Horse power and Torque

ah_wei83 SG

hi guys,,,can someone enlighten me on wat is the diff btw horse power and torque..i also see magazine that torque is measure in newton square…i knw that the more horse power the more powerful the car.but hw abt torque?and wat is used for wat?is horse power for top speed while torque is for pick up?pls shed some lights,,

thanks…................Cheers!

tofushop193 SG

http://www.procivic.com/pages-horsepower_torque/index.html

Unknown_X SG

don't really understand leh. to me, torque = pulling power from start that will aid in accelaration. hp = max power a car is able to give.

ceecookie SG

This question has been asked countless time.

tomsss SG

This question has been asked countless time.

this phrase has been used countless times as well

alleggerita SG

don't really understand leh. to me, torque = pulling power from start that will aid in accelaration. hp = max power a car is able to give.

You are right about torque. Torque is important for acceleration. Modern commonrail injection diesel engines have immense torque, hence their great in-gear acceleration. Just take a Sonata CRDi cab and observe when cabbie overtakes vehicles. It's overtaking power is nothing short of amazing.

But as for horsepower, it helps with acceleration too, but torque is more important. Horsepower affects the vehicle's ultimate top speed though. Torque is usually not linked to top speed.

So if you were to ask me, I'll take a car with more torque than with more horsepower. Though if both are in abundance, that'll be the best.

Unknown_X SG

But as for horsepower, it helps with acceleration too, but torque is more important. Horsepower affects the vehicle's ultimate top speed though. Torque is usually not linked to top speed.

So if you were to ask me, I'll take a car with more torque than with more horsepower. Though if both are in abundance, that'll be the best.

IC! thanks for the explanation. ya i realised the current taxis quite powerful, some even challenge my mark x on the expressways. KNN!

mh2 SG

torque= instanteous power

KW power= power measure over 1 second

BAsically ,it address the same issue...

that is how much motive force can your engine produce.

and we are talking about engine only.

not taking into account: tramsmission response & efficiency, gear ratio, road condition etc...

To avoid confusion, i only look at KW.

my car KW curve fall off at 3000rpm.

that is affirm by my actual driving. the DOHC engine simply provide no substantial power increase after 3000rpm.

n0x SG

torque= instanteous power

KW power= power measure over 1 second

BAsically ,it address the same issue...

that is how much motive force can your engine produce.

and we are talking about engine only.

not taking into account: tramsmission response & efficiency, gear ratio, road condition etc...

To avoid confusion, i only look at KW.

my car KW curve fall off at 3000rpm.

that is affirm by my actual driving. the DOHC engine simply provide no substantial power increase after 3000rpm.

every once in a while.. i must write in to debunk some myth... and provide the TS clearest of explanations bcos cocksters like mh2 come in and post rubbish (or jokes depending on how u view it) to mislead people and brighten up my day on an otherwise dull saturday....

so i shall start...

joke #1 torque= instanteous power

torque is not instantaneous power.. wtf u get tt idea from....

joke # 2 KW power= power measure over 1 second

units for torque is Nm NOT kW power... smlj u talking

units for horsepower is kW or bhp.... not power measured over 1 second... power is energy per unit time instead... clearly u got ur power and energy and torque units and concepts all mixed up...

to further confirm tt ur concepts are totally screwed... here comes

jokes #3 my car KW curve fall off at 3000rpm.

kW refers to horespower...so u mean ur horsepower drops off at 3000rpm.. what kinda hyundai u driving... a hyundai bus that redlines at 3000rpm ah...

most normal cars horspower drops off at redline.. a normal sedan is around 5000-7000rpm.....

what u see dropping off at 3000 rpm is ur torque curve... and the units are Nm...

so there u have it guys... i present to u the ultimate joker of sgforums...( and with a pretty thick skin too)..

now he will go into hiding knowing he is technically inferior to me by a long shot..

and will come out to take pot shots at me when someone is shooting me... and by pot shots.. are insensitive childish name callings and other non-technical stuff...

i seriously rest my case...

n0x SG

so now i shall give my version of explanation...

contarary to popular belief... horsepower does not aid torque in acceleration..

like i have stressed a lot of times... horsepower is a DERIVATIVE of torque...

u need the torque to accelerate up to speed and only at the particular speed then u are producing that amount of power...

so for example when a car specs read 110bhp @ 5600rpm... it is only producing 110bhp when u rev up to and stay at 5600rpm.. at other rpms it might be only producing half of tt bhp...

so when people say my car got XXX bhp it just gives u a rough feel of how fast your car can go maximum...

whereas for torque... u need tt to attain tt power output... and is what u feel when u accelerate...

and contarary to another popular belief... assuming u are comparing 2 engines of the same capacity... u cannot have 1 that have high torque and high power output at the same time...

here's why...

bhp = (torque x RPM) / 5250

this is the formula that governs the working of an engine... so from this formula... u can tell two things...

no.1

u want high bhp u cannot have high torque and vice versa...

which explains why type r engines have high power output but lousy torque

and explains why amg engines have high torque( a good spread across the entire rpm range) but low power output for its engine size....

no.2

look for ANY dyno chart... the power and torque curve will criss cross at exactly 5250 rpm...

hope it clears the air about everything...

nightsky87 SG

+1 to nox! Great explanation.

nyox SG

so is high torque really that useful? i found these information on the net. Taking into account both are auto transmissions.

