Re: Horsepower / Torque [ On track difference ]

Approved and merged!

Maybe he meant that the track had more curves than straights and lower to mid end was more important than top end. Just my thought!

Re: What is "Power", what is "Torque"..??

Very Right example put in.

Regarding topic, my understanding is "Power" ( BHP, PS) is pulling power of a engine, applied to flywheel with all components of a engine in place (India only) and
"Torque" (Nm) is how you to reach to that maximum Power, in other words more the torque more easily you can reach the rated max power of motor.


Correct me if i am wrong

Re: Horsepower / Torque [ On track difference ]

so for curvy tracks torque is better than max bhp ?

----consecutive posts auto-merged-----

Still confused : ( ,
I have a duke 200 which is roughly 25 BHP @ 10 K RPM, 19 something NM Torque @ 8K RPM I guess, My friend has a RE 350 Thunderbird which generates roughly 20ish BHP @ 5K RPM and 28NM @ 4K RPM ,

If his RE's torque ends at 28NM @ 4K RPM, what's the use of going 5K and generating 20ish BHP.. and same with my DUKE where BHP continues to increase till 10K ? How it helps ? in acceleration or what ? I am more confused than ever.

Thanks Divya and Abhay, I am just trying understand clearly as I feel stupid not knowing exact difference in my mind considering I love biking . : (

Re: Horsepower / Torque [ On track difference ]

Replies in bold.

Go through these links too.
The Difference Between Torque And Horsepower Explained
Torque vs BHP? - Team-BHP

Re: Horsepower / Torque [ On track difference ]

Thanks Divya, for more elaboration. Also to add to this Duke 200 and Bullet 350 are 2 very different bikes. By very different i mean the way they produce Power/Torque. Power and torque ratings of a engine is mostly dependent on stroke/bore ratio of engine, and the advance technologies user. These two are not Apple to Apple comparison.

If the comparison is to be made do it for a 2 bikes that are of same company (Tech used in bikes).

Re: Horsepower / Torque [ On track difference ]

Torque is the force acting down on the crank. The longer the stroke, the more distance of crank pin from crankshaft centre, and hence more "twisting" force. Power is the rate at which this process is repeated.
Consider a see-saw on one side alone. A child at one end is pushing down at one instant(consider this instant as 1 rpm). The force on the see-saw is increased by increase in see-saw's arm length(crank pin distance from centre). Considering a fixed arm length, Power is the rate at which the child pushes the see-saw again and again. So, more rate(number) of push by the child per second(more rpm)=more power.
Torque can be felt as it is a physical one but power is only expressed(using formula) and cannot be visualized in any form.
In general,
torque=acceleration rate
power=top speed possible.
But the gear ratios and rpm play a major role here. Gears act as torque multipliers. Low Gear=Higher torque figures at wheel(Less Speed) and High gear= Lower torque at wheel(More speed).
But in any gear(as far as I know), the power is the same at the wheels.
So, torque is the "pull" effect felt during acceleration while power determines how long the "pull" effect can be felt and hence the top speed.

Re: Horsepower / Torque [ On track difference ]

Nice explanation brother.
You must be a teacher or an instructor by profession.

Soulfuel

Re: Horsepower / Torque [ On track difference ]

I'm neither a teacher nor an instructor. I'm just a student..

Sent from my ST18i

Re: Horsepower / Torque [ On track difference ]

Although we had got nice explanations about Torque and Power can somebody explain why there is a drop in both(As shown in graph in early posts if this thread) after a particular RPM at which they are rated max.


Thanks in advance

Re: Horsepower / Torque [ On track difference ]

Actually that has to do with the source of the power, i.e., the air fuel mixture being burned. At lower RPMs and RPMs nearer to red-line, the air-fuel mixture is not burned efficiently, hence the drop in power figures.

Re: Horsepower / Torque [ On track difference ]

A particular amount of a/f mixture takes a particular time to burn. This time quantity is constant for a particular engine. Now, at max torque, the fuel is burnt nearly completely. Beyond that rpm, the fuel does not get the necessary time to burn completely. And so, torque reduces as shown in dyno graph. But, there is an increase in rpm and this compensates for loss in torque and thus power rises. But beyond a particular rpm(max power), there is not enough time for fuel to burn and this results in servere reduction in torque. The loss is to high for rpm to compensate. Hence there is reduction in power. For high revving engine, this fuel burning time is increased by providing the spark earlier in the cycle at higher rpm.

Sent from my ST18i

Re: Horsepower / Torque [ On track difference ]

Power is the product of torque multiplied by speed of rotation.
Powerband = range between peak torque and peak power. (A very tiny part of the rev band)

The ideal case should be a flat torque curve throughout the rev range.
But then you have limitations - port efficiency, timing, carburetion, and exhaust limitations etc. You never get a flat torque curve.
The engineers use the intake, exhaust, timing and carburetion systems to eliminate dips in the torque curve, but despite all of that; we get a usable curve which has a peak spot after which it tapers down.

Same goes for power curve, which obviously has a higher point because of the formula mentioned in the 1st line in this post.

One link with less jargon and more content - Technology.

Re: Horsepower / Torque [ On track difference ]

Nice explanation though but still

@ John- as much as i know Fuel burning time has no correlation with RPM, it might have a correlation with power band. RPM is also measured as ft/s for a piston movement. Now here is the catch max safe speed is some 3400(Approx) ft/s which can be different rpm for different engines (Short Stroke, long stroke). that is reason why a Duke is a high revving engine and bullet is not. Max speed achieved till now is 5200 (Approx) ft/s by a honda engine and that too by high tech offcourse.
[MENTION=47074]Divya[/MENTION] - I am a bit convinced with the explanation, but where it is contradicting, as explained above. All efficiencies including air drag can only occur when every cycle is complete, i.e. without any of inefficiency, because post that engine will not be able to provide enough power to increase RPM. So what i am not able to understand is how can engine provide more power when torque is also dependent on RPM basis formula

Torque (lb/ft) = HP x 5252 /RPM

and why torque has a dip till Max power.

Hope my query does not bother.

Re: Horsepower / Torque [ On track difference ]

I would like to read more about it, can you suggest any online info/material in that direction?

Re: Horsepower / Torque [ On track difference ]


Google Baba ki Jai

But word of caution, not every thing is practically right, and you need to figure out yourself. Also try with different keywords. Am also naive to it and learnt by comparing actual mechanical of my TBTS 500