| Tyandriel |
10-24-2011 03:14 PM |
Quote:
Originally Posted by C4RBON
(Post 66083)
I'm pretty sure some dynos apply real load to the wheels. What you're talking about is using the inertia as the load. There would be a nightmare's worth of assumptions and correction factors necessary to get meaningful results... *snip*
|
yep, you´re right, I have to admit. There are different types of dynos. But loading or inertia is irrelevant, from the mathematical point of view. They differ in the types of variables and measured values. If the numbers are "true", both should spit out the same result.
The loading ones deliver the more exact results in reality, yes. Because more assumed/determined values are measurable ones here. An inertia one with a 60ft diameter roll would deliver reliable results, too, because the relevance of the assumed values is lower.
And the most/nearly all dynos you see on shows or meetings or at the tuner store around the corner are the inertia ones. They´re good enough to test a difference before and after tuning a car at a reasonable pricetag. And to have some nice numbers to show your friends.
That´s also why you often find big differences between the measurements of a car from 3 different dynos.
As Dave said: the "good"/loading dynos show low numbers. Mostly, because the operator is a real Pro and not interested in giving you a tweaked sheet for your smile ;) and if I see bare numbers from a dyno run I don´t believe anything without a look on the graphs.
Nevertheless: all of these dynos work with factors to consider the powertrain. And the result may vary according to these.
A real powersheet of your engine is only measurable on an engine dyno. |
