convert nm/mm to lbs

[lind4hl]

How do you convert this?

im looking to buy springs in UK and i want a 150-175nm/mm spring..

[S-Express]

try here:

http://www.efunda.com/home.cfm

[Keeper of The Kitten]

I'm assuming Newtons per mm (N/mm) rather than Nm/mm?

Newtons relate to acceleration due to gravity which is 9.81 metres per second squared, which makes a Newton around 1/9.81 expressed as kg (so a little over a tenth of a kilo).

In other words there are 9.81 Newtons per kg.

There are 25.4mm per inch.

So for a 150N/mm spring:

150 x 25.4 = 3810 Newtons per inch.

3810 Newtons / 9.81 = 388.4

So 150N/mm = 388.4 lb/in (WRONG!!! SEE BELOW)

For 175N/mm:

175 x 25.4 = 4445 Newtons per inch.

4445 Newton / 9.81 = 453.1

So 175N/mm = 453.1 lb/in (WRONG!!! SEE BELOW)

EDIT!!!!!!!!!!!!!! I've quoted Kg per inch!!!!!!!!!!!!!!!!!!!

Both values are x 2.2

So 388.4 x 2.2 = 854.48

and 453.1 x 2.2 = 996.82

Shucks I really must check things before I commit to writing them....

[lind4hl]

hmm, i

900lbs i got out after some searching, 900lbs x 0,175N/mm = 157,5n/mm

[S2central.net]

900lb springs - Are you building a tank, or the worlds first completely rigid S2 chassis ?

[Big Lee M]

900lb springs - Are you building a tank, or the worlds first completely rigid S2 chassis ?

Have you not seen his build thread BTCC don't even use springs at that rate

[lind4hl]

LOL, a very good suspension man in sweden has calculated on this,
1100LBS @ rear

[S2central.net]

For what application ? Seems a bit extreme to me - I thought 600lb was plenty stiff for an S2 on the race track. But hey...

[lind4hl]

For application: Track!

many beemers that are lightened running 120nm/mm rear, my much heavier car will be around 175-200nm rear and 125-150nm front

these cars are going fast on the track also...

[S2central.net]

But you do know the rear isn't THAT much lighter than the front ?

Weighed one recently - front and rear ?

[lind4hl]

mine is fully stripped out interior, that adds some..

Edit: not weight one recently

i could also add that this is just guide-line springs, i will calculate more on this when the car is completely finished and i have cornerweighted the beast..

[S2central.net]

Certainly an interesting one - what coilovers are you thinking of to accompany this radical beasty ?

[lind4hl]

up front there will be regular bilsteins (yes yes, i know totally wrong valving for such springs) but that is the best i can afford atm until i win on lottery and can buy custom struts with custom shocks.

for the rear there will be custom shocks valved after my spec/lenghtetc, 2-way adjusteble with gas-cannister. probably from Nitron in uk.

[Puglife]

900lbs will be way too stiff for the rear, i'd expect wheel lift and bouncing with those rates for springs... dampers will have to be something special too.

[lind4hl]

As said there are guideline springs until i have cornerweighted the car, and the springs are being valved for this application,

Wheel lift? we´ll se!