along with sending data to the DL-32.

You can get the LC-1 and DL-32 for about $700 for both.  Personally for those of us on a budget I don't think you can get this much accurate data logging from anyone else in this price range.

c ya,

Sum

[MattS]

Matt,
I've thought about putting one on my bike just to get info.  But like a lot of folks are saying... info is only as good as it is and sometimes it ain't.  Anyway here is a site with some test of widebands and meters.
http://www.fordmuscle.com/archives/2007/06/WidebandShootout/index.php.  I am looking forward to talking to you at Speedweek.
David

Looking forward to see your BSA also. Have you run at Maxton this year?

Sorry to say but the AIM stuff is the shallow end of the pool it gets much deeper than 2500... LOL Just depends on what you want to learn at the end of the day and how important the info is to you. I have done data acq systems in the 20k range on a pretty regular basis and still needed to know more..
Dave

I understand there are some great data systems around, I just can't spend $20k on something for a $3500 bike going around 100 mph. Wish I could though. I'm sure my equipment will get better as my speed, and budget, increases. I'm just taking baby steps.....




Matt

[ddahlgren]

I followed the link to the shootout did anyone read the comments sent in at the end?? all those problems exist along with many more in that 'test'...
Dave