convert KW atw to hp (at crank)

[eg9-b16b]

sorry newbie question here.. how to convert KW atw to HP (at engine)..
example how much 127.8 KW atw (this figure I took from DC5 dyno result on other section) if we convert it to HP (at engine)... from my calculation it should be 204.5 HP ...anyone hope you can show some calculations.. also how much for stock DC5R 147KW/200HP (at engine) to KW atw... is it 124.95 KW?... hopefully someone could clarify it for me... cheers

[JDM.Power]

http://www.mr2ownersclub.com/converter.htm

[kazam]

i used 2 have that link ages ago but lost it! good job brah!

[defect]

not sure how accurate this is.

To convert from horsepower to kilowatts, multiply by 0.746.

To convert from kilowatts to horsepower, multiply by 1.34.

[dsp26]

not sure how accurate this is.

To convert from horsepower to kilowatts, multiply by 0.746.

To convert from kilowatts to horsepower, multiply by 1.34.

yeah thats both correct...

1.3405 though

[aaronng]

He wants atw to at the crank...
I'd say, multiply by 1.341 to get hp atw, then divide by your favourite dyno loss %. For me, I divide by 0.75, to give about 228hp at the crank.

[eg9-b16b]

He wants atw to at the crank...
I'd say, multiply by 1.341 to get hp atw, then divide by your favourite dyno loss %. For me, I divide by 0.75, to give about 228hp at the crank.

yup..u're right dude.. I want from atw to at the crank.. anyway thanks for the responses... I'm confussed because sometime they will take favourite dyno loss % is 0.85... which mean figure above (127.8KW atw = 202hp at the crank) for DC5R is not impressive unless the dyno loss % is 0.75... cheers...

[aaronng]

Yeah. the dyno loss can vary a lot. I have dyno'd 119.5kW at one dyno and 110.0kW at another. Assuming I have 145kW, that is 82.4% and 75.8%. Depends where you dyno......

[dsp26]

to add to what aarongg is saying about drivetrain loss.. i think people should read up on this thread:
http://www.ozhonda.com/forum/showthread.php?t=31004

Specifically:

Rule of thumb is that if an engine makes 160kw at the flywheel it will make 160hp ATW (119.38kw) on a Dyno Dynamics dyno but I know most on here like KW readings.
Regards Dyno Dave

so the article is accurate if i'm not reading dave's words wrong?

Alright i'm shakey in mathematics, but

if

%Loss x 160kw = 119.38kw at wheels

this means

the "rule of thumb" % loss = 1- (119.38/160) = 25% (rounding up)

so using this as an example

in other words a stock b16a (which everyone is so obsessed about) in from factory specs shoudl be putting out

118 flyheel figure x 0.75 = 88.5 kw at wheels

in my personal experience this is accurate as i dyno'd 89.9 kw at wheels when my car was stock except for a intake box

[bennjamin]

guys its impossible to accurately tell what a car has @ the flywheel , from its ATW figures. Too many variables (even comparing stock vs another stock car)
We can only guesstimate :)