The Autonerdz Community Forums | |
https://www.autonerdz.com/cgi/yabb2/YaBB.pl
General Public Area >> PicoScope >> RPM calculation https://www.autonerdz.com/cgi/yabb2/YaBB.pl?num=1543505188 Message started by James on Nov 29th, 2018 at 7:26am |
Title: RPM calculation Post by James on Nov 29th, 2018 at 7:26am
I took the following cmp-ckp capture with this 2000 Volvo idling at approx. 650 RPM.
The markers cover one cam revolution (2 crank revolutions) but RPM states 325RPM. What am I missing? |
Title: Re: RPM calculation Post by James on Nov 29th, 2018 at 8:01am
My thinking being 2 crank revolutions between the markers should equal twice the actual RPM, not half.
EDIT: I figured out my mistake. I knew I was measuring two revolutions of the crank and didn't take into account that the software measures what ever is "between the markers" as a "single" revolution in it's calculation. I was thinking double the revolutions because I was erroneously doing the calculation in my mind of actual revolutions x actual RPM while the software was doing the exact opposite. It is measuring between the marks as one revolution. Since I have two crank revolutions between the marks, it's only counting them as one and thus the RPM shows as half of what the car's actual RPM is. |
The Autonerdz Community Forums » Powered by YaBB 2.5 AE! YaBB Forum Software © 2000-2010. All Rights Reserved. |