dyno experience

[D Ingram <d_ingram@xxxxxxxxxxxxxx>]

To all who are interested,
My technical knowledge is somewhat lower than some of you, 
I'm only 21, but having worked on a dyno for about a year, I 
think I might have some useful comments.
There are other factors to consider when calculating hp. 
Outside temperature, barometric pressure, even elevation. The 
actual setting up of the dyno is such a hassle that I'm sure 
some other dyno technicians routinely disregard the procedure.
I don't think there is any sure way of calculating 
engine hp. There is of course drivetrain loss in the 
flywheel, clutch, transmission, driveshaft, diff, 
half-shafts, bearings, wheels - anything that has weight that 
must be moved by the power of the engine. If any of those are 
out of tune or not up to factory specs, wouldn't that lower 
the engine's peak hp?
I think the same reasoning can be applied to the engine 
itself. If the spark plugs are fouled, or any part of the 
ignition is worn, the timing is off, etc. the engine is not 
running at the same level of performance as it did when it 
left the factory. Even the oil in the engine and the transmission/diff 
are said to make a difference.
Am I right or wrong on this?
IMHO, the only sure way to know what modifications work is to spend an 
entire day on a dyno. Try swapping one thing at a time and looking at 
the results of the following run. This may be expensive - but if you 
really want to know (and some of you don't) it's the only way to go.
But remember, this isn't an exact science!

Doug Ingram

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D Ingram
Email: d_ingram@domain.elided
Salem State College

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