BHP and Torque

great advice · 11 Mar 2006 at 09:54

Your avarage 1000cc motorbike has around 120bhp and 60f/lbs of torque

Bear · 11 Mar 2006 at 10:08

great advice said:
They keep that under wraps but i think its about 700bhp and 500/lbs. Torque curve and power delivery will be smooth as a baby;s bum

I never said they have equal amounts but the torque figure is equally as important as the BHP figure when it comes to racing.

I never meant to imply that you said anything about bhp and torque being equal. I was trying to say bhp isnt willy waving, its all interlinked as shown by the equation.

I would guess the torque level of an F1 car would be less than half of what you suggested due to the amount an F1 car revs to.

To gain more power in an engine, you can either increase the torque or increase the revs or even both through what ever methods you like, the choice of which would depend on the application.

Stonedofmoo · 11 Mar 2006 at 10:53

A good engine will have almost equal amounts of bhp and torque imo. It's the most drivable combination

penski · 11 Mar 2006 at 10:54

Stonedofmoo said:
A good engine will have almost equal amounts of bhp and torque imo. It's the most drivable combination

Peak?

Constant?

:/

*n

Stonedofmoo · 11 Mar 2006 at 10:57

Well without having a specific engine in mind, or a dyno graph to analyse shall we say peak?

great advice · 11 Mar 2006 at 11:45

Stonedofmoo said:
A good engine will have almost equal amounts of bhp and torque imo. It's the most drivable combination

Thats ideal for a stop/start commute but not always ideal for racing

Simon · 11 Mar 2006 at 13:23

great advice said:
They keep that under wraps but i think its about 700bhp and 500/lbs. Torque curve and power delivery will be smooth as a baby;s bum

Lucky to get over 300lb/ft on the old v10s. the v8s will have even less torque. It's the revs that make the bhp which allows shorter gears.

There's more to it than just engine torque, wheel torque is what will accelerate the car

L Plate · 11 Mar 2006 at 14:06

great advice said:
Your avarage 1000cc motorbike has around 120bhp and 60f/lbs of torque

However its delivered very differently

your average ZX10R or GSXR1000 runs about 175-180bhp and knocks out around 80ft/lbs of torque

however V Twins deliver it differently in that the bhp remains lower but due to the twin cylinder setup you get bigger torque figures, my RSV1000 puts out 118bhp at the crank and still gives around 78ft/lbs.

torque wins races, BHP does increase chances, but higher torque figures makes for better willy waving

Alibaba99 · 11 Mar 2006 at 14:20

Acceleration is proportional to the rate of work done, which is the basic definition of power. For an acceleration run 0-60, 0-100 or whatever the engine will be kept at around the point of peak power so it is the max power level which will determine the acceleration rate. A CTR and Focus RS have very similar weights and power levels, and not surprisingly have very similar acceleration rates, despite a huge difference in the amount of torque they produce.

In normal driving, if you are being lazy with with the gear lever, then it is helpful to have a decent amount of low down torque (this also means that the power at these levels is pretty good) to accelerate the car out of corners or past slower traffic. If you are willing to always use the gears properly then a car which is torque lite can also be driven cross country very rapidly, it just won't be as relaxing if taking things easy.

great advice · 11 Mar 2006 at 15:04

L Plate said:
However its delivered very differently

your average ZX10R or GSXR1000 runs about 175-180bhp and knocks out around 80ft/lbs of torque

however V Twins deliver it differently in that the bhp remains lower but due to the twin cylinder setup you get bigger torque figures, my RSV1000 puts out 118bhp at the crank and still gives around 78ft/lbs.

torque wins races, BHP does increase chances, but higher torque figures makes for better willy waving

Didnt realise they are pushing out that much power nowadays! ive got a K1 GSXR1000 which has been modded and thats 159bhp at the wheel!! Think they were about 120bhp off the production line??

I know V-twins are all about torque, its what makes the SV650 a great commuter.

Oakesy2001uk · 11 Mar 2006 at 18:43

put it this way, valetino rossis bike could have 300 bhp or even more if the wanted, but it would be useless as he would not be able to get the power down, instead they choose a nice flat curve with plenty of torque and abou 250bhp. oh yea, and 150 kg, now thats fast!

I tottaly agree, torque is for men and bhp is for willy wavers to a point. but bhp is still usefull (again to a point) but torque figures should be talked about more.

