Is BHP and Torque really impt , which should we look at ?

[Theoldjaffa]

  On 2/18/2018 at 3:36 AM, Lotr8445r said:

Any idea for which petrol car has the highest torque for cat A? Ty

Those entry level contis.. like S60 T2 or Peugeot 3008.

[Zze121]

Interesting things is sgcarmkt dun allow to filter base on torque.

[DACH]

Understand more about torque and bhp.

 

https://www.howacarworks.com/technology/torque-and-bhp-explained

 

Most people have some idea of what an engine's power is, but are hazy about exactly what the torque figure represents. In fact, many cars that feel powerful are showing the effects of strong torque rather than high power output.

An engine which produces a lot of torque over a wide range of engine speeds will be relaxing to drive because fewer gearchanges are needed: the engine's torque is often sufficient to accelerate the car without changing down. At cruising speeds a lorquey' engine will not need to be turning over very quickly because it can pull at high gearing, which makes for good economy.

Engines that produce a lot of power for their size do not usually produce so much torque, and what torque there is is often produced at higher engine speeds. It is also likely that the engine will be producing usable torque and power over a smaller range of engine speeds; this narrow 'powerband' makes the engine less suitable than a torquey or 'lazy' engine for jobs such as towing, and the car will be less relaxing to drive.

Typical figures

A fairly typical small family car engine puts out, say, 60bhp (brake horse power) at 5000rpm. The same engine can be tuned or modified so that it gives 80bhp at 6000rpm. But although the power is greater, the peak torque can actually be less, as well as occurring at a higher engine speed. There will be less torque at low and medium engine speeds.

In other words, though a car with the tuned engine would have a higher maximum speed, it would only accelerate better as long as the gearbox was used to the full to keep the engine speed up, assuming the gearing remained the same.

In practice, the highly tuned car would almost certainly need to be differently geared to remain drivable - the gears would have to be more closely spaced and the overall ratio slightly lower.

Measuring power

The usual engine test procedure is to run the unit on a 'brake' ordynamometer which measures torque over a large range of speeds by seeing how much braking effort is needed to keep the engine at a steady speed on full throttle.

The torque times the engine speed then gives the power output, called brake horse power (bhp). Power measured like this, with the engine on a test bed, is expressed as a power output at the flywheel.

It is possible to run the car on a `rolling road' dynamometer to measure the power output at the driving wheels instead. This is less than the power at the flywheel because of frictional losses in the car's transmission system, but it gives a more realistic idea of how the car will perform as it shows how much power reaches the road.

Torque/bhp balance

Every engine designer has to bear in mind the balance between power and torque. He might even move the balance a little away from power and towards torque if enough drivers understood the importance of torque and the generalization that power versus aerodynamic drag determines maximum speed, but torque versus weight determines acceleration.

As the car speeds up, forces other than weight, such as aerodynamic drag, rolling resistance of the tyres, and thefriction within the engine and transmission, act on it to try to resist this acceleration. At a certain speed, these drag forces equal the car's driving force, or torque, and there is no excess power left for further acceleration.

Gearing

Changes in gearing are important when looking at power and torque, because the gears act as torque multipliers.

If first gear has a ratio of 3:1, it multiplies the engine's torque output by three when passing it on to the final drive. Similarly, the final drive ratio, typically around 3.5:1, multiplies the torque from the gearbox by that much again.

In first gear, therefore, the torque delivered to the driving wheels can be around ten times greater than the engine's torque output, while speed of rotation will have reduced by a similar factor. This gearing down is necessary because one of a piston engine's biggest drawbacks is its poor torque at low speed.

Torque and brake horsepower curves

The amount of power an engine develops can be measured on a dynamometer and the results plotted on a graph. Shown here are typical curves for an engine in what an engine tuner would call 'road tune' and 'fast road tune' states.

Road tune (near right) is the compromise between power/torque and fuel economy that a car manufacturer builds into a typical car engine when designing it.

A fast road tune engine (far right) sacrifices some fuel economy for increased power. The amount of torque is overall slightly less, and the maximum torque occurs at higher revs. Such an engine develops more top-end power which would give a higher top speed, but its decreased overall torque requires higher revs for the same power output and more gearchanging — a less 'lazy' drive.

Above fast road, it is possible to tune the engine to increasingly higher levels known as 'road/rally', 'rally' and 'race'. But the greater power output is paid for, apart from decreasing fuel economy, by the torque band moving to higher revs and becoming narrower—the car increasingly loses its flexibility.

[Wt_know]

hearsay, this can solve all bhp and torque question ... lol

Edited February 18, 2018 by Wt_know

[Volvobrick]

Most drivers (I would say 80 percent at least) never rev their engine beyond 2500 rpm or step on more than 50 percent throttle. When they buy a car they should just ignore any engine performance beyond half throttle, and 3000 rpm. In other words they should go diesel!

[Theoldjaffa]

  On 2/18/2018 at 5:48 AM, Volvobrick said:

Most drivers (I would say 80 percent at least) never rev their engine beyond 2500 rpm or step on more than 50 percent throttle. When they buy a car they should just ignore any engine performance beyond half throttle, and 3000 rpm. In other words they should go diesel!

Ya! Especially those who are fastidious about FC.

 

They say revving to high rpms will damage the engine.

 

I'm so LOL when I read their comments.

  On 2/18/2018 at 5:47 AM, Wt_know said:

hearsay, this can solve all bhp and torque question ... lol

I thought you'd say SURBO.

 

 

[Ake109]

  On 2/18/2018 at 12:50 AM, Spring said:

Good pointers brought up by most of the bros here like what rpm torque comes in, power to weight ratio etc. My layman opinion is that torque is more important than hp in our day to day driving bearing in mind those pointers from the bros here.

