# Advanced Engineering Tech - A "fairer" dyno comparison

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MrMixnMatch
06-07-2012, 10:46 PM
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.

Grr
06-07-2012, 11:43 PM
anyone that knows what they are looking at will compare average hp and tq over a set RPM range, it is very common and can be printed out right on the spot

MrMixnMatch
06-08-2012, 09:04 AM
Ah, right. So what you're saying is... my post was useless. Lol

Guess we gotta start somewhere!

Old SStroker
06-09-2012, 11:35 AM
Ah, right. So what you're saying is... my post was useless. Lol

Guess we gotta start somewhere!

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

MrMixnMatch
06-09-2012, 08:54 PM
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

Right! That's a little bit further than what I was thinking, but I think you definitely caught right on.

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.

Old SStroker
06-14-2012, 09:35 AM
Btw... You sound very much like my philosophy teacher from last semester. It's quite odd. Lol.

Prof. Akston?

Philosophy and physics...what an interesting combination.

Who is John Galt?