Torque measurements

[pelo]

Possibly silly question: I am used to measuring torque in Nm (Newton Metres). I have been confused about the units used in gran turismo (Kilogram Metres, Kgm). But just the other day i thought: 10 newtons per kilo. 42.9Kgm = 429 Nm ??? is this right?
An d how do foot pounds work?

[AJLintern]

I imagine 1 pound foot of torque would approximate to 1.35 NM

[V8Bert]

That's pretty much correct.

To be precise you have to use 'g' (which is about 9.8 instead of 10) to convert from Kilograms to Netwons.

[pelo]

quote:

To be precise you have to use 'g' (which is about 9.8 instead of 10) to convert from Kilograms to Netwons.

9.8? isnt that accerleration of gravity (m/s). generally accepted as 10?

[V8Bert]

quote:

9.8? isnt that accerleration of gravity (m/s). generally accepted as 10?

Yes.

[AJLintern]

Or 9.81 if you want to be that accurate

[ATG]

[trainspotting]
'g' is generally assumed to be 9.8 ms-2 (or N/kg). It varies depending on your alltitude, the density of the rock you're standing on. The actual force you "feel" also depends on how far you are from the axis of rotation of the earth, the position of the moon. For a fascinating table of values measured at different lattitudes see:- www.earthmatrix.com/extract81.html
[/trainspotting]

[pelo]

[KenD]

As far as I know you cannot convert from Nm to ftlbs as there is no direct conversion factor

[GreenV8S]

quote:
As far as I know you cannot convert from Nm to ftlbs as there is no direct conversion factor

Nonesense, they're both units of torque and can be directly converted just by multiplying by the appropriate factor.

[SGirl]

quote:
As far as I know you cannot convert from Nm to ftlbs as there is no direct conversion factor

Isn't the conversion factor 1 Nm > 0.738 ft. lb.??

[animal]

1.000 Nm : 0.738 lb/ft sounds about right to me.

Can also be expressed as 1.000 lb/ft : 1.355 Nm.

[gnomesmith]

You guys are all torque.

[JohnL]

1 kg = 9.81 N (so 1 kgm = 9.81 Nm as above)
1 ft = 0.3048 m
1 kg = 2.2 lb

soooo ...

1 Nm / 9.81 = 0.102 kgm
0.102 kgm x 2.2 = 0.224 ft-m
0.224 ft-m / 0.3048 = 0.735 lb-ft

so:
1 Nm = 0.735 lb-ft
1 lb-ft = 1.3607 Nm (ie 1/0.735)

[JohnL]

So how do you convert horsepower to Watts (or Kilowatts)?
What is the definition of 1 hp?

[AJLintern]

Depends what type of horse it is I suppose: ie. a shire horse is more powerful than a pony

[Richard92c2]

Horsepower can also be measured in decibel ...

If one screams at the top of ones voice until one is "horse" the measurement can .......

Ok, Ok it is after all Friday! I'm leaving now!

[Fatboy]

1 kW (1000W) is about 1.66 hp IIRC

[ellingtj]

1hp = 1.014Ps = 0.746kW

[GreenV8S]

quote:
1hp = 1.014Ps = 0.746kW

[anorak-mode-on]
Remember you still need to account for the temp/pressure conditions that the measurement was taken at, there are umpteen different 'standard' conditions each with their corresponding correction factors, so you can't even assume that 1hp = 1hp unless they are corrected to the same standard.
[anorak-mode-off]