Merely 'mentioning' weight as one of the factors in a broad discussion that also mentions every other variable is hardly the same as recognizing that it is *the* determinant, at least when comparing equal rear wheel HP under standardized soil conditions. The post I referenced was the first to do precisely that.
Because it is not the determinate factor, there are multiple factors that will apply.
It is not. Again, drawbar is typically given in horsepower (power), not pounds (force). This has already been discussed in several prior posts in this thread.
I disagree. Once you recognize that "horsepower" *is* the measure potential pulling power, the only remaining variable is the ability to put that power to the ground, i.e., traction. And traction is simply the co-efficient of friction (soil condition and tire construction) x mass (weight delivered to the soil).
Yes... power. But again, pull in a higher gear. You will measure higher pulling power, both due to elimination of tire slippage and due to reduced gearing losses through the drivetrain.
that simple little co-efficient of friction has a 1000 variables, and the mass is not a simple number either a lot of varibles in there depending upon how the weight is biased front to rear and high or low, for just a couple and there are hundreds more.
Think about neither for a moment. Rather, consider pulling on a scale attached to the draw bar which records peak pulling power. Yes, gearing and wheel diameter can be used to multiply the engine torque delivered to the rear wheels, but at a lower speed. Nonetheless, the measure of rear wheel horsepower remains the same (force x distance/time). Against the infinite scale, at some point the tractor's rear tires will break lose, or the engine will stall. That is the point of peak pulling power of that tractor. Adding rear wheel weight may increase the motive force up to the point of stall, decreasing weight may increase motive force by preventing stall. In either case, weight is the determinant.
Maybe if it was a transplanted Detroit 2 stroke
Then it could be a turbo charged super charger engine.
Granted, if the sort of comparison you're after is of the 'my tractor will pull more than your tractor' variety, then the all the factors you mention, and many more, will have an impact on who wins. I guess my understanding of the OP's comment seemed to presume something more akin to a standardized testing scenario, where factors like fuel temp, pulling speed (from rest), tire design, etc., would be consistent among the test candidates.
First time I'd ever heard of a supercharger was when reading the box for a Revell P-38 Lightning my dad built for me when I was about age 5. It was called a turbo-supercharger. Obviously it just means a forced induction device that uses a turbine to drive a compressor, instead of a PTO running a scroll or vane type displacement pump. They all "supercharge" the engine.
I have never heard the term supercharger used as a generic term that includes turbochargers as well.
Agree to disagree. But the context of this thread is about taking drawbar pull readings from different members all over the country, with different tractors, tires, and soil conditions. So no, in the context of this thread, weight is not "the" determinant factor....because equal RWHP and standardized soil conditions are not a factor here.
