TORQUE TALK !

I was chatting last night with some mates who also ride, one who is a real analytical, who makes a lot of his own parts for his road racer, dirt squirt and his 4x4, he works as a clay modeller for a car Manufacturer. The other an ex motorcycle mechanic.

Now my mate did explain torque and power to me in engineering terms, but it's a really hard thing to try and explain simply! I'm just about to have a crack at it, but encourage anyone with a simple explanation to throw it in.

The conversation started with us talking about a ride we went on together recently. It was the first ride with me on the 9, and him on his faithful 2005 R1. Micron equipped, mapped and shorter gearing (on one the front).

He claims, that he could not gain any ground on me until his tacho was at 12,000-12,500 rpm!!!!

He is a little shorter than me, but weighs about the same.

This then got us talking about power and torque. Of power curves, and importantly torque curves.

My simple eg of torque and power is this. Torque, is a force that needs to be applied to an object to stop it moving. So something with high torque numbers needs more force to slow it down. Power is Torque times Revolutions!

Hope that's simple enough.

Anyhoo.........A motor which produces high power, must by pure engineering values produce torque, as power is torque times revs remember!...........Still with me here??? Not sure if I am now!!

Back to it.........So, the nine is producing more torque lower in the rev range, and thus more power earlier too, than his R1. His bike, had to be buried into the high numbers before he could gain ground. Thus, his higher power, and most probably torque figures, will only benefit him on a track, where those top 4000rpm can be utlised consistently.

It also led us to talking about the curve of the engines power and torque. All this talking about Torque is confusing hey!!

Then, this afternoon, I rode a new 2006 blade. stock as a rock. under 1000klms on it! It appeared to have this mother fucking monster torque curve!! Nothing like the 9 or the R1. There's globbs of fat torque belting out the back wheel by 3000, and by 4500 the fronts in the air. As comfy as my 9 too I wonder how mental they are to ride fast on the road like that??? they must honk out of turns! The R1 is a pussy cat to ride low in rev range, but the honda is a raspy feckin mad thing from low to mid, then goes mental at the top like all 1000's should. But I reckon you could hook the westgate bridge up to it and it would still pull top gear at 100k's!!!!

ANyway back to talking about torque!!! Whats you're thoughts?

Hmm thinking back to physics classes..

Torque is all about leverage around a point.
ie the longer the lever the more torque and so the more you can do with less power.
Rotational acceleration is defined partly by torque, but can't remember the equation.

Now how this exactly relates to bike engines is where I get confused.
high bore, low stroke gives high torque right?

But it does correlate to less power but high torque = good acceleration, or the illusion of having lots of power everywhere because you are able to do more with the power you have.

On a side note, my talking boony has just gone nuts. He has never ever spoken a word (even during the cricket) and now I can't shut him up!

Torque is something that I don't have -- when other bikies passes me, on the outside, with one hand and/or one wheel

snip..

My simple eg of torque and power is this. Torque, is a force that needs to be applied to an object to stop it moving. So something with high torque numbers needs more force to slow it down. Power is Torque times Revolutions!

Hope that's simple enough.

well yes..but in think reverse of that
think of torque being the force that starts sumfing accelerating
...from standstill
eg..what starts a flywheel rotating?..torque

Anyhoo.........A motor which produces high power, must by pure engineering values produce torque, as power is torque times revs remember!..........

yes...sorta
a low revving engine (think diesel) may in fact produce MORE
power than a high revvin engine...becoz it makes HUGE amounts
of torque
eg bike- 80ft/lb torque x 12000rpm = 140hp
truck - 400ft/lb torque x 2500rpm = 250hp

Back to it.........So, the nine is producing more torque lower in the rev range, and thus more power earlier too, than his R1. His bike, had to be buried into the high numbers before he could gain ground. Thus, his higher power, and most probably torque figures, will only benefit him on a track, where those top 4000rpm can be utlised consistently.

'zactly
refer to my example above

Then, this afternoon, I rode a new 2006 blade. stock as a rock. under 1000klms on it! It appeared to have this mother fucking monster torque curve!! Nothing like the 9 or the R1. There's globbs of fat torque belting out the back wheel by 3000, and by 4500 the fronts in the air. As comfy as my 9 too I wonder how mental they are to ride fast on the road like that??? they must honk out of turns! The R1 is a pussy cat to ride low in rev range, but the honda is a raspy feckin mad thing from low to mid, then goes mental at the top like all 1000's should. But I reckon you could hook the westgate bridge up to it and it would still pull top gear at 100k's!!!!

