Mike Chaney's Tech Corner

Even for runs one right after the other, same place, just about the same time, the numbers and graphs are totally different. Not minor differences either, like 30-50hp. Is this a program glitch?

Thanks Mike.

I'd need details such as what car, what tool (Predator I guess?), and are you logging the engine runtime parameter.  Also would help if you posted a couple of graphs showing the difference.  It's possible your numbers really are different by 30-50hp.  You may have KR on some runs but not others.  Heat soak can eat at least 20hp.  Etc.  I can't diagnose anything when I have no information.  I seriously doubt it's a program problem though.  Your car is either varying that much or something is wrong with the logging (like you chose way too many parameters and your logging is too slow).  I just need more info to be able to help.

Mike

Try these: Its an 08 Jeep SRT8. Logging just 5 Parameters with a Trinity; Runtime, RPM, Speedx64, ST KR, TPS.

(http://i99.photobucket.com/albums/l283/mike00gtp/medqual1.jpg)

(http://i99.photobucket.com/albums/l283/mike00gtp/medqual2.jpg)

Tell me a little about these runs because they look like they were done in different gears.  The torque multiplier on the top graph is 11 while the bottom one is 5.  That means the gearing was way different for these two runs.  The first one looks like first gear and the second one looks like second or third.  Be sure you are using the counter at the bottom to scroll through the runs detected in the log.  If you accelerated through more than one gear, the software will try to split the log into one run per gear.  I fear you are picking up a second gear run on one log and a first gear run on another log.  It's best to make a run in only one gear if you can, lifting the throttle at the end.  That way it isn't confusing as to which "run" is being used.

Regards,
Mike