Query regarding Hp v/s BHP ?

Ford Rocam · 17th September 2005, 00:57

I have a query regarding Hp figures, e.g when we say Scoda RS is 150 BHP does it mean the power is at crank/flywheel or drive wheel ?

also how do we calculate the losses occured when power is transferred from flywheel to drive wheel ?

Mpower · 17th September 2005, 03:28

Its always at the crank unless mentioned otherwise. Usually its 15% loss for FWD cars, little more for RWD and then some for permanent AWD.

turbo_lover · 17th September 2005, 08:33

all BHP figures are at crank .. power delivered at the wheels is much lesser (transmission loss)

pranil · 17th September 2005, 10:15

read OD of Sept . They have a great shootout of all indian bikes on dyno where the claimed BHP at Crank by manufacturer and the actual BHP at wheel is mentioned

GTO - Touring · 17th September 2005, 11:43

Manufacturers quote the crank figures for obvious reasons : Its a BIGGER number

GTO

hkanitkar · 18th September 2005, 00:16

can someone elaborate relation between PS and HP or BHP here ?
is that unit set as standard by the automotive industry because i guess 1 year back all the figures about power output of car used to be in BHP and now some magazines ( may be all ) give these in PS ?

veyron1 · 18th September 2005, 14:28

Quote:

can someone elaborate relation between PS and HP or BHP here ?

1 ps (pferdestarke) = 0.986 bhp, or 1 bhp = 1.014 ps....

one is a standard german unit (ps), whereas the other is a non-metric SAE (society of automotive engineers) unit (bhp)...

also, when converted to watts, or S.I unit in power,
1 ps= 735.5 watts,
1 bhp= 746 watts....

Abhay · 19th September 2005, 15:48

Agaiin same reason to use PS..makes the HP figure look fatter :-)

veyron1 · 19th September 2005, 21:31

Quote:

Agaiin same reason to use PS..makes the HP figure look fatter

actually, it's the other way around- a certain bhp is lesser than the same quantity in ps- for example, 100 bhp= 101.4 ps, or in manufacturer's terms, 102 ps....which means that the main reason for the manufacturers to quote their figures in ps instead of bhp nowadays, is to make the car seem more powerful than it actually is; so ps makes hp figures look thinner...

Abhay · 22nd September 2005, 12:42

Isnt that the same as what I said veyron ?
I said they use PS to make the actual HP figure look bigger than bhp

navin · 22nd September 2005, 14:33

yeah if they could they'd state the figures in watts! who knows what'll come next; PMPO for engines??? :-)

vincentt · 29th August 2006, 20:33

Thanks veyron1, your description of the stuff was quite good. it helps to konw this figures as well.

Manufacturers are that means cheating us ... hmm.. they are giving us the crankcase figures and not the real ones. Even in cars ????

I read the OD of September, and was really shocked to see the results actually. So much difference in many of the top end bikes.!!!

jat · 6th October 2006, 20:59

Quote:

Originally Posted by vincentt

Thanks veyron1, your description of the stuff was quite good. it helps to konw this figures as well.

Manufacturers are that means cheating us ... hmm.. they are giving us the crankcase figures and not the real ones. Even in cars ????

I read the OD of September, and was really shocked to see the results actually. So much difference in many of the top end bikes.!!!

Manufacturers are not cheating. PS is the metric standard being used as it closer to BHP. It is simply 75 kg of mass moved through 1g that is 75 x 9.80665. Makes other calculations simple. Many countries are moving towards SI unit which is KW. This makes calculation and comparison even simpler.

1self · 9th October 2006, 08:20

Quote:

Originally Posted by navin

yeah if they could they'd state the figures in watts! who knows what'll come next; PMPO for engines??? :-)

i totally agree with navin...these manufacturers are bound to come up with something like this...well said!!

Shan2nu · 9th October 2006, 11:37

U know manufacturers are cheating, when their adverts mention their cars with PS and the competition with BHP.

Quote:

also how do we calculate the losses occured when power is transferred from flywheel to drive wheel ?

A dyno test should give you the answer.

Shan2nu

17th September 2005, 00:57	#1
Ford Rocam BHPian Join Date: Feb 2005 Location: Mumbai-India Posts: 878 Thanked: 23 Times	Query regarding Hp v/s BHP ? I have a query regarding Hp figures, e.g when we say Scoda RS is 150 BHP does it mean the power is at crank/flywheel or drive wheel ? also how do we calculate the losses occured when power is transferred from flywheel to drive wheel ? Last edited by Ford Rocam : 17th September 2005 at 01:15.
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17th September 2005, 03:28	#2
Mpower Senior - BHPian Join Date: Mar 2005 Location: Bangalore Posts: 10,409 Thanked: 1,730 Times View My Garage	Its always at the crank unless mentioned otherwise. Usually its 15% loss for FWD cars, little more for RWD and then some for permanent AWD.
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17th September 2005, 08:33	#3
turbo_lover Senior - BHPian Join Date: Dec 2004 Location: Toronto Posts: 1,377 Thanked: 9 Times	all BHP figures are at crank .. power delivered at the wheels is much lesser (transmission loss)
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17th September 2005, 10:15	#4
pranil BHPian Join Date: Mar 2005 Location: Navi Mumbai Posts: 153 Thanked: 2 Times	OD of sept read OD of Sept . They have a great shootout of all indian bikes on dyno where the claimed BHP at Crank by manufacturer and the actual BHP at wheel is mentioned
	() Thanks

17th September 2005, 11:43	#5
GTO - Touring BHPian Join Date: Aug 2004 Location: Mumbai Posts: 710 Thanked: 54 Times	Manufacturers quote the crank figures for obvious reasons : Its a BIGGER number GTO
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18th September 2005, 00:16	#6
hkanitkar BHPian Join Date: Apr 2005 Location: pune Posts: 668 Thanked: 109 Times View My Garage	(BHP or HP) to PS can someone elaborate relation between PS and HP or BHP here ? is that unit set as standard by the automotive industry because i guess 1 year back all the figures about power output of car used to be in BHP and now some magazines ( may be all ) give these in PS ?
	() Thanks

19th September 2005, 15:48	#8
Abhay BHPian Join Date: Apr 2005 Location: Pune Posts: 727 Thanked: 11 Times	Agaiin same reason to use PS..makes the HP figure look fatter :-)
	() Thanks

22nd September 2005, 12:42	#10
Abhay BHPian Join Date: Apr 2005 Location: Pune Posts: 727 Thanked: 11 Times	Isnt that the same as what I said veyron ? I said they use PS to make the actual HP figure look bigger than bhp
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22nd September 2005, 14:33	#11
navin Team-BHP Support Join Date: Mar 2004 Location: Mumbai Posts: 25,187 Thanked: 9,277 Times	yeah if they could they'd state the figures in watts! who knows what'll come next; PMPO for engines??? :-)
	() Thanks

29th August 2006, 20:33	#12
vincentt BHPian Join Date: Aug 2006 Location: Bangalore Posts: 70 Thanked: Once	Thanks veyron1, your description of the stuff was quite good. it helps to konw this figures as well. Manufacturers are that means cheating us ... hmm.. they are giving us the crankcase figures and not the real ones. Even in cars ???? I read the OD of September, and was really shocked to see the results actually. So much difference in many of the top end bikes.!!!
	() Thanks