:

yes...and more so
go ride a ZX12r ..or better a ZX14
you will think exactly the same thing


cheers

Well I thought the 14 was pretty gutless (relatively of course) compared to a sorted 12 BELOW 5K that is... above it it makes more, but the 5K is more to do with the restrictors (14) or timing (12) I think. Busa's prob have a better bottom end (by my ars feel anyway) but not the top end rush of a 12 and the 14 has in spades IMHO. Mind you I tend to turn the throttle a little too hard for my own good

Torque is a twisting force (as stated above) and the analogy of a lever above is prob the best example I have ever heard of describing it. Torque can be "modified" by gearing a bike lower, thereby applying a (relatively) longer lever to the rear wheel (as it where) which means you cant go as fast as their is the bloody big lever tied to the back wheel clomping around every revolution .

9's were always noted for being more bottom and mid, than top compared to say a 12 which was mostly top end which sort of defeats teh prupose of having a big motor , so maybe it is inidvidual fuelling or something more than the whole model range as my mates tuend 9 stayed with the 12 right up to silly speeds (taking capacity into account of course). Putting a big pipe on a bike almost always means you are trading off high HP for losing torque (and HP) off the bottom but good tuning can hide some of that.

Putting a big pipe on a bike almost always means you are trading off high HP for losing torque (and HP) off the bottom but good tuning can hide some of that.

Precisely why im not too keen on putting an aftermarket can on my bike. At 2500rpm its got as much torque as my old gpx had at about 9k (55ish nm), and at 3k it has more than the gpx had at its highest point. Once you hit 4.5k its basically 82-86 nm until 500rpm before redline *tim allen grunt*.

I did gain mid range and top end on the gpx with a new pipe, but i did loose a little tractability at low end. and i like how the rf handles (for now).

Anyhoo.........A motor which produces high power, must by pure engineering values produce torque, as power is torque times revs remember!..........

yes...sorta
a low revving engine (think diesel) may in fact produce MORE
power than a high revvin engine...becoz it makes HUGE amounts
of torque
eg bike- 80ft/lb torque x 12000rpm = 140hp
truck - 400ft/lb torque x 2500rpm = 250hp

:

yes...and more so
go ride a ZX12r ..or better a ZX14
you will think exactly the same thing


cheers[/quote]What do ya mean sorta Smitty? Is there something else you wanted to add to that bit? As you say sorta, then back the point up 100%???/

You may be right with the 12, however the 14, from all reports, is a bit doughy down low??? I havn't ridden one, and certainly havn't seen the torque curve, so they could be wrong, and it may just be variation perception. ie- there is just sooooo much power pouring on from mid revs, it makes the bottom appear lacking in comparison, rather than actually being lacking in pure numbers. But I'd need to see some graphs and numbers to tell.

I actually don't find the 9 as perky off the bottom as my hornet was, and my mates comments from the seat of his R1 surprised me. Certainly intil 5, it's really lazy, but hit 5 and it comes alive. From there till the redline it just keeps on keeping on. I love kwaka sports motors for that reason. It's one of the things I loved about the first big K bike I rode (A real live genuine Z1000 MKIII.scared the pants off me), they just kept on pouring on the power till you either ran out of road, or ran out of ticker.

i once read a few things...

the perfect engine is a gas turbine.
as the torque and horsepower curve is identical. as revs rise, so does torque and horsepower. and an even straight line.

in piston engines, the way to produce power, is to get the horspower up before the Torque runs out.
when the torque runs out, you need to have enough horspower to take over the pull of the torque, otherwise you die in the bot bot.

thats my 2c.
sorry, no refunds available

As they say, torque sells bikes, power wins races.

For the street something with a nice even power curve with a fat torque range is always going to be easier to ride faster. You can't always be in the perfect rev range on the road.

Which is why I think some of the best bikes for blasting in the hills are things like 9s or Z1000s.

What do ya mean sorta Smitty? Is there something else you wanted to add to that bit? As you say sorta, then back the point up 100%???/

You may be right with the 12, however the 14, from all reports, is a bit doughy down low???

