One For Lawsy

[Flukey]

OK you experts,

How many NM's do I have at the wheels and what is the formula for calculating it please?

[bugster70]

Nice little increase you have yourself there Luke, congrats mate!

So, what's it like to drive now?!

[-carty]

think of a number, add 2, times it by 8, then double it, take away 5, divided by 10...

your number is 2... :hsdance:

[IH8TOADS]

This should interest you. some calculations.

[ENVY-T]

No mate, just use the gooses formula, you have 950nm!

[IH8TOADS]

dat alot of twisn powa. Not that I know but that seems like a big increase in torque compared to kws. that's >50% nm increase. I like!!!!

[Flukey]

  IH8PORK said:

dat alot of twisn powa. Not that I know but that seems like a big increase in torque compared to kws. that's >50% nm increase. I like!!!!

You can feel it, but I want to know more precisely what I have.

Anyone seen Lawsy????

[IH8TOADS]

Ok here goes.

THERE IS A GOOD CHANCE THAT THIS IS WRONG SO PLEASE FEEL FREE TO ABUSE ME!!!!!

If Horsepower = (torque x RPM) / 5252.......then...

Torque (lb/ft)= (horsepower x 5252) / RPM

245rwkw = ~328rwhp

so torque in foot pounds = 1725282 / rpm (from which max hp was read)

To get to Nm devide your torque answer by 0.74

Therefore if your peak power was at 5250rpm (example only) you should make 443rwnm

[Lawsy]

  IH8PORK said:

dat alot of twisn powa. Not that I know but that seems like a big increase in torque compared to kws. that's >50% nm increase. I like!!!!

You'll notice that whatevet the percentage increase in torque is, at any given rpm point, that that same percentage increase applies to the power as well..

Ok, so it has tractive effort stated, and just after 120km/h the TE curve flattens, this is most likely about 500 rpm after max torque...

But it doesn't really matter because tractive effort doesn't need an rpm value to convert anyway.

Lets take 6500 as your true max tractive effort, about 10km/h before the curve flattens.

Torque = (rolling radius x Tractive effort) / total reduction x 1000

T = (300mm x 6500N) / 3730

T = 523nm at the rear wheels. Which is a damn good effort.

I take rolling radius as this.

You have 245/40/18's, total diameter is 25.5 inches. Minus an inch for tyres with a profile of 40 or more, running between 35- 45psi in the tyres. For working it out with lower profile tyres, take less than an inch. Say, 1 - 2 cm depending on just how low the profile and how much pressure is in the tyres. If you are on the dyno, simply measure it! Get a square, stick it ontop of the tyre and measure from the square to the ground. Easy!

So 300mm is a nice, non fudged round number to use for this calculation...

So that's it, you have nearly 530 tooheys news pushing your car allong....

[Lawsy]

  IH8PORK said:

Ok here goes.

THERE IS A GOOD CHANCE THAT THIS IS WRONG SO PLEASE FEEL FREE TO ABUSE ME!!!!!

If Horsepower = (torque x RPM) / 5252.......then...

Torque (lb/ft)= (horsepower x 5252) / RPM

245rwkw = ~328rwhp

so torque in foot pounds = 1725282 / rpm (from which max hp was read)

To get to Nm devide your torque answer by 0.74

Therefore if your peak power was at 5250rpm (example only) you should make 443rwnm

The metric version is this

kw=T x RPM / 9549.

He makes 245kw @ 5200rpm then;

(245 x 9549) / 5200) = 445.62. It Removes all the rounding errors with the SI conversions.

But max torque is never at max power Hope that helps.