how much torque ?????

[no chicken tonight]

can someone please tell me why it is all but impossible to get this info from dealers of all brands of outboards.
the amount of torque an engine puts out is a better measure of an engines performace than just max horse power, yet i cant seem to get this info anywhere.
any car/4wd/truck brochure clearly states Nm of torque at whatever revs and Kw at whatever revs.
correct me if im wrong, but i think this is very important, as the same hp outboards of differing brands can vary greatly in performance, particularly hole shot and this has everything to do with torque.

[FNQCairns]

Because I think each manufacturer has something or multiples of something to hide within it's lineup, especially on outboard application where torque is always king this doesn't make for good marketing.

cheers fnq

[Spaniard_King]

Michael.. I will dig up some stuff for ya :)

still sick of trippin over that 2hp::)

[WalFish]

Gaz,
I too would be interested to read anything that you could dig up. Torque figures are the reason Falcons always tow better than Commodores, and is the figure most people look at when looking at buying a car or 4WD for boat hauling. Very difficult to come by for outboards though.

It is one of the thoughts that entered my mind when choosing an outboard for my boat. I eventually went the Honda 135, which is a detuned 150, thinking that the larger capacity would give better torque?? Happy to hear thoughts on this also.

[Wahoo]

found this on THT last year sometime

250 Verado - 656 NM (482 ft-lbs) at 4000 RPM through a 1.85:1 gear ratio = 892 ft-lbs max at the prop shaft at 4000 RPM
250 E-TEC - 575 NM (423 ft-lbs) at 3091 RPM through a 1.85:1 gear ratio = 782 ft-lbs max at the prop shaft at 3091 RPM
250 Suzuki - 313 NM (230 ft-lbs) at 4500 RPM through a 2.29:1 gear ratio = 526 ft-lbs max at the prop shaft at 4500 RPM
250 Yamaha - 303 NM (223 ft-lbs) at 4000 RPM through a 2.00:1 gear ratio = 446 ft-lbs max at the prop shaft at 4000 RPM

225 Verado - 635 NM (468 ft-lbs) at 3500 RPM through a 1.85:1 gear ratio = 865 ft-lbs max at the prop shaft at 3500 RPM
225 E-TEC - 518 NM (381 ft-lbs) at 3091 RPM through a 1.85:1 gear ratio = 706 ft-lbs max at the prop shaft at 3091 RPM
225 Suzuki - 312 NM (230 ft-lbs) at 3500 RPM through a 2.29:1 gear rato = 526 ft-lbs max at the prop shaft at 3500 RPM
225 Honda - 295 NM (217 ft-lbs) at 4000 RPM through a 1.86:1 gear ratio = 403 ft-lbs max at the prop shaft at 4000 RPM
225 Yamaha - 294 NM (217 ft-lbs) at 4500 RPM through a 2.00:1 gear ratio - 434 ft-lbs max at the prop shaft at 4500 RPM

[firstlight]

Thanks for that Wahoo, possibly the best layed out comparison I've seen yet.

Makes you wonder if manufactures are truthful about HP with such varying differences in torque.

Sorry mate, is it a typo or are the 225 & 250 Zuk's prop shaft torque the same.

cheers
firstlight

[firstlight]

So Daz, is the new boat getting a Verado ?? ...Lol...

[ozscott]

Torque in vehicles, especially towing, and especially those with limited gears is very important. I think the ability to rold revs without touching the throttle much (or at all) meeting waves but still keeping the same speed is an example of torque on the water - I would have the best power AND torque available if I could. But I wonder how much difference it makes on the water in the real world because so many engines are tested and often tested on the same type or make or boat and none of the testers are getting wowed by the torque difference - or the product of that - between them...

Cheers

PS. On the above analysis the Yammy getting half the torque of the Verado at much higher revs should translate to a much less drivable and inferior engine (on the road it would have to) but on the water...well...cant see anyone jumping from a 225 Yammy (or Honda) and getting a 225 Verado on the back and thinking that the Verado is twice as good (Timiboy might disagree!).

[Feral]

Hard to say, could be that they haven't thought to doctor up the Torque readings yet, so dont want to publish them, or it could be it doesn't really matter on a boat. I mean up the revs, the prop spins more, whether or not the boat comes out of the hole is another thing!

[Monza]

Torque is simply a factor of the kW and the RPM. If you have a power vs RPM curve (which many manufacturers do give out), you can convert the curve to engine Torque (in Nm) by dividing the Power (in Watts) by the RPM (in radians, not RPM). You will find engines that do not achieve high horsepower early in the RPM curve have poor torque.

Power = kW x 1000
Radians = RPM / 60 x (2 x Pi) (where Pi = 3.141592654)

[Sorry - its the engineer coming out in me]

[ozbee]

remember prop dia may not be the same even though the pitch maybe which can throw another spanner in the works

[ozbee]

unless on a dynamo

[Jabba_]

Torque in vehicles, especially towing, and especially those with limited gears is very important. I think the ability to rold revs without touching the throttle much (or at all) meeting waves but still keeping the same speed is an example of torque on the water - I would have the best power AND torque available if I could. But I wonder how much difference it makes on the water in the real world because so many engines are tested and often tested on the same type or make or boat and none of the testers are getting wowed by the torque difference - or the product of that - between them...

Cheers

PS. On the above analysis the Yammy getting half the torque of the Verado at much higher revs should translate to a much less drivable and inferior engine (on the road it would have to) but on the water...well...cant see anyone jumping from a 225 Yammy (or Honda) and getting a 225 Verado on the back and thinking that the Verado is twice as good (Timiboy might disagree!).

Scott, not until you have driven a boat with a Veradro could you appreciate the how much more grunt they have over a standard 4st, even the DI 2st lack the grunt that the Verardo has..... Out off the hole and mid range acceleration is like no other 4st that I have been in, they literally leave them for dead.. It's just a pity there so heavy

[ozscott]

Fair enough mate. I stand corrected.

Cheers