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1 horsepower = 746 watts (or around 750 in any case)
I believe this has been around since the 1700's and in pretty much a standard physics equation. 1 horsepower in australia should equal 1 horsepower in North America.

Do the major manufacturers use kilowatts and newton-meters in Australia ? That could be another explination for what you were told. Maybe by "australian hp" he meant KW (100 hp = 75 KW). I think this is most likely.

You mention gross and net hp. This could cause a difference in numbers. The actual unit of measurement is the same, but the way the test is conducted is different. However, it doesn't really matter where you live, you can do a dyno test with any combination of accessories, air intake and exhuast that you want, whether it falls under 'gross' standards or 'net' standards. Just make sure to specify your dyno set-up if you're trying to compare numbers with someone else.

<font size=-1>[ This Message was edited by: btc on 5/14/03 4:14pm ]</font>
 

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I believe the definition of 1 hp is the same everywhere (not 100% sure though), but it's the measuring method that differs. It can differ in the amount of accesories, air filter, exhaust system and the temperature and the correction factors (or atmospheric pressure and temperature).

SAE gross (sixties style) typically gives the highest readings.
 

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no, they are different readings. its like the same as inches to centimeters or yards to meters and so on. but im not sure what the conversion ratio is between the horsepower measurements.
 

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From an engineering standpoint we got the Hp measure from the brits so it shouldn't differ from theirs. We still call it the english system even though I keep seeing Watts and such over there.
 

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In UK we have a saying that "everything goes faster/makes more power in the US"

Maybe we are entitled to be a bit cynical about 500hp crate engines which can't push 400hp when they arrive , especially when the import duty and VAT adds 25% to the price of the part and the shipping.

Or maybe we should just accept that the auto-performance industry has reputable and disreputable operators because HP sells.

There is truth in the saying at the very highest level , the 300mph terminal speed for a top fueler was only attained in Europe about 2 years ago.
 

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Perhaps you guys need to learn how to tune?


When I lived in Germany I had a 1980 Ford transit van. 2.0L,points ign, straight axle front end! haha
Anyway, the slight miss at idle pissed me off as well as the poor accelleration. I put in electronic ign out of a 2.3L mustang/carb off a 3.2L bmw/etc. You could reach in the window and hit the key and it would fire up and idle smooth with no odd miss or skip. Then I went for a drive and it wouldn't rev well past 4000 and overheated, missing and banging above 4500. I got a boxhead to look at it,he set the carb and advance etc all at 5000. Idled like sh!t, but he said your not allowed to idle at lights anyway so who cares?
Point is, we tune one way and you guys might tune another. I had to fix a ford exp(2 seat escort here) when the guy put in points and twin webers on advise of a boxhead, then wondered why it was hard starting and sluggish and only worked well on the autobahn........
 

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Power in hp is the same everywhere but there are lots of different correction factors even here in the USA like the STD or SAE ones so the corrected power does change somewhat. The American STD is VERY generous and that's what you are quoted off most engine dynos. The European standards are tighter as is the newer SAE standard.
 

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They are different and were devised differently as well. Americans se what is called a Imperial or Mechanical hp and is defined as exactly 746 W , while the britts use an metruc hp which is defined by the power to raise 75 kilo up 1 meter in 1 second or 735.5 W. The American number comes from equaling 33,000 ft*lbft/min (some unit maths leads to 746W) which is a number derived by James Watt and what it took one horse to turn some machine way back. It was actually different as 3 was used for Pi but the 33,000 still isn't correct for a more perfect def of pi so who knows where he pulled that one out from. Watt did his work in Oxford so yes the hp comes from England yet they went and changed what they used.
 

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They are different and were devised differently as well. Americans se what is called a Imperial or Mechanical hp and is defined as exactly 746 W , while the britts use an metruc hp which is defined by the power to raise 75 kilo up 1 meter in 1 second or 735.5 W. The American number comes from equaling 33,000 ft*lbft/min (some unit maths leads to 746W) which is a number derived by James Watt and what it took one horse to turn some machine way back. It was actually different as 3 was used for Pi but the 33,000 still isn't correct for a more perfect def of pi so who knows where he pulled that one out from. Watt did his work in Oxford so yes the hp comes from England yet they went and changed what they used.
Please excuse my poor typing. I'm on a tablet.
 
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