Safe Speed Forums

I'm pretty sure it's right, and it is one hell of an engine, although maybe not quite so much by more modern standards.

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Paul Smith
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FWIW in the grand scheme of things, 5000Nm of torque isn't actually that much. I'll look in my reference books on Monday (I can't remember the calculations off the top of my head) and work out the minimum size required to transmit that.

We build hydraulic drilling and anchor driving heads at work that deliver upwards of 60,000Nm

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Science won over religion when they started installing lightning rods on churches.

an m5 produces 520Nm at the engine.

As far as previous comments about 300Nm requiring a decent engine - a 2L diesel engine or 3L petrol engine will give you more than that.

Pauls figures are right.

A turbocharged 4WD Mitsubishi Lancer ( I drive a Gp A rally version ) produces about 390Nm at peak torque and 290 bhp ( 215kW) at peak power. With a drivetrain ratio of 12.6:1 in 1st total torque is 4.8kN. Sharing this with 4 forged driveshafts of a minimum 25mm OD, peak torque correponds to a surface stress of about 25% of breaking torque. Problems occur on hairpins when CVs and the mass:resilience of the vehicle through 3 plated limited slip differentials can put an oscillating load onto a peak load to the outside front wheel that can break the drive shaft.

Sixy_the_red: we make power / torque measurement equipment for diesel 2 stroke engines of 108,000 bhp. Thats 7,760,000Nm at 92 rev/min ( for container ships !)

How do you work out torque on a shaft weight of 7500 kilograms, being turned at 3000 rpm? What else do I need to know?

It's a generator producing 11000 volts at 1408.2 amps
I presume it takes some effort to get it up to speed, and I'm wondering if the stream at the bottom of our road is up to it?

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Time to take responsibility for our actions.. and don't be afraid of speaking out!

5000nm is alot of twist for a car... my company vehicle has half shafts as thick as my arms and it's only a tiddler, they do have to transmit lots of twist, hold up lots of weight while doing so and do so at varying track widths.

Not sure my car could muster 5000nm, no I am sure, it can't...

520?!!!!!!!

Whilst I freely admit to not knowing much about beamers, I'd have thought it would be nearer 350Nm! My old shed is 3 litres (petrol) and only manages 255Nm - and it was regarded as being pretty good in its day!

You'd need to know what the shaft was driving. The weight of the shaft (7.5 tonnes?!) won't make that much difference once it's up to speed.

If you're generating 11,000 volts and 1408.2 amps, the power is about 15 MegaWatts! That's one hell of a Christmas tree you've got there Ernest!

15,000,000 Watts at 3000 RPM will give you a rough idea of torque. You need to convert the speed in RPM to Radians per second. If memory serves, you multiply by 2 x pi so the speed is 18850 Rads per min. or 315 Rads per sec.

Power = Torque x Angular speed

so 15,000,000 = Torque x 315

Torque is therefore about 47,620 Nm or 35,250 lbft in "old money"!

Hmmm. I'm beginning to see why the shaft weighs 7.5 tonnes!

I've a feeling you'll need quite a big water wheel on the end of it!

this might scare you then:

VW Toe Rag:

Direct quote from the E60 M5 specification sheet:

Power: 373 kW, 500 HP SAE @ 7,750 rpm; 383 ft lb , 520 Nm @ 6,100 rpm

and I am thinking of purchasing a modified version (supercharged) developing "APPROX 380KW AT THE WHEELS AND APPROX 760NM OF TORQUE" according to the dyno run. That's over 500hp at the rear wheels which would be over 600hp at the engine and that's from a 2000 model E39 M5.

In case anyone is wondering WTF I need that much power for, well I have to drive 2 miles to get to work

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Ross

Yes I'm a hoon, but only on the track!!!!

I don't think there's a smiley to say much to that appart from maybe !

Adam - the reason for the size of the shaft is more to do with resistance to twisting and fatigue resistance than the ability to transmit the torque. You might also find that its something to do with harmonic vibration.

Every rotating shaft will go into a standing wave at a particular speed. If the harmonic speed corresponds to the working speed it will end in catastrophic failure of either the shaft, or more likely one of the bearings supporting the shaft.

There's alot more to it than simply the ability to withstand the torque applied.

Ernest. As Mole said, once the shaft's turning it won't produce any torque. Its more a question of how much torque it will require to get it turning in the first place.

Good grief this thread is reminding me of things I thought I'd forgotten! Maybe 3 years at Uni wasn't a complete waste afterall!

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Science won over religion when they started installing lightning rods on churches.

That's pretty obscene!

I know the current big diesels can manage staggering amounts of torque but that's something else again!

I think Paul was only talking about the humble E34 though - whch I gather is more the small shopping hatchback of the "M" series world!