Hyunda Sonata 2.0 CRDI (Diesel)

Max power: 140hp

Max Torque: 305Nm

0-100 km/h: 11.6s

Hyundai Sonata 2.0 DOHC (Petrol)

Max power: 144hp

Max Torque: 188Nm

0-100 km/h: 11.5s

Both vehicles have about the same max power, however the torque of both vehicles are worlds apart. How is it that their 0-100 sprint timings are so close?

alleggerita SG

so is high torque really that useful? i found these information on the net. Taking into account both are auto transmissions.

Hyunda Sonata 2.0 CRDI (Diesel)

Max power: 140hp

Max Torque: 305Nm

0-100 km/h: 11.6s

Hyundai Sonata 2.0 DOHC (Petrol)

Max power: 144hp

Max Torque: 188Nm

0-100 km/h: 11.5s

Both vehicles have about the same max power, however the torque of both vehicles are worlds apart. How is it that their 0-100 sprint timings are so close?

Firstly, good job to n0x for giving mh2 what he deserves. A shaming.

And now for nyox's question. This will have to be blamed on the weight of the diesel engine. Diesel engines are usually much heavier than a petrol engine of similar engine capacity. It's usually 100kg++ heavier. Hence the extra torque produced by the diesel engine is usually nullified by the extra weight the diesel engine carries during acceleration from a standstill.

I believe the reason why diesel engines are heavier than petrol engines of similar engine capacity is because the engine block of a diesel engine is thicker than a petrol engine. This is because diesel engine needs to be stronger to withstand the extremely high compression ratio. Diesel ignites when it compressed until it reaches a very very hot temperature, hence the high compression ratio. Petrol engines have a much lower compression ratio because fuel is ignited by a spark plug. So this is probably why diesel engines are heavier.

Diesel usually only win petrol when it comes to overtaking. During overtaking, diesel engines have more torque than petrol engines, and this makes their in-gear acceleration amazing. Especially when there's an automatic gearbox and it kicks down during overtaking. The torque of the diesel engine is so prodigious, it's sure to win a petrol powered car in an overtaking situation.

Deviancez SG

Yes, just a summary. Torque to help acceleration.

Horsepower help to achieve ur top speed.

Unknown_X SG

damn informative!

mh2 SG

Diesel ignites when it compressed until it reaches a very very hot temperature, hence the high compression ratio.

Diesel fuel is not compressed in the diesel engine, it is
INJECTED into the combustion chamber. It is the air intake that is being compressed to a high ratio. Think b4 u fart!

PS: i sincerely hope u dun follow in NOX's footstep..>> A haughty [email protected]

n0x SG

Diesel fuel is not compressed in the diesel engine, it is
INJECTED into the combustion chamber. It is the air intake that is being compressed to a high ratio. Think b4 u fart!

PS: i sincerely hope u dun follow in NOX's footstep..>> A haughty [email protected]

i am a huaghty jackass bcos u grant me the ability to... due to ur incompetent lowlife existent...

how bout instead of all these comments.. let me see u do a firm rebuttal to what i said about u...

cant??

then FCUK OFF pls....

alleggerita SG

Diesel fuel is not compressed in the diesel engine, it is
INJECTED into the combustion chamber. It is the air intake that is being compressed to a high ratio. Think b4 u fart!

PS: i sincerely hope u dun follow in NOX's footstep..>> A haughty [email protected]

Alright, read up on diesel engines. Yes, you are right. It's the air that's compressed to a super hot temperature. My bad here.

mh2 SG

Alright, read up on diesel engines. Yes, you are right. It's the air that's compressed to a super hot temperature. My bad here.

hey....

what the problem...

you are knowledgable too..

i can see your avatar is an lambo gallardo?

taken in SG?

u got a close up?

alleggerita SG

hey....

what the problem...

you are knowledgable too..

i can see your avatar is an lambo gallardo?

taken in SG?

u got a close up?

Lamborghini Gallardo is so common in Singapore now. No problem getting a close up picture of it. I don't really bother taking pictures of Gallardos anymore even though I like them.

Nowadays, cars that I think are worthy of pictures being taken are vintage cars. Like a Volvo P122S I saw recently. Heard there's only two in Singapore. But dammit I didn't get a picture of it.

This is the exact P122S I saw with the same numberplate. And it's up for sale!

http://cars.st701.com/cars/view/11958?from=%2Fcars%2Fresults%2Fpage%3A1%2Fsort%3ACar.title%2Fdirection%3Aasc%3Fcar_type_id%3D3