How to read torque curve graph

4th is 1:1, is the gear dynos are done in

>Why would you stay in gear as the torque drops off?
because horsepower is what matters :^)

By shifting at redline it makes you more likely to be in peak torque when you get to that next gear.

So torque is what gets the car moving, but once you have the momentum built, it doesn't matter as much?

Aren't torque and horsepower more or less the same thing? Or at least you get horsepower from torque, right?

Then what is this?
youtube.com/watch?v=lpB1yR9Sz9Y

horsepower is a measure of torque overtime

Torque times RPM divided by 5252 equals horsepower

That means that at 5252 RPM on any engine horsepower ALWAYS equals torque
this assumes torque is in lb-ft and mechanical horsepower

Torque is a derivitive of power. Engine torque dosn't matter at any speed only wheel torque and thats just related to engine power and speed.

user getting BTFO is what

But torque at the tires is affected by gearing. Since horsepower is a measurement of work over time, the peak horsepower is more important for getting the mass of the car to increase velocity as fast as possible. Peak torque is irrelevant for drag racing, you want torque to stay up in higher rpms for more power.

Jesus, this is confusing.

HP