Anybody know why some of the dyno plots posted don't show Torque and HP crossing at the 5250 rpm point ?

From my understanding of how HP is calculated :

hp = torque * rpm / 5252

and since dynos measure torque, they should always cross at 5252 rpm beacuse hp is derived from the torque.

 

Generally when that happens, the HP and torque axis are not scaled the same. A simple adjustment of the scales will show the intercept at 5252 rpm.

Speedlimit...

 

How can that be ? HP and Torque are on the Y axis, for example HP on the left, torque on the right. Rpm is common to both plots and is on the x axis.

 

On Dynojet dynos they do because they correct torque which is not SAE standard. SAE corrects only HP so on other dynos which use the official SAE standard they do not cross at any particular RPM unless by coincidence.