 

Torque at low rpm enables u to take off quick from standstill n more importantly, the confidence to change lanes, overtake etc so in short, give me torque anytime!

 

It is a fallacy that torque is more important than hp.

 

At any given rpm, the torque and hp has a fixed linear relationship.

 

If you can have high hp at X rpm, it automatically means you have high torque at that same X rpm.

 

Just looking at hp curve you calculate torque curve or vice versa.

 

Getting back to torque vs hp.

 

You can have very high torque but near zero hp and your car wont move fast. (no engine is like that but I am just showing why HP is more impt than torque in theory)

 

If you have very high hp but near zero torque (for argument sake, some new engine type that gives you 1NM only but spins at over a million rpm), your car can still be _geared_ to accelerate damn fast because 1NM x million rpm = HIGH HP.

 

​BOTTOM line, HP is more important than torque because you can gear high hp to make whatever torque at the wheels you want. But with low HP, how you gear also no use.

Edited February 18, 2018 by Ake109

[Contipro]

  On 2/18/2018 at 5:48 AM, Volvobrick said:

Most drivers (I would say 80 percent at least) never rev their engine beyond 2500 rpm or step on more than 50 percent throttle. When they buy a car they should just ignore any engine performance beyond half throttle, and 3000 rpm. In other words they should go diesel!

I believe nowadays turbo petrol can produce good range of low end torque.

Or hybrid which can produce immediate torque from motor at low end speed as well.

[Wt_know]

look at the 2.0L turbo diesel. 160bhp pump out close to 400Nm of torque. in spore that’s sibei awesome for low end sprint. only lao kui when pedal-to-metal in nshw

Edited February 18, 2018 by Wt_know

[Charmaine12]

so is 120bhp and 200 torque sufficient for street drive and nshw?

[Wt_know]

  On 2/18/2018 at 12:24 PM, Charmaine12 said:

so is 120bhp and 200 torque sufficient for street drive and nshw?

certainly enough la

do you do 0-100 below 5 seconds?

do you cheong 200kmph in nshw?

if msian myvii can travel whole msia back for cny .. what car cannot?

any car can bring you from A to B in any bhp/nm

if $$$ is not a problem ... of course no 500bhp no talk lor

Edited February 18, 2018 by Wt_know

[Spring]

  On 2/18/2018 at 11:06 AM, Ake109 said:

It is a fallacy that torque is more important than hp.

 

At any given rpm, the torque and hp has a fixed linear relationship.

 

If you can have high hp at X rpm, it automatically means you have high torque at that same X rpm.

 

Just looking at hp curve you calculate torque curve or vice versa.

 

Getting back to torque vs hp.

 

You can have very high torque but near zero hp and your car wont move fast. (no engine is like that but I am just showing why HP is more impt than torque in theory)

 

If you have very high hp but near zero torque (for argument sake, some new engine type that gives you 1NM only but spins at over a million rpm), your car can still be _geared_ to accelerate damn fast because 1NM x million rpm = HIGH HP.

 

​BOTTOM line, HP is more important than torque because you can gear high hp to make whatever torque at the wheels you want. But with low HP, how you gear also no use.

Well my previous Civic FD 1.6l at 125hp doesn’t pick up anywhere near my 216GT at 116hp though admittedly the latter is a diesel turbo but the layman in me feels it’s the torque differential of 151nm vs 270nm that makes the difference.

 

And my conclusion is based on normal day to day driving involving taking off from standstill, overtaking n changing lanes which are staple fare for most of us.

[Wt_know]

270Nm should move a 216GT swiftly

unless it’s full loaded with 7pax

Edited February 18, 2018 by Wt_know

[Jamesc]

High torque is great as it gives you a shove in the back as you accelerate.

 

High speed has no feeling at all.

 

I was in a bullet train and when its cruising there is no feeling of speed.

 

Same as a plane going 800 km/h there is no feeling of speed at all.

 

 

[Volvobrick]

  On 2/18/2018 at 12:24 PM, Charmaine12 said:

so is 120bhp and 200 torque sufficient for street drive and nshw?

 

Nope - need at least 2-3 times more!

 

[Lok666]

  On 2/18/2018 at 12:24 PM, Charmaine12 said:

so is 120bhp and 200 torque sufficient for street drive and nshw?

 

I frequently went on NSHW last time in my old Honda Jazz 1.3L with 100 bhp and 127 Nm with no issues. Just need to time overtaking properly and be conscious not to hog first lane. There are always going to be cars who are faster than you so more importantly, just enjoy driving the car that gives you the best feel. 

[flashbang]

  On 2/18/2018 at 5:48 AM, Volvobrick said:

Most drivers (I would say 80 percent at least) never rev their engine beyond 2500 rpm or step on more than 50 percent throttle. When they buy a car they should just ignore any engine performance beyond half throttle, and 3000 rpm. In other words they should go diesel!

We haven't even mentioned those drivers who love travelling 30 on a 60 road, or 60 on the highway at lane 2. These drivers should save money and buy a 1L car.

[Ake109]

  On 2/18/2018 at 12:41 PM, Spring said:

Well my previous Civic FD 1.6l at 125hp doesn’t pick up anywhere near my 216GT at 116hp though admittedly the latter is a diesel turbo but the layman in me feels it’s the torque differential of 151nm vs 270nm that makes the difference.

 

And my conclusion is based on normal day to day driving involving taking off from standstill, overtaking n changing lanes which are staple fare for most of us.

 

What you perceive as the torque differential can also be stated as Horsepower differential ​at the lower rpms.

 

Basically the 216GT is putting out more horsepower at 1k to 3k rpm compared to the civic.

 

In the end, it is still the horsepower that is moving you. You can have all the torque in the world but if you have low horsepower you aint gonna move.

Edited February 18, 2018 by Ake109