Charlie Chalk

iTrader: (1)

I don't really understand whats best to have?

More 'bhp', or more 'lbft' ?


If you got a 300bhp / 274lbft engine, and a 300bhp / 344lbft engine, what would be better to drive?

Is there a difference in how it drives or performs?


Discuss, Or if theres been a thread, please link

Benni

Stu did a big feature for Fast Ford. Have you seen it, it's an intersting read.

Benni.

Chip

iTrader: (3)

The 344lbft one would pull better lower down, the lower torque one would rev better.

Geared correctly for each, they would be the same speed.

Chip

iTrader: (3)

PS

If anyone ever says
"Bhp is good for down the pub, but torque wins races" ignore them as they havent got a fucking clue so are just trying to sound clever repeating random old american sayings with no basis in fact for most forms of motorsport

pa_sjo

What's more important is the torque CURVE.. this is what makes the car drive how it does.. if you have a flat torque curve (ideal really), then you end up with linear acceleration.. if you have a peaky torque curve (queue high compression jap crap), then you get a big surge of acceleration (and usually wheelspin) but then it just dies off quickly.. Long, big flat torque curves are what gives you that relentless acceleration (that or an ever increasing torque curve).. Power is just a function of torque and speed..

Look at it this way.. torque is more important than power, but your power limit (choke point) is what ultimately limits your power band.. (torque curve)..

Rod-Tarry

Sorry Chip cant let you get away with that it was Colin Chapman that said that & he knew more about engines & winning races than you ever will. Whats more I totally agree with him.

Turbocabbie

Colin Chapman was very wise as he also once stated

"The secret of a successful marriage is not to be at home too much."

Stu @ M Developments

iTrader: (12)

This is a timely question as its reminded me to do something.

https://passionford.com/forum/showth...08#post3454508


Sorry mate, It was a poorly worded quote to anyone who understands power and torque Rod, even though we all understand what he was getting at.

Charlie Chalk

iTrader: (1)

Cheers everyone.




Will have a read, Cheers Stu

IAIN ABZ

Torque is a real factor, BHP is not. BHP is essentially the work done by an engine, and is a function of Torque and RPM and Losses.

Chip

iTrader: (3)

The thing that accelerates a car, is torque at the wheels versus its weight.

Torque at the wheels is a direct result of BHP and gearing, it is NOT a direct result of torque at the flywheel.
As above, BHP is work done, torque on its own is a meaningless figure without being in the context of RPM!

Stavros

Exactly. That "Torque wins races" comment is utter bollocks purely as people think of LOW DOWN torque.

Hence why diesel and XR4 owners think their cars are fast as fuck "ooooh, look how much torque i have, ill be halfway down the road before you are in the powerband" and the other gay quotes they always come out with.
When in reality they get destroyed by anyone who understands how to drive and has a bit more bhp than them.

Our diesel has 190bhp and 350lbft. It feels fast, easy to keep it in the powerband, but a similar weight car with 50 more bhp but 100lbft LESS still totally destroys it in a straight line.

4x4

so low down torque cars isn't as quick as top end torque cars?

torque talk goes over my head sorry!

Porkie

iTrader: (1)

Really? I thought it was Carrol Shelby?

I think F1 engines make that quote seem silly don't they? or any of the BEC doofloopys? they seem to go ok as well.

XRT_si

iTrader: (2)

I always thought it it was Carroll Shelby too for some reason.

Stavros

If you can change gear, yes.

But if your car makes big bhp top end, its fast, simple as.

Chip

iTrader: (3)

Carol shellby said:
Horsepower sells cars, torque wins races


Ive no idea if colin chapman said similar, but Id be surprised if he did unless it was in a very specific context, on the basis that its utter bollocks and he tended not to talk that, lol

4x4

kool! nice one dude!

your info on the 190bhp 300lbft dielsel and a car with 50 more bhp was helpful. cheers mate!

JohnnyB

F1 cars, have fuck all torque, I don't know about you but they go fucking well

Chip

iTrader: (3)

300lbft, 900bhp, roughly speaking.

with 800lbft and 800bhp, they would be slower, thats the bottom line, as they have the gearing to keep it on the boil with a peaky engine anyway, as a road car though, 800/800 would be fucking awesome and far easier to drive quickly.

foreigneRS

depends how you like to drive. some like to change up early, some like to rev.

4x4

the ones who like to rev are the ones with lower torque yes???

It's Czech Mate

You drive to make the most of what you have unless you're a gimp

Every driver would ultimately like a wider spread of torque as its easy to drop out out of the power band in a road situation where you have some unexpected situations

However ultimately is power that makes a car fast, more torque just makes it a bit more driveable in those situations where we cant keep it on the boil

AlexF

you dont get power without torque.....


torque is a turning force

power is a measurement of how much work you have done in a set time.

Chip

iTrader: (3)

Indeed

Revs and torque contribute equally to BHP.

you double one, the BHP double's too.

simple stuff, cant see why it confuses people so much TBH

AlexF

People assume they are totally differnet things as they are quoted seperatly....

Alex

JohnnyB

300 ibft from a 2.5 v8, whould have thought was a little high chip

Chip

iTrader: (3)

Perhaps we should stop calling it BHP and refer to it purely as "revs * torque"

People wouldnt argue about what was better then!

Chip

iTrader: (3)

Sorry mate, I was referring to the V10 ones, which were 3 litres.

I havent seen the figures for the V8 ones, id imagine they are about 250lbft though, 100lbft a litre is normally about the limit for N/A

AlexF

It depends on many other factors.... and indeed the use you are putting the car too!

High torque at low rpm is good for towing/off roading.

High bhp at high rpm is good for making your gears turn fast - so well suited to top speed runs etc.

Torque and BHP are different measurements of the same thing, an engines performance.

You need to look at the torque and power curves to work out what an engine is like to drive. That lets you see how well and engine will "rev" and the steepness of the graph gives an idea as to what the engine will feel like to drive.

Alex

Nash_mr2

you want a perfect ballance of BHP to Tourqe - 1000BHP and 1000NMtq - but thats almost impossible to acheaive

Stavros

Generally, if weight/gearing/etc is equal and the powerbands is the kind of thing we used to on 2litre petrol engines...

A car with 200bhp and 200lbft is generally faster than a car with 200bhp and 150lbft.
And a car with 200bhp and 150lbft is generally faster than a car with 150bhp and 200lbft.

Porkie

iTrader: (1)

Its because it was him thats why

Chip

iTrader: (3)

Its a piece of piss to achieve same NM as BHP, dont be so ridiculous.

although id say same in lbft was a nice charateristic for a road car, not NM

_DAN_

Interesting thread.

RickyLee53

EXACTLY!

Was it shelby that first said it?

BHP sells car's torque win's races.

Worse thing is, it's always the "no it all's moto".

F1 car's have less torque than my grandad's diesel, but i know which would be quicker.

The only advantage or torque IMO is you don't have to drive it as hard, i.e. can be in wrong gear and it's more forgiving.

foreigneRS

that's usually due to the torque curve, rather than the actual torque output

Chip

iTrader: (3)

The time that low down torque is vital, is in "hooking up" off the line, especially on massive wrinkle wall drag slicks.

Thats the only time really that torque IS more important than horsepower IMHO, but once you are moving, you then need the horsepower to accelerate.