How do you increase Torque?

[henk4]

I always thought for max acceleration, the best way to drive was when you select a higher gear the engine is near or close to maximum torque then up change again at max power etc. The powerband of the engine Ive been told is between max torque and max hp.

If an engine is making max torque at 3500 and max hp at 6500, the powerband of the engine is between 3500-6500 rpm or it accelerates the fastest between those given figures.

I know a lot of racers that have spent many laps changing gearsets so that their motors are in the sweet spot between max torque-max hp, from what some of you guys are saying is the best time to upchange is at maximum torque which in between 3000-4000 rpm and that max hp is irrelevent.

sounds like another heretic vis-a-vis the Hightower gospel...

[2ndclasscitizen]

from what some of you guys are saying is the best time to upchange is at maximum torque which in between 3000-4000 rpm and that max hp is irrelevent.

No, no one here is saying that all. I think, from all the mostly random and often contradictory posts he makes, hightower believes that power and the power curve of an engine are the be all and end all, with torque merely secondary to that, where in reality, both are equally important in a good engine, and it happens that in many cases, focusing on and properly utilising the torque of an engine can prove much more effective than merely concentrating on how powerful it is.

[charged]

sounds like another heretic vis-a-vis the Hightower gospel...

Definetley not saying that, but some of the posts here are saying once you get to max torque its time for an upchange, which will put you below maximum torque for the next gear. Short shifting under certain conditions is beneficial but for max acceleration changing at or close to maximum HP not redline will put the engine in the fat part of the torque curve, that is all Im saying

[henk4]

Definetley not saying that, but some of the posts here are saying once you get to max torque its time for an upchange, which will put you below maximum torque for the next gear. Short shifting under certain conditions is beneficial but for max acceleration changing at or close to maximum HP not redline will put the engine in the fat part of the torque curve, that is all Im saying

and which is the same I was saying a couple of posts earlier

"his sums it up very nicely....you don't need to redline a car when the toque is there..My maximum power sets in at 4000 rpm....and max torque at 2000, so shifting at 2500-2800 gives me the best results. That is what I meant by driveability, that you can move forward in a fast and comfy way, without having to worry about engine parts flying through the car as a result of constant flooring...."

[charged]

true about parts flying out, I was talking more about race applications

[henk4]

true about parts flying out, I was talking more about race applications

I know, but I think the majority of us has only walked on a racetrack...

[SlickHolden]

I read a bio of Dyno Dave Bennett of Perfectune (cam & cyl head designer/manufacturer of much repute) who in the sixties used to drag a stock Monaro 327, among others. After attaching an accelerometer to the windscreen he noticed it pulled hardest around the torque peak, so instead of stretching it to redline he always upshifted it at 3500 revs, and was basically unbeatable in his class

I would like to try that but i'll need a manual first.. With the Auto it's important to get some good rpm out of 1st gear or it drops to low in the revs, You might even waste 1 second but it jumps better into 2nd gear right in the Torque zone. But if you could keep it around the Torque area you would go great.

I bought my first diesel car in 1985....

And you have never looked back.

from what some of you guys are saying is the best time to upchange is at maximum torque which in between 3000-4000 rpm and that max hp is irrelevent.

If i had a manual i would try it to see, But with auto it's impossible, But for me the best acceleration is in the best torque area not the best power area.
I still shift around 5000rpm because it's better into 2nd.. Even though max torque is 3600rpm it still is high up above 4000rpm, It just dies off towards 5000rpm and you can feel it. But a few hundred more revs from 1 gear is better into the next, Now that might not be all cars just mine?.

[hightower99]

I'm going to keep on saying this during the entirety of my post so you don't miss it:

Without torque, you have no power. No energy x however long you like still equals zero.

----''----

Guess what: Torque is not equal to work! and obviously without a torque componant you have no power (that was the entire point of the post you responded to [I guess that slipped your mighty intellect ])

All power is, as you yourself put, the rate at which work (in the case of an engine, the torque of the engine) is done. Are you ready? Here it comes again: Without torque, you have no power. No energy x however long you like still equals zero. Once you hit the torque peak, it drops, acceleration decreases, but power increases.