L Plate · 11 Mar 2006 at 19:04

great advice said:
Didnt realise they are pushing out that much power nowadays! ive got a K1 GSXR1000 which has been modded and thats 159bhp at the wheel!! Think they were about 120bhp off the production line??

I know V-twins are all about torque, its what makes the SV650 a great commuter.

Bikers are no different when it comes to willy waving, its just they tend to do it to cage drivers

I always keep a spec list hanging around to compare just how quick modern bikes are, how much weight they lose, how much bhp they gain, and yet they dont improve massively in the amount of torque they put out in relation to the older bikes,

and why?

simply because there is only so much torque a person can take, before your hands would have to let go of the bars!!!

Suzuki GSXR1000K1 145 at the wheel - 81.0ftlb 170kg
Suzuki GSXR1000K2/K3 146 at the wheel - 75.2ftlb 168kg
Suzuki GSXR1000K4 144 at the wheel - 74.8ftlb 168kg
Suzuki GSXR1000K5 161 at the wheel - 87.0ftlb 166kg

Kawasaki ZX-9R C1 (98) 144 at the wheel - 77.0ftlb 183kg

Aprilia RSV1000 (99) 118 at the wheel - 78.5ftlb 180kg

minidan · 11 Mar 2006 at 19:05

torque is a word made up by diesel drivers to convince people there cars or quick

Spanker · 11 Mar 2006 at 21:26

Give me 250bhp at 5,500rpm/258lb ft (350Nm) torque at 1,900-4,000 rpm and i would be a happy guy

Give me at my back wheels and i would be happier still.

Scania · 11 Mar 2006 at 21:58

A Scania R124/LA420 produces Maximum net power: 420hp(kW) at 1,900rpm and
a maximum net torque : 1,475lbsft (2000Nm) at 1,100 to 1,300rpm.

It will easily pull 50+ tonnes.

A BMW M5 (e60) produces upto 507BHP and 520Nm of torque but could'nt tow the 8tonne Scania tractor unit, never mind its load.

Its not down to the power output at all, its all down to torque, the more torque your engine produces, the better.

minidan said:
torque is a word made up by diesel drivers to convince people there cars or quick

No mate, torque is why trucks don't run on petrol.

Bobbler · 11 Mar 2006 at 22:28

minidan said:
torque is a word made up by diesel drivers to convince people there cars or quick

Heh heh.
I drove a TDCI that the missus had last week on hire. Yes it had torque, it kinda pushed you in your seat for about a fraction of a second and then you had to change gear again. Gave everything it had in about a 1000RPM range and then just petered out
You just sort of sat there, here it comes....WOOHOoo?!?!..D'oh!
Gah! Rather have my power a bit longer and work for it thanks.

merlin · 11 Mar 2006 at 22:43

If I ever feel the need to buy a caravan I'll be sure to look a Diesel car up.

Till then I'll stick with petrol and enjoy a clear rear view mirror.

Dolph · 11 Mar 2006 at 23:08

Simon said:
Lucky to get over 300lb/ft on the old v10s. the v8s will have even less torque. It's the revs that make the bhp which allows shorter gears.

There's more to it than just engine torque, wheel torque is what will accelerate the car

This man speaketh the truth

Wheel torque is the key and it's dependant on both engine and gearbox. That's why a petrol with a large rev range, short gears and less torque will destroy a diesel with a short rev range, long gears and more peak torque unless you're doing stupid figures (like 30-70 in top gear).

BHP is a product of torque and revs, and is a better indictator of flatout performance than torque. Torque can be a better indicator of in gear performance, however it's all very much gearing dependant.

DreXeL · 12 Mar 2006 at 00:26

penski said:
"BHP sells engines, torque wins races."

Very, very true.

*n

Ahh, the old 'It's all about torque, BHP is just pub talk' BS again. Bear, Simon and Dolph have pretty much summed it up, so I wont really add much.

In a car with a high revving engine and short geraing, lack of torque only matters if you are afraid to stir the stick.

My engine only produces around 250lb/ft of torque, but that torque is very constant and flat thruout the rev range, hardly dropping off at the top:

(Credit goes to Simon for knocking that up from the dyno graph in my sig)

The high rev/high BHP/flat torque curve means it kills lots of things with more 'all conquering' torque.

Massive torque and low BHP? No thanks.

Simon · 12 Mar 2006 at 12:36

Derv's don't have powerbands like the one in my sig either.

BHP and Torque

Man of Honour