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Dyno results?


yenko

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I read on on of the links from this website that the 4.6 northstar is was not putting out 295 horsepower on the dyno as claimed, but was putting out somthing like 212 HP. Is this true with all northstars or did I not read it correctly, because that would be a big disapointment. http://www.caddyinfo.com/northstardyno.htm

IMPORT CRUSHER

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It´s a great difference in the horsepower reading you get directly on the crankshaft and the horsepower reading you get on the wheels. The figures that you see for any car almost always is the power the engine delivers directly at the crankshaft.

If I´m not mistaken I think that the SAE system (at least the standard commonly used by Volvo) showed the power on the crankshaft without accessories like alternator, fans, AC and other power-consuming bolt ons. And without mufflers, cats etc.

There where also another standard the used to use, a DIN standard that showed the power delivered at the crankshaft WITH all accessories bolted on. It used to make a difference of about 10%.

An exemple from ancient history ;)

Volvo had an engine B16 rated at 60 hp DIN, its successor B18 were rated at 75 hp SAE (witch only equaled about 68 hp DIN)

When you read the power with a dyno you get what the car truly delivers at the wheels with all losses, both mechanical and others.

You get losses in your transmission that seems to be about 25-30% for the Northstar system.

But anyway, no matter what method used to measure power, the important thing is that you use the same standards when you compare two different vehicles.

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The 295 hp is the power measured at the crank while the 216 hp is what's measured on the front driving wheels. There is always some loss from the transmission, differential, wheel bearings, etc. In this case, 295-216=79hp is lost before it hits the driving wheels.

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Jan, thanks that was good info., I was mistaken in my mind when I thought it was power at the rear wheels. I was under the impression that in the early 70s that was the reason for the huge drop in horsepower ratings, that they measured it at the rear wheels. Thx

Early on sailors navigated by the stars at night and the North star became the symbol for finding ones way home. Once you know where the Northstar is you can point your ship in the right direction to get home. So the star became a symbol for finding ones way home or more symbolically even finding ones path in life.

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Yes. there was changes in rating, and mandated emission regulations can be factored in. Another reason was the manafacturer lied about horsepower. Insruance companies were charging outlandish premiums for high horsepower cars. (For anyone who is old enough to remember, does anyone recall the "If over 375 hp, please specify" statement that all insrurance compaines included in vehicle information?) The solution was to lie about hp, and the "changes in rating" was an excellent way in which to cover the facts. Dyno tests offer conclusive proof that many engines produced a lot more horsepower than the factory rating claimed. In other words, the manafacturer simply rated some of their engines lower than the "over 375 hp please specify."

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