CR 85 in a JB mod chassis

[machwon]

Here's a stock CR 85 motor with a DEP pipe. Yeah probably has some RB porting and head mod too.

[jcs003]

the HP is nice but why is the torque so low? on alot of two strokes i tend to see about a 30% offset of torque to HP.

john

[machwon]

John, when you graph tq and hp over the rpm range the graph will not show a linear 30% increase. Because the HP is being calculated as a function of torque the only time torque equals hp is around 5250 rpms (I don't have the exact number in front of me). Otherwise torque usually remains fairly consistent while the HP always grows because of the RPM's increasing until it falls out of the pipe. Perhaps the graph you were viewing had a short rpm range?

[jcs003]

i see. i know the 5250 is a constant where the torque and HP curves intersect. is their a correction in the program to adjust for the load changes on the dyno? sorry if the questions are vague, im ignorant to dyno technology.

john

[machwon]

The std correction factor was used for those runs. The correction factors do not factor in load but are there to correct to standard temperature and pressure.

[#404's Dad]

The typical display factors of a Dynojet Dyno used are STD and Smoothing 5 for the most accurate info, the lower the smoothing # used will most times show a slightly higher number with its small short spikes. Numbers look pretty typical and in line with most builders CR motors of today though :cool: