Mike,
Before I say anything, I would like to clarify that I think you are one of the best tuners in the business. And you are without question the nicest, most personable tuner anywhere. As a matter of fact, you did the 4 position chip on my old Lightning for me. I loved it. Made great power, got good mileage, and is still going strong. The guy I sold it to still loves it.

All that being said, if you have ever seen any graphs where hp and torque did not cross at 5252, then something was wrong with the calculations or with the scales of the hp and or torque. Why? Well, it has to do with how the term horsepower came to be and the mathematical formulas behind all this stuff. This is the equation.

Horsepower = Torque * RPM / 5252

So how is this formula arrived at, and where did 'horsepower' come from?

Well it's all down to the Scottish engineer James Watt (1736 to 1819), he established that a horse could pull a 550lb weight up from a coal mine at a rate of one foot every second, for an eight hour shift. This converts to 33,000 foot pounds per minute. He published these observations, stating this figure to be the equivalent of one horsepower.

We need to convert from the rotary motion of an engine to a linear motion, like the horse example. Remember we can only measure the torque of the engine, this is expressed in pound feet. A pound foot of torque is the twisting force necessary to support a one pound weight on a weightless horizontal bar, one foot from the center of rotation. Lets rotate the one pound weight one revolution, the distance travel is 6.2832, that's Pi multiplied by the diameter, 2 feet. We have now done 6.2832 foot pound of work.

One horsepower equals 33,000 foot pounds per minute, so if we divide 6.2832 in to 33,000 we can conclude that we at 5252 rpm we are producing one horsepower, we are moving our one pound weight 33,000 feet every minute. Therefore if we multiply the torque by rpm and then divide by 5252 we can calculate the horsepower.

And therefore there is no possible way that the torque and hp can NOT be equal at 5252 RPM's. Again, sometimes they won't cross each other on a given graph due to the scaling of hp being different than the torque. It's all in the math.