Monitoring Devices

FIRST, the disclaimer.  The information listed here is simply for your entertainment.  Your vehicle's manufacturer does not intend for you to modify your vehicle in any way, or apply any of this information.  The following is just an example of  how  *SOME PEOPLE*  are using monitoring devices and the information they supply, while voiding their warranties.   This is not meant to encourage YOU, or anyone, in any way, to modify a vehicle or void a vehicle warranty.   I am not responsible in any way for damages to your vehicle, as a result of use, misuse or abuse (unless I'm driving it!).  

There are two popular monitoring devices in use by SyTy racers at the track.  The Diacom product and the OTC unit.  The Diacom is discussed here.  If you have an example or text you would like to sumbit on the OTC or others, please tell me about it..

Diacom, by Rhinda Technologies is an excellent monitoring tool for the enthusiast who intends to modify a computerized vehicle.  Besides allowing you to read and inerperate error codes, it allows you to record the "data stream" coming from the vehicle's ECM.   The Diacom product consists of a software package, and a cable that attaches to the ADL connector under the dash.   The other end of the cable attaches to to a PC parallel port (usually a laptop).    The big things to a racer  are the knock-retard (KR) numbers, and the oxygen (O2) sensor readings.   

KNOCK RETARD READINGS:  If there is no absolutely no KR taking place during a dragstrip run, they will either introduce more timing or more boost to find the point at which the engine is "on the threshold" of detonation so to speak.  The 4.3 GM engine can't withstand a great deal of detonation.  Most SyTy racers draw the line (adjust boost, timing, fuel quality, etc.) when they see the knock retard going beyond say, 5 degrees.  Buick racers, on the other hand, have pistons that are considerably more rugged, and typically allow as much as 10 degress of KR. 

OXYGEN SENSOR READINGS:  The O2 sensor is also very impotant.   Different monitoring divices will show different values for this reading.   The Diacom will show an average of around 950 during a "good" run.  If the average is in the 700 range( or below) for a full throttle run, this is generally considered too lean, and can lead to detonation, excessive exhaust tract heat, melted pistons tubine failure, etc.


Download or view:  If you would like to DOWNLOAD or VIEW files of computer data gathered  during a 12 second Syclone run, by an XT laptop running Diacom program, click on the file for Lotus, Dbase or Text versions.  The files are compressed and you'll need an "unzipping" utility like PKUNZIP v.204g or WinZIP.

      1282WK1.zip (26K)          1282DBF.zip (4K)           1282TXT.zip (4K)          View file here!

Notice the sharp drop in the oxygen sensor reading, which was caused by "slosh" in the almost empty gas tank, after the 2-3 shift, resulting in the fuel pick-up drawing some air.   This caused a momentary lean condition.   After this run, it would be wise to go home or put some gas in the tank!  

Drag Strip Run, Stock Syclone, 12.82 ET, ATR Race chip

Click here to see Ron's COOL chip comparisons.

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