Quote:
Originally Posted by patrickt
Great quote -- and contrary to what you see bragged about in a lot of forums.  |
This is a red herring, Patrick and everyone else reading this article. You get flat torque curves with electric motors and supercharged automotive engines among others.
I can tell you from first hand experience that an engine with a flat torque curve from low speed to high speed will not have very poor average power. I own three cars with table flat torque curves. One car is a supercharged BMW, one is a Tesla and one is my Cobra. The BMW produces 480 or 490 (don't remember which) ft/lbs of torque at 1800 rpm. The Tesla is simply a typical electric motor with the table flat torque curve they offer. If I remember correctly it is something like 440 or 450 ft/lbs of torque everywhere. My Cobra has 630 ftlbs of torque at 2000 rpm, and ~580 at 7000. With the exception of the Cobra numbers all of these are at the crank. The Cobra is at the tire.
None of these cars is a shrinking violet in the acceleration department and the Cobra's acceleration will instill fear into most all passengers but then most Cobra's can do that just not as quickly or thoroughly.
Data collection and analysis are two different skills sometimes present in a single person, if he was properly schooled. The author's representation that horsepower is,
"Horsepower in automotive terms is the application of a force at a certain speed." is in fact a mis-statement. Building off a misstatement and attempting to draw valid conclusions from data and processes that are not understood is the short way to confusion and incorrect answers.
Horsepower is historically defined as the the power needed to raise 550 pounds a distance of one foot in one second or the power needed to move 33,000 pounds a distance of one foot in one minute. Neither is incorrect. Significantly, neither is what the author clumsily stated.
A more precise (and accurate) definition is that, a horsepower (hp) is a unit expressed in the foot-pound-second (fps) system, and frequently used to express the rate at which mechanical energy is expended. It is also equal to 750 watts.
The author's definition allows him to misinform his reader and simultaneously misdirect a potential enthusiast that has not had schooling in the physical sciences to assist him in sifting fiction from fact.
The Subaru WRX cars had stunningly high power but poor day to day drivability because they lacked torque, most significantly low speed torque. In dragstrip performance, where engine rpm was maintained high, they would surprise observers with their performance. On the road as a daily driver where the engine was not at high "C" they disappointed owners in droves. The issue was the lack of low speed torque everywhere but the availability of high operating engine speeds.
A high, broad and flat torque curve from off idle to peak engine rpm is simply unapproachable with any power source that has an initial low but rising torque curve that declines at some point further up the operating range for the engine before peak power.
There is a reason that supercharged engines are provided different classes to compete in than n/a engines.
Ed
33Likes
Threaded Mode
