Q&A Forum
Hi, i dont know if somebody is having same problem when test cars, normally everything is good but for some cars i have some problems that read some peaks at the end of the pull, i know it's a false Reading, im pretty sure it's about about ramp configuration , i dont think is about when press clutch when pull is done...here a couple of screenshoots.. you can see the loosses readings are peak so that's why i get higher hp (crank) higher at the end. for Wheel power is perfect but here we use a normally hp (crank) readings
Good pulling.
WHP Reading always is good and i can see drivetrain losses Reading is good too..
Now, here become problems..im pretty sure is about ramp setup time but i dont know sometimes if i have to add extra rpm to engine redline or less , you know in Eddy brake dyno, brakes get off BEFORE the target rpm, i means, when you setup rpm ramp, you put second time to rpm, i have this setup :
Time - target rpm
0 - 2500rpm
3 - 2500
15 - 6500
Normally i edit the 3 second target rpm and the 15 second rpm target , according of car to test. For to know what's engine redline i normally get it when i calculate gear ratio, i calculate it then go to redling and see what rpm see yourdyno, ok, then i put to "15 second rpm target" to rpm redling i got of the car. Ok, problem is sometimes i get this peaks.
You can see the peak from 8.600rpm to the end..
It's because i get high drivetraing looses Reading.. as i said, whp Reading is good but it's all about hp (crank) Reading / drivetrain looses
Any idea for to fix it, it happens sometimes only but it's very annoying when this happens since these peaks are not real readings.
Iv been editing the csv files with a app I made to trim the end off them then reopening it in YourDyno. But thats to get rid of the tail end that drops back with rpm.
Maybe a built in solution would be if Jostein added a feature on the "result vs time" tab where you could trim the start and the end off a log.
Walter,
I found the likely reason. In version 3.01.72 and before he brake turned off only when the end of the run was reached in time, as defined by the brake curve. So if you engine leads somewhat the brake curve, then the brake will not turn off immediately when the end RPM is reached. The PID will turn off the brake, but there is a small response time there, so essentially the brake was hanging on for a little bit after the end RPM was reached, which caused the retardation to be higher than it should.
There is a new version now, 3.01.73 where this is fixed. The brake turns off when either the end of the run is reached in time or the end RPM is reached.
Hi Jostein, remember im not using 3.01.72, it doesnt Works properly for my hub dyno, im using the 3.01.68 one that Works good. I dont know this new versión..