Again Work is not Equal to Torque. Yes without torque there is no power (I still don't know why you want to repeat that... I didn't say that power didn't need torque) Acceleration decreases only because of increased rolling resistence, wind resistence and friction losses in the drivetrain and the fact that the energy requirements go up eponentially. If power goes up you are doing more work per unit time. That fact is not up for discussion.

Torque is the force exerted downward by the piston during the combustion stroke, the force that turns the crank, turns the gears, turns the driveshafts, then turns the wheels. Torque is the force that is applied to a nut when I apply pressure on a spanner. Simple dictionary definition: twisting or rotating force.

Yes and No. Yes torque is a force, no it doesn't do any work on it's own. Torque is the force with which the wheels, gears ect. are turned With not turned By.

8QUOTE=2ndclasscitizen]Of course not, if it didn't continue to happen (i.e power) the car/bike/boat wouldn't move[/QUOTE] Exactly my point.

A good power curve will come from a good torque curve. While it may be really boring to drive, an engine with a dead flat torque will offer much more accelerative surge for longer. Ever driven a big diesel truck? Dead smooth constant accleration whilst you're in the flast part of the torque band, much faster than if you rev the nuts off it.

Good so you agree that power is what you want at the end and that tuning the torque curve to produce a good power curve is what needs to be done.

I am happy you agree

What exactly are you trying to prove? That power is better than torque? Why not have both? Is that not the reasoning behind twin turbo systems, twincharging, and a major reasaon for having variable timing systems? To give good torque and therefore good low speed flexibility and acceleration but still allow the engine to work well at high rpm to create lots of power.

I am trying to get people to realise that Power is what it is all about. That grading engines by peak torque is a completely useless thing to do.

[Slicks]

Again Work is not Equal to Torque. Yes without torque there is no power (I still don't know why you want to repeat that... I didn't say that power didn't need torque) Acceleration decreases only because of increased rolling resistence, wind resistence and friction losses in the drivetrain and the fact that the energy requirements go up eponentially. If power goes up you are doing more work per unit time. That fact is not up for discussion.

Do you even realize what your saying? Your doing more work because your making the same torque at a higher speed. Your car does *NOT* accelerate on the power curve, it accelerates *EXACTLY* on the torque curve, you can feel it. Once your of age to drive a car, test it out and come back to us.

I am trying to get people to realise that Power is what it is all about. That grading engines by peak torque is a completely useless thing to do.

And grading engines by peak power is equally stupid, because it doesnt show how hard a given car will accelerate. Out of car A and B, which will be quicker? Notice both are making the same peak torque and same peak hp:

Im trying to get you to realize that your car's acceleration follows the torque curve exactly, there is NOTHING you have given me to show otherwise.

[henk4]

[I guess that slipped your mighty intellect ])

If you continue to include such sentences in your post, then I am afraid a ban could be imminent.

[nota]

true about parts flying out, I was talking more about race applications

Definately put me into the racetrack walker/talker category and I'm no scientist either but to share fwiw here's the relevant bit of that Perfectune bio, typed verbatim

Then on August 2 in 1968 he bought a brand new HK GTS 327 Monaro. He took it home and "ran its ring off" on the dyno, drove it across [from Melbourne] to Mt Gambier and back. them ran it on the dyno again. The following weekend he hauled it to Calder Raceway and, on the Dunlop Red Streak tyres [OE crossplies] and with the mufflers off, ran a 14.46 straight off the trailer to become the first Monaro on a drag strip

While Bennett was now a committed drag racing fan, he was also keen to stay involved in other motorsports and, with BP sponsored co-driver Henk Woelders, he entered a six-hour endurance race at Sandown, where they became quickest in practice

"Everyone else was running their engines out to 5500 rpm, because that's where the tacho was redlined, but we never took ours past 3750 rpm. That's because we had a little device which you stuck to your windscreen with a suction cup. Basically it was an accelerometer and when your car stopped accelerating the needle dropped - and that's when you changed gears. On the dyno we found that this was right on the top of the torque curve. It became one of my secrets of drag racing success as well"

