EVO Magazine hit the dyno with their 550

and were pleasantly surprised after 5 years it pulled 482 BHP !

 

RWHP? That sounds high.

 

No at the flywheel. At the wheel it was 394.5 hp

 

Mine pulled 486hp (calculated) at the flywheel on the same brand of dyno a year ago. Just goes to show the consistency of the Dyno Dynamics dyno.

 

Impressive....

 

If its at the flywheel its not BHP ? Or am I wrong ? :$

 

No it is, flywheel horsepower is BHP (brake horsepower) also called SAE net horsepower. (Used in America & UK for example.)

At the dyno is RWHP, or rear wheel horsepower.

 

Technically BHP or brake horsepower refers to HP at the output shaft (the crank) in reference to prony brakes they used to measure torque (and thereby horsepower) in the old days. Flywheel HP is somewhat lower than BHP due to mechanical losses from rotating the flywheel mass.

Since they don't use prony brakes anymore, these days BHP has come to mean HP at the flywheel.

 

Thanks

 

Glad you said the last part....
America, the UK and others use SAE net or bhp to get there ratings. These are both basically the same. The get the numbers from a test with all accessories and exhaust. A crankshaft/flywheel number is used. Some other countries use Kilowatts which when converted to there horsepower figures (usually max power) yeild a slightly higher number. Hence why sometimes you hear 490 hp for the F430, and other times you hear 483 hp for the F430. 483 hp is the more accurate rating though since the procedure is much better.

 

So if you say the 430 has 490hp, its the same as 490bhp ? Some people just phrase it differently ? I know Ive always said bhp.

 

Well it depends, BUT if you use bhp, then it's 483 bhp. 490 is "max power" or PS.

 

As an expat Aussie, I was taught that kW is just another unit of power that has no relation to how it is measured. If it gets 483hp, then that is simply .746 x 483 = 360.3kW. It does not matter how you measure it, you can express it as either kW or hp. Measure it "wrong" it does not matter how you express it, it is still "wrong".

I would have thought that any HP differences between countries has more to do with different emisions and fuel qualities...

I could be wrong on both these - happens all the time

 

If a car is measured in kW, that converts to DIN "max power" hp.
SAE net hp or bhp, which is used by America and the UK for example
use more accurate and more efficient tests so the number will
be a little lower. That is why many new cars have two ratings. A DIN "max power" hp, kW rating....and a SAE net hp, bhp rating. The latter is much more up to date. The SAE net hp rating was just upgrading a few months back as a matter of fact.

 

On all the dyno's I have used, you can choose whether to display power as SAE or DIN and in either HP or kW. I thought there was simply a conversion ration between the SAE and DIN ratings, just as in KW and HP. In fact I have a programme, convert.exe, that amongst many other things, can do this.

 

There is a conversion. But all your doing is converting one number to another. If the proper way to achieve that number wasn't used it won't be right. Plus as I said the SAE net hp rating was recently updated. Kind of hard to explain. My friend actually works for the SAE and tells me all the news.