Strika
yes..what you said was correct
and what I added ..maybe could have been said better
I was just giving another example of illustrating how power can be
derived...

What do ya mean sorta Smitty? Is there something else you wanted to add to that bit? As you say sorta, then back the point up 100%???/

You may be right with the 12, however the 14, from all reports, is a bit doughy down low???

Strika
yes..what you said was correct
and what I added ..maybe could have been said better
I was just giving another example of illustrating how power can be
derived...

Just to make up for it, I think you should let me ride your 12. Just so I can compare it to the 9 and get a real idea of torque!

But now that we discussed it you have torqued me into a beer

More torque = less need for power and don't need to rev the ass off it
more power = less torque means you need to rev the ass off it to get it to move eg 250.

Is that it

Putting a big pipe on a bike almost always means you are trading off high HP for losing torque (and HP) off the bottom but good tuning can hide some of that.

Precisely why im not too keen on putting an aftermarket can on my bike. At 2500rpm its got as much torque as my old gpx had at about 9k (55ish nm), and at 3k it has more than the gpx had at its highest point. Once you hit 4.5k its basically 82-86 nm until 500rpm before redline *tim allen grunt*.

I did gain mid range and top end on the gpx with a new pipe, but i did loose a little tractability at low end. and i like how the rf handles (for now).

the difference is buying a quality pipe rather than an oversized milo eg Yoshi can and you can have an increase all over the shop including a nice note eg Arata

As they say, torque sells bikes, power wins races.

For the street something with a nice even power curve with a fat torque range is always going to be easier to ride faster. You can't always be in the perfect rev range on the road.

Which is why I think some of the best bikes for blasting in the hills are things like 9s or Z1000s.

erm not quite on the ive got a big dickometer HP sells bikes

agree torque is where its at , exact reason i loved the 916 and enjoy the VFR400 so much

:? But now that we discussed it you have torqued me into a beer

More torque = less need for power and don't need to rev the ass off it
more power = less torque means you need to rev the ass off it to get it to move eg 250.

Is that it

more power doesnt always mean less torque


at the end of the day doesnt matter if you have 500hp if it takes 10 mins to get there

turque = direct function of the force exerted by the motor (or the force required to stop it if you like).
hp is a purely mathmatical term which is sort of useful for comparing peak output, but not really anything else.

as pointed out above, unless you have engines of similar capacity, engine layout, etc, it doesnt mean jack.

I have a toyota corolla, according to this it is 1762cc and makes 115hp (86kw) at the top of the power curve (5600, redlines at 6200).

However my bike has been dyno'd at 118hp peak hp and it is 937cc, does that make it better or worse than my bike because it produces just under twice the power per cc of my car?

Neither, they are totally different animals. At cruising revs ( 2.5-3.5k ) the carolla is producing 82nm of torque, basically the same level of torque that my rf will produce at about 6k all thr way through to 11k. Also if we were to take my old gpx for example, at cruising revs it would make 32nm of torque at 4.5-7k and 55nm from 7-10k.

All of these engines have totally different characteristics. The car can pull along quite nicly from a standstill and get moving along quite nicely while barely hitting 3.5 thou. Also bear in mind that its doing this while pulling around about a thousand kilo's of engine, chassis and any shit i've stacked in the boot.

The gpx needs a bit of clutch slip from the start, but can get moving fairly quickly because it is a high revving motor thats designed to just pull through the revs, getting it to 7ish though gets it off the line nicely.

The RF is a middle of the road motor, it's high revving engine with a couple hundred more cc to its name than the gpx, that combined with nearly a decade of development gives it round about 35-40hp more. It can get along relatively low in the revs with hardly any clutch slip required. As its rather tall geared, getting it up to cruising speed doesn't require much in the way of revs, you dont even need to hit 5krpm in any gear and soon your at federal highway speeds. This is all due to the available torque, doing this will still get you off the line fastest and you've absolutely blown them others away, mind you, it is about 780 kilo's lighter than the car still.

This doesn't mean my car or my new or old bike is better, ,they were all straight 4 cyl engines, they just have their specific purposes in mind, and they do what they do well.

Last edited by mike-s on Fri Sep 15, 2006 6:50 pm, edited 1 time in total.

Mike, Don't forget to include weight in the above calculations!!!!