lets talk about torque

[sean brady scooters]

what is torque...?
and how does it apply to scooter engines...?
lots of folk say that they want a real torquey engine ....so what does that mean exactly..?
most assume that means the most massive CC you can achieve ,low port timings and so low revs....after all theres no substitute for cubes....(or is there...?)
but is this actually true...?

and just to start this off ,do any of you have a dyno print out from say a AF 250 ...?

you would of course think that 250cc would provide you with oodles of torque.....would you not....
so lets concentrate on torque and not bhp....
adaquate torque is after all what makes a scoot driveable and user friendly...,high BHP on the other hand is deemed to make them far too peaky....
but again is this really true ,or just the result from bad tuning....?

[J1MS]

An effective flame front burning at an even controllable rate over a wide rev range, covering about 50 degree of crankshafts rotation after ignition takes place, can this help develop more torque ?

[davidblythe]

horses for courses

have a stage 1 DRZ400 for the dirt true 33bhp 26lb ft of torque at the back wheel, also have had loads of 350 LC,s which have 33bhp as standard dont know the torque figure but is definately lower as it revs higher

DRZ is superb, stand up wheels on the dirt, steams up any wet chalk hill but useless on the open road above 75mph as the torque curve drops away, 350 LC when it hits the power curve at 6500 rpm is a smile a second and can humilate much bigger bikes in the lanes but an LC engine on the dirt would be a pain

torque definately has its place in the right areas but the common excuse for poor power is it has a good torque curve but if its not needed at those revs whats the point

[sean brady scooters]

what i would really like to see here is results from folk having in excess of say max 18/20 ft/lbs of torque from say 225 cc,s....
and a usable range of over 2,500, 3,000 revs....at say 15 plus.

[yam-lam]

what i would really like to see here is results from folk having in excess of say max 18/20 ft/lbs of torque from say 225 cc,s....
and a usable range of over 2,500, 3,000 revs....at say 15 plus.

this is my ts 225 which was built by my mate chris sturgess and tuned by mb, which has quite a high torque , is this any help to you sean


26.3bhp@6909rpm 21ft-lbs@6539rpm

[Fred_64]

This torque issue reminds me one question I have; why do people use exotic conversions with Kawa / Honda / KTM motocross engines rather than Montesa, Beta, Gas Gas = Trial motorbikes, with loooooads of low down torque ?

If you want to go for torque, I would advise you to look for info on Trial engines, their design, port layout and so on...

[shocky]

This torque issue reminds me one question I have; why do people use exotic conversions with Kawa / Honda / KTM motocross engines rather than Montesa, Beta, Gas Gas = Trial motorbikes, with loooooads of low down torque ?

If you want to go for torque, I would advise you to look for info on Trial engines, their design, port layout and so on...

becouse for some its a p1551ing contest with how much BHP you have the same as when people near me say my TS1 240 will do 95+ ........ok then i will "race" you to exeter services and back 2 up with 20kgs on the back i can get there and halfway back on 1 tank of fuel on my standard gts they will stop many times for some strang reason they never take me up on the offer ........
the only problem i can see with a lower revving high torque engine would be heat dissapation power creates heat and revs(higher speed flywheel/fan) helps air flow

[DJB]

like this has 30lbs

[22/2]

So we are all talking about the same thing and to answer your first question (care of wikipedia)

Torque, also called moment or moment of force is the tendancy of a force to rotate an object about an axis, fulcrum or pivot. Just as a force is a push or pull, a torque can be thought of as a 'twist'.
In more basic terms, torque measures how hard something is rotated. For example, imagine a spanner trying to twist a nut or bolt. The amount of 'twist' (torque)depends on how long the spanner is, how hard you push/pull on it and how good you are pushing it in the correct direction.

What we call in Wales ' Grunt', it's not top speed, how many cc's or BHP, its how quick you get there, the force trying to lift your front wheel, pushing your arse down the seat, what makes your pillion grab you around the waiste.

A usable range over 2500 - 3000 revs, this is my Taffspeed RB 250 with a Franspeed JL3

I can be a lazy rider, it pulls from 40 mph in fourth so I don't often change gear.

Rich

[sean brady scooters]

thanks so far folks,for posting up your results
just what i expected .
greater torque is to be had from higher revving machines than say ,large CC lower revving set ups,which most folk assume should be for some strange reason more torquey..