GL1800Riders Forums banner

1 - 20 of 29 Posts

·
Banned
Joined
·
1,766 Posts
Discussion Starter #1
I am curious as to just what are the horsepower and torque figures for the GL1800. I am pretty sure that both are plenty good enough for most of us, but I would like to know the figures. Anyone got a good idea as to the numbers?
 

·
Registered
Joined
·
3,551 Posts

·
Registered
Joined
·
427 Posts
Can some knowledgeable engineer clarify the relationship of horsepower and torque? If torque makes the bike go, then what does horsepower do?
 

·
Registered
Joined
·
1,084 Posts
horse power

Can some knowledgeable engineer clarify the relationship of horsepower and torque? If torque makes the bike go, then what does horsepower do?
HP is how fast the bike will go.

Ie: timed torque.
 

·
Registered
Joined
·
4,841 Posts
The magic of the GL1800 engine is that it is big and makes a lot of torque without having to spin fast, so it also lasts a long time. For useful power, you want a torque curve that jumps up off idle, goes high and stays flat as long as possible...like this one. Very few motorcycle engines will make 90 ft lbs...the GL1800 makes it from 1500-5500 RPM's. Notice also that the horsepower builds in a perfect straight line to 5500, making throttle response very predictable.

There's not much point in reving it past 5,500, since everyting is dropping after that.

They could have made it spin faster and breath better and it could make a lot more horsepower, but it would have to give up low end torque and durability. But, at what RPM do you spend most of your time on a touring bike?

(There is no replacement for displacement.)
 

Attachments

·
Registered
Joined
·
4,747 Posts
I asked that question to a very well known sprint car engine builder alot of years ago. Here's what he said.....


HP = Muhammad Ali rabbit punch
TQ = George Forman punch hitting then following through all the way to the floor.
 
G

·
I worked for Bill Lear on the Steam Cars and this question would always come up......"what's the difference between torque and horsepower and why are the both listed?" Here's an article that provides good information without getting into all the numbers in minutia.

http://www.carcraft.com/techarticles/horsepower_vs_torque/index.html

The Goldwing has bodacious torque from 1500 to 5500 RPM (as stated in another post) that's what makes it such a great bike to ride.
 

·
GL1800 Doctor
Joined
·
20,546 Posts
Thanks for the link. That's a good read. Interesting that he pointed out the torque and HP curves will usually cross at or near 5250 rpm. If you look at the dyno chart above, they cross right there in the RPM range. I learn something new everyday. :thumbup:
 

·
Registered
Joined
·
4,841 Posts
Thanks for the link. That's a good read. Interesting that he pointed out the torque and HP curves will usually cross at or near 5250 rpm. If you look at the dyno chart above, they cross right there in the RPM range. I learn something new everyday. :thumbup:
Since HP = {(Torque x RPM) / 5252}, the curves always cross at exactly 5252 RPM. Horesepower is the rate at which torque is delivered.
 

·
Grumpy Fart
Joined
·
5,109 Posts
The magic of the GL1800 engine is that it is big and makes a lot of torque without having to spin fast, so it also lasts a long time. For useful power, you want a torque curve that jumps up off idle, goes high and stays flat as long as possible...like this one. Very few motorcycle engines will make 90 ft lbs...the GL1800 makes it from 1500-5500 RPM's. Notice also that the horsepower builds in a perfect straight line to 5500, making throttle response very predictable.

There's not much point in reving it past 5,500, since everyting is dropping after that.

They could have made it spin faster and breath better and it could make a lot more horsepower, but it would have to give up low end torque and durability. But, at what RPM do you spend most of your time on a touring bike?

(There is no replacement for displacement.)
Here's the BMW K1600 chart. Note that 70% of peak torque is available at 1500 rpms.
 

·
Registered
Joined
·
9,391 Posts
All I know is that everytime I twist the throttle, I can't help but get a boner. :thumbup: :lol:
 

·
Registered
Joined
·
7,616 Posts
Graphic, but very effective description of the effect of great power curves.
Or other great curves.

Just last night I rode past a horse and rider and remarked that there's nothing like 1 horsepower for entertainment. He thought it pretty funny.
 

·
Registered
Joined
·
369 Posts
yup trialsman i had a V-MAX that did the same thing for me every time it went into V-BOOST.loved it oooyea. maxster :evil:
 

·
Registered
Joined
·
1,873 Posts
Can some knowledgeable engineer clarify the relationship of horsepower and torque? If torque makes the bike go, then what does horsepower do?
When an engine is tested on a test stand, it is connected to a device that acts as a brake by putting a load on the engine. The engine turns this load which is measured in torque. The work absorbed by the brake is converted to heat. Lots and lots of heat.

Torque is a twisting force with the units of FORCE X DISTANCE.

Also measured is engine shaft speed.

These two numbers, the torque in its units (ft*lbs) is multiplied by the shaft speed in RPM. This product is divided by 5250 and results in the term "horsepower."

So why do all this? Why not just publish the raw torque number?

Because it is easier to understand how much work the engine can do when the output is expressed in HP.

How much work work can be performed with 300 ft*lbs of torque at 5,000 rpm? Not an easy figure to grasp. Or 500 ft*lbs at 3,000 rpm.

But express it in horsepower (285HP), one can instantly understand how much work the engine can do.
 
1 - 20 of 29 Posts
Top