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how do dynos work?

immortality

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AirStrike

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torana355

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A dyno measures torque (twisting force) and RPM, power is how much work can be achieved in a specified time and is the relationship between Torque and RPM. The higher the RPM the higher the power depending on the torque at that RPM.

So for example if my SSV makes 400 foot pound of torque at 6000rpm You would calculate power in HP with this equation 400 * 6000 / 5252 = [email protected] 6000rpm

If it was making 300 foot pound of torque at 4000rpm the equation would be 300*4000/5252 [email protected]

This is why diesel cars have alot of torque but not much power, they only rev to around 4-5k and they make maximum torque at low RPM. This is also why rotarys are gutless at low rpm, they have a small amount of torque which means they need to use high rpm to make their power. On the other end of the spectrum a big 6L V8 makes alot of torque at low rpm so they don't need to rev as high to make the same power and if they are built to rev to high rpm they usually make very good power.

Here is a link that explains this very clearly Power and Torque: Understanding the Relationship Between the Two, by EPI Inc.
 
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torana355

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The point of the whole argument is what do dyno's measure, they can't measure power as power is only a calculation based on what is actually measured, which is torque. There is a thread on LS1 that explains it better.

Whatever applies the force is irrelevant as the dyno can't actually quantify it, it can only measure the torque required to spin the rollers.
No dynos measure torque and RPM. Torque on its own would not move a car very far or fast at all. Engines produce power but a dyno does not measure power, yes power has to be calculated but the engine is still producing it or your motor would spin for a few seconds then stop. I hope that made sense lol.
 

Not_An_Abba_Fan

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No dynos measure torque and RPM. Torque on its own would not move a car very far or fast at all. Engines produce power but a dyno does not measure power, yes power has to be calculated but the engine is still producing it or your motor would spin for a few seconds then stop. I hope that made sense lol.
Nobody is arguing that an engine doesn't produce power, the argument is, or my argument is, the power isn't MEASURED, it's calculated by a formula.
 

torana355

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Nobody is arguing that an engine doesn't produce power, the argument is, or my argument is, the power isn't MEASURED, it's calculated by a formula.
In that case i agree 100%
 
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