A "fairer" dyno comparison
06-07-2012, 09:46 PM
#1
On The Tree
Thread Starter
iTrader: (1)
Join Date: May 2012
Location: Mobile, AL
Posts: 140
Likes: 0
Received 0 Likes
on
0 Posts
A "fairer" dyno comparison Not entirely sure where to put this, but I'm gonna go ahead and assume that most people here would know what I'm talking about.
Instead of looking at peak hp/tq, why do we not compare an engine's power as "area under the curve"? Also known as the integral.
I understand that no dyno graphs are simply a function of say e^x, but if you have several points on the graph you are able to do a parabolic/linear/exponential regression which will spit out a function of y and x. If it fails simply make three functions. One increasing to the peak, one negative parabola at the peak, and one decreasing from the peak.
Taking the integral of that/those function(s) should give a more accurate scale of total power made by an engine.
It's really just a random idea I had. I know it's not exactly practical unless it was done automatically by the dyno software, just thought it was an interesting suggestion.
Instead of looking at peak hp/tq, why do we not compare an engine's power as "area under the curve"? Also known as the integral.
I understand that no dyno graphs are simply a function of say e^x, but if you have several points on the graph you are able to do a parabolic/linear/exponential regression which will spit out a function of y and x. If it fails simply make three functions. One increasing to the peak, one negative parabola at the peak, and one decreasing from the peak.
Taking the integral of that/those function(s) should give a more accurate scale of total power made by an engine.
It's really just a random idea I had. I know it's not exactly practical unless it was done automatically by the dyno software, just thought it was an interesting suggestion.
06-09-2012, 10:35 AM
#4
TECH Fanatic
Assuming we are interested in accelerating the vehicle, looking at the torque/power in the rpm range used gives a number of clues to performance.
Average torque/power (in the rpm range) is a fairly good measure of how well the vehicle will accelerate. In a high powered vehicle where wheelspin could be a problem, the shape of the torque curve can tell you where you might encounter wheelspin in the lower gears, or even the higher ones.
If you accept that torque at the drive wheels determines vehicle acceleration, it is an interesting exersize to calculate/plot thrust curves for a vehicle.
Any time we can get people thinking about how and why things work it is a good thing. The more one knows about "how the world works" the easier it is to understand how and why vehicles perform. Mother Nature's rules can't be cheated.
My $.02
Jon
06-09-2012, 07:54 PM
#5
On The Tree
Thread Starter
iTrader: (1)
Join Date: May 2012
Location: Mobile, AL
Posts: 140
Likes: 0
Received 0 Likes
on
0 Posts
Far from useless MrM&M.
Assuming we are interested in accelerating the vehicle, looking at the torque/power in the rpm range used gives a number of clues to performance.
Average torque/power (in the rpm range) is a fairly good measure of how well the vehicle will accelerate. In a high powered vehicle where wheelspin could be a problem, the shape of the torque curve can tell you where you might encounter wheelspin in the lower gears, or even the higher ones.
If you accept that torque at the drive wheels determines vehicle acceleration, it is an interesting exersize to calculate/plot thrust curves for a vehicle.
Any time we can get people thinking about how and why things work it is a good thing. The more one knows about "how the world works" the easier it is to understand how and why vehicles perform. Mother Nature's rules can't be cheated.
My $.02
Jon
Assuming we are interested in accelerating the vehicle, looking at the torque/power in the rpm range used gives a number of clues to performance.
Average torque/power (in the rpm range) is a fairly good measure of how well the vehicle will accelerate. In a high powered vehicle where wheelspin could be a problem, the shape of the torque curve can tell you where you might encounter wheelspin in the lower gears, or even the higher ones.
If you accept that torque at the drive wheels determines vehicle acceleration, it is an interesting exersize to calculate/plot thrust curves for a vehicle.
Any time we can get people thinking about how and why things work it is a good thing. The more one knows about "how the world works" the easier it is to understand how and why vehicles perform. Mother Nature's rules can't be cheated.
My $.02
Jon
Btw... You sound very much like my philosophy teacher from last semester. It's quite odd. Lol I am very thankful for the post though.
06-14-2012, 08:35 AM
#6
TECH Fanatic