"After 11 laps we were nine seconds ahead of the Porsches and other Monaros when a rear brake lining broke off with Henk driving and the car speared off the the end of the main straight at about 130 mph. We then took six seconds off the lap record at Phillip Island before the motor, which still hadn't had the rocker covers off, blew up badly, breaking the cam into seven pieces"

Not pertinent and hardly conclusive either but for historical trivia alone I'll chuck in this bit from 1968 Bathurst winner Bruce McPhee interview (also Monaro 327)

Q:
Harry Firth says you also drove to the engine's peak torque curve and apart from the straights in top gear, you were only revving the engine to 4000 rpm or so

A:
"Yeah, he's right. It was a big beefy engine with plenty of torque, so there was never any need to rev its head off. You just had to keep it in its sweet spot"

I recall some print I think from Frank Gardner's Castrol Racing Driver's Handbook, an excellent read btw. Can't find my copy now but relevant for this thread discussion imo, the proposition goes something like this:

'Take two theoretical cars which are otherwise identical in every possible respect - in dimension, weight, gearing, and aero etc. Both engines develop an identical 100hp, the only difference between them is that theoretical car 'A' is 2 litre and car 'B' is 4 litre, with car 'B' producing twice the torque of car 'A'. Theoretical car 'B' with same hp but twice the torque will accelerate at twice the rate of car 'A'

[Alastor]

'Take two theoretical cars which are otherwise identical in every possible respect - in dimension, weight, gearing, and aero etc. Both engines develop an identical 100hp, the only difference between them is that theoretical car 'A' is 2 litre and car 'B' is 4 litre, with car 'B' producing twice the torque of car 'A'. Theoretical car 'B' with same hp but twice the torque will accelerate at twice the rate of car 'A'

In that scenario Car B makes twice the average power compared to Car A, because Car A is at best operating at half the engine speed that it makes peak power at.

So that example shows that a car that makes less average power is slower than a car that makes more average power, I don't think anyone is going to disagree with that.

[hightower99]

Do you even realize what your saying? Your doing more work because your making the same torque at a higher speed. Your car does *NOT* accelerate on the power curve, it accelerates *EXACTLY* on the torque curve, you can feel it. Once your of age to drive a car, test it out and come back to us.

I'm 19 been driving since 16 and I disagree with you. The cars I have had have not accelerated exactly on the torque curve at all.

And grading engines by peak power is equally stupid, because it doesnt show how hard a given car will accelerate. Out of car A and B, which will be quicker? Notice both are making the same peak torque and same peak hp:

No it isn't stupid to make general comparisons based on peak power. The engine with more power will accelerate faster, go ahead try finding an example where this isn't true. Car A will of course accelerate harder over the whole range because it makes alot more power than car B at the same engine speed. Car A and B will be accelerating at exactly the same rate when they both hit peak power at the same speed.

Im trying to get you to realize that your car's acceleration follows the torque curve exactly, there is NOTHING you have given me to show otherwise.

I have given you the equations that prove it. You haven't shown a single equation that shows that torque alone is responsible for acceleration.

But here I will give you another proof. Motive force (F) at the wheels is equal to power (in Watts) times drivetrain efficiency (percent) divided by vehicle speed (in m/s). This force is used (partially during acceleration) to overcome running resistence (which is the sum of aerodynamic resistence, rolling resistence and climbing resistence). So acceleration is equal to motive force minus running resistence divided by vehicle weight (in kg) times the rotational inertia coefficient.

This is in the bosch automotive handbook, if you disagree.

[SlickHolden]

I think diesel cars have proven that torque is more important then power..

Trucks are not huge on power but they are with torque, And that is what moves them..
Mates truck has only 300hp, But tips 700Nm torque.. If power was more important to a truck then it would have 700hp and 280Nm torque.
And if anyone has been in a semi with no trailer will know the acceleration them things can have it's not power in this case.

[Cyco]

hightower99, how is a simplistic equation better than repeated precise measurements?

The Bosch handbook is good, but I'll take nota's repeated acceleration measurements every time. Measurements that show that acceleration happens fastest at peak torque, not peak power.

Is not scientific process the taking a measurement and if the theory doesn't fit then change the theory, not abusing those taking the measurements?