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Dynamometer Scaling (Technical)

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Old Nov 21, 2007 | 06:36 PM
  #1  
kouzman's Avatar
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Dynamometer Scaling (Technical)

Basically this is what i am trying to figure out!

In most of the dynosheets we see, the torgue crosses the power curve at 5252rpm. I know about the formula

hp=(torgue * rpm)/5252

When you have a dynosheet that the two curves DO NOT cross at 5252rpm what could it mean?

For example:

We have a car that its power/torgue curve cross at 5252rpm and its torgue is e.g. 300ft-lbs.

The we have a car that its power/torgue curves cross at 5600rpm and its torgue is 300 ft-lbs again.

Could you say that the first car is making more power/torgue than the second car and if the second car has "pushed" its torgue further up to "make" more power?

Can someone explain to me the basics of rescaling and for what reason?
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Old Nov 21, 2007 | 06:56 PM
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If HP and torque aren't crossing at 5252 RPM, it's wrong. HP is derived from torque and RPM.
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Old Nov 21, 2007 | 07:06 PM
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It means that the scaling on the Y axis is different for torque and horsepower. Look on the right and left side of the graph, one should be HP the other TQ, they will not equal each other given the same location on the Y scale
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Old Nov 21, 2007 | 07:17 PM
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yes but from what i read hp it is calculated from the torgue * rpm devided by 5252. If you change the constant 5252 to 5600 doesn't it change the numbers?

something that i found but it doesn't elaborate why:

http://www.moparengineswest.com/what...no_numbers.htm

Last edited by kouzman; Nov 21, 2007 at 07:25 PM.
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Old Nov 21, 2007 | 08:48 PM
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if you divide by a larger number then you'd get a lower reading right?

now is it higher for points below5.6k and lower for points above? .... no right... just all overlyall lower...
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