Torque

[Anonymous]

Alas I tried this post just before the "Great Crash of the 16th." and it was unfortuneatly lost in the rubble. So here it goes again.

A while ago I put up a post on horsepower, my GS650GL was dynoed at 60hp. I don't know how much torque it puts out though. Any ideas out there for my 650 and any other models too.

[Hap Call]

Re: Torque

Alas I tried this post just before the "Great Crash of the 16th." and it was unfortuneatly lost in the rubble. So here it goes again.

A while ago I put up a post on horsepower, my GS650GL was dynoed at 60hp. I don't know how much torque it puts out though. Any ideas out there for my 650 and any other models too.

What RPM was the HP recorded at? You can get a snapshoot of the torque at that RPM but that does not necessarily mean that that is also the peak torque.

Torque=(HP)(5250)/RPM

Hap

[Anonymous]

If the shop used a Dynojet Dyno it will chart horsepower at various rear wheel speeds. To determine torque you must know what the horspower is at a particular RPM. The Dyno operator should be able to do this by attaching a lead to one of the spark plug wires while testing. He may also be able to analyse your exhaust emissions and give you some idea if your jetting is correct.
Axel

[kz]

GS 650 (GLX, GLZ, GLD) Spec.

54 KW (73 HP) at 9400 rpm, where are British HP as well = 746 W instead of "normal" HP = 736 W, I don't know which unit you use in the States, OK it's not the big difference...

Torque 5,88 kpm (57,2 Nm) at 8000 rpm

If this is correct it means you loose 21% in your complete drive chain, that sounds a little bit to high to me.

I don't know how much the shaftie steals and if the figures correspond to your particular bike.

But just by calculating backwards from the spec. and your drive chain losses the torque at 8000 rpm should end up at 5.88 kpm * 0.79 = 4.65 kpm/33.6 foot-pounds.

Please give some inputs if you think (or not) you can calculate this way and what or opinion about drive chain losses are.

[Anonymous]

The figure for chain drive loss sounds way high. If I remember right the last time I saw a figure it was about 10%. I think the shafts are about 20%. My .02, worth just what it costs Bob

[Anonymous]

KZ, thanks for the math. Mine is a shaftie and I think that 33 - 35 ft/lds sounds about right. So Cabinovers remarks on the percentages for chain and shaft also fit in. Thanks guys.

When the bike was dynoed I wasn't at the shop, so I have no idea how they did it. They just let me know when I picked the bike up. They did it for their own interest. Not that the figures mean too much, it goes plenty fast enough for me. Just curious.