Arduino Data Logger Project
08-27-2013, 10:32 PM
#32
Rennlist Member
Thread Starter
First logging runs tonight to capture TB pressure drops. As it is a "Black Box" I am calling it the "Flight Recorder" lol. This little box is going to help me get a handle on the effectiveness of several mods. Tomorrow night I plan to log pressure and temperature across the inter-cooler.
08-27-2013, 11:18 PM
#33
Rennlist Member
Love it! Are you powering the Arduino and sensors with that 9 volt battery? It's nice to have a common ground with the chassis, which comes naturally when you use the car's 12 volt system. I use an LM2940-10 voltage regulator with the two capacitors recommended in its datasheet (you can see the circuit, such as it is, in the speedo calibrator linked below).
Separate topic -- did you tig weld the ports in the pipe yourself?
Separate topic -- did you tig weld the ports in the pipe yourself?
08-28-2013, 09:50 AM
#34
Rennlist Member
Thread Starter
Love it! Are you powering the Arduino and sensors with that 9 volt battery? It's nice to have a common ground with the chassis, which comes naturally when you use the car's 12 volt system. I use an LM2940-10 voltage regulator with the two capacitors recommended in its datasheet (you can see the circuit, such as it is, in the speedo calibrator linked below).
Separate topic -- did you tig weld the ports in the pipe yourself?
Separate topic -- did you tig weld the ports in the pipe yourself?
08-28-2013, 09:18 PM
#35
Rennlist Member
Thread Starter
Pressure drop across my modified inter-cooler at 1 Bar was pretty much 2.2 psi (***correction 1.1 psi ***). Temp data still not right, should have the code sorted by tomorrow.
08-30-2013, 08:59 PM
#36
Rennlist Member
Thread Starter
Tom - Thanks for the info for the GM AIT's. Up and working perfectly. Thanks also for conversion table. 
The "telemetry" component to the Flight Recorder:
http://www.eye.fi/
The "telemetry" component to the Flight Recorder:
http://www.eye.fi/
08-30-2013, 09:35 PM
#37
Rennlist Member
Redoing the math, I think that table was scaled to slightly less than 5 full volts, since that's what I was had. Probably close enough, but if you do the math you'll see what I mean. A couple of folks wrote to me suggesting ways to make the measurements more consistent and accurate (regulated reference voltages for the Vref pin, regulated current supplies, precision resistors, etc.), but the basic approach is good enough I'd say. If you recalculate the table, you can add some accuracy by using the actual/measured values of the resistors in your circuit and perhaps applying your supply 5v to the Vref pin. That would add some accuracy without additional parts or complication.
The eye.fi looks like it will be fun!
The eye.fi looks like it will be fun!
09-01-2013, 11:36 PM
#40
Rennlist Member
Thread Starter
The following chart is a 1 bar run to 5000 rpm in 3rd gear. Ambient temp was about 78F. Gray line is IC inlet (F), Yellow is IC outlet (F), and blue is boost (psig). Higher boost levels runs to redline will be much more useful . Calibration is off a bit as you can see but still interesting none the less.
The M-Tune AIT read 82F before and during the run but jumper a full 10F to 92F immediately after the run. The IC does a very effective job of dumping heat into the engine bay.
The M-Tune AIT read 82F before and during the run but jumper a full 10F to 92F immediately after the run. The IC does a very effective job of dumping heat into the engine bay.
09-02-2013, 12:00 AM
#41
Rennlist Member
Thread Starter
It appears that some pressure waves are taking place messing with my pressure data. I turned up the data rate and got a clearer picture and I think the 2+ psi numbers I was seeing are transient pressure waves of some kind (or a problem with my logger). Looks like around 1.1 psi is more of a consistent average at 1 bar of boost. More data to follow...
07-28-2014, 10:35 PM
#42
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Hi Shawn,
Do you have the Arduino data logger completed. I just found out about the Arduino today and the first thing i thought of was a data logger. I was pleasantly suprised to find that one of the first things that popped up on google was Rennlist AND a 944T.
Do you have the Arduino data logger completed. I just found out about the Arduino today and the first thing i thought of was a data logger. I was pleasantly suprised to find that one of the first things that popped up on google was Rennlist AND a 944T.
07-28-2014, 10:40 PM
#43
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Thread Starter
Yep, I have used my logger extensively. Arduino is awesome. It also powers my flow bench. I think stuff is pretty well documented but let me know if you need anything. Be glad to share my code also. Tom M has also used the Arduino extensively and probably has a better handle on it than me.
07-28-2014, 10:47 PM
#44
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Shawn, your temp data looks pretty similar to mine. At 1 bar I see compressor outlet temps of ~160-170f and ambient temps at the throttle body. Have not measured pressure drop yet but expect it is ~1 psi or less. Keep the data coming!