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I trust Prelude owners are the smartest of the Honda bunch so I think it's appropriate to post this here
. Anyhoo, I was reading that article that slntsam had posted earlier about hp vs/ torque and came across these lines:

"it will generate some level of torque (340 foot pounds TIMES WHATEVER OVERALL GEARING) at the drive wheels"

"we could run the LT1 at 5000 rpm (where it's making 315 foot pounds of torque), and gear it down to a 12 rpm output. Result? We'd have over *131,000* foot pounds of torque to play with" (he calculates "wheel torque" by using a gear ratio of 1:416.67
)

Which sounds to me like he is saying that the difference between the torque showing at the wheels and the mystery torque number at the crank would be determined by the overall gear ratio. Such as, measured 100 lb/ft at wheels in a gear with 1.5:1 overall ratio would have 150 lb/ft at the crank.

So I'm wondering, (obviously it's oversimplified), but couldn't you use the measured torque and the gear ratio plus some "drag factor" to add in driveline friction to calculate crank torque (and thereby crank hp, what everybody wants to see, even if just for trivia's sake)?

But then I'm confused about how you could get pretty similar torque numbers from two similar cars on dynos with one in 3rd gear and one in 4th. Whats up with that? Does the dyno's computer factor that in? Do they know what gear ratios your car has?

I just want to know more about how these things work. Please think for me, I'm too tired and not smart enough at math/physics
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um, what?
I think I shouldn't have skipped Physics to have an easy senior year of high school.


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well, dyno pulls are done in a gear that is most near a 1:1 ratio. be it 3rd or 4th gear. but basically you've got it right, find torque/horsepower at the wheels, figure in the gearing(if its already real close to 1:1 then why waste the time though?) and then if you had a rough idea of the driveline losses you'd have your crankshaft numbers, although the calculation would only be as good as your worst assumption, but still, in theory.
 
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