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Rpm differences

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(@slowstang89)
Posts: 35
Member
Topic starter
 

I keep getting very inconsistent readings from my dyno...I have narrowed it down to Rpm...I am holding the Rpm about 2500 when setting it up..but when I pull the motor to max Rpm around 4500 it always about 5 to 800 rpm off ..so when the motor is at 4500rpm the Dyno software is only reading around 3700 rpm...I have tried to re input the Rpm but keep getting the same result...any ideas???

 
Posted : 23/12/2018 12:44 am
(@admin)
Posts: 1457
Member Admin
 

Hi,

Are you positive the dimensions of the trigger wheel are per the spec here:  https://yourdyno.com/rpm-sensors/. Note if your trigger wheel has rounded slots, you need to measure the required slot width (min 10.16mm) not at the top of the teeth but 5.06mm (the required tooth height) down from the top. Also note the target thickness needs to be 6.35mm or more everywhere, also at the top of the teeth. 

If you send me a raw log file and I can check if it misses pulses from the trigger wheel. 

 
Posted : 23/12/2018 1:10 am
(@slowstang89)
Posts: 35
Member
Topic starter
 

It has round slots but everything else is in spec...how do I get the raw log file? I will definitely send it I tired of messing with it..

 
Posted : 23/12/2018 1:31 am
(@slowstang89)
Posts: 35
Member
Topic starter
 
Posted by: admin

Hi,

Are you positive the dimensions of the trigger wheel are per the spec here:  https://yourdyno.com/rpm-sensors/. Note if your trigger wheel has rounded slots, you need to measure the required slot width (min 10.16mm) not at the top of the teeth but 5.06mm (the required tooth height) down from the top. Also note the target thickness needs to be 6.35mm or more everywhere, also at the top of the teeth. 

If you send me a raw log file and I can check if it misses pulses from the trigger wheel. 

 

 
Posted : 23/12/2018 2:29 am
(@slowstang89)
Posts: 35
Member
Topic starter
 

Is that what your wanting?

 
Posted : 23/12/2018 2:31 am
(@admin)
Posts: 1457
Member Admin
 

Yes, send me the file.

 
Posted : 23/12/2018 9:49 am
(@admin)
Posts: 1457
Member Admin
 

It is not that round slots are not "allowed", as long as it is within spec. Just measure carefully, it is not as easy to measure when the slots are round. Looking at the pic you sent of the trigger wheel it does not look right (but I cannot judge without measurements). 

 
Posted : 23/12/2018 9:51 am
(@slowstang89)
Posts: 35
Member
Topic starter
 
Posted by: admin

It is not that round slots are not "allowed", as long as it is within spec. Just measure carefully, it is not as easy to measure when the slots are round. Looking at the pic you sent of the trigger wheel it does not look right (but I cannot judge without measurements). 

I am emailing you the file now

 
Posted : 23/12/2018 2:51 pm
(@slowstang89)
Posts: 35
Member
Topic starter
 
Posted by: radics1

Did you fix this? I experienced something similar. My target wheel is really off the spec,it has 100 tooths on 104mm diameter,so they are really close,but i use a different hall sensor.

Not really anything for sure...with some help I have narrowed it down my trigger wheel...I'm waiting on a new one now..

 
Posted : 27/12/2018 8:39 pm
(@slowstang89)
Posts: 35
Member
Topic starter
 
Posted by: radics1

Was it missing some teeths? What i experienced: Calibrated at 3000,started power run at 2000 to 5700,which in reality was 2500 and 5900. Of course,mine can be a bad calibration,didnt had time during xmas to make another test.

It just had some differences from one tooth to the next...

 
Posted : 27/12/2018 9:14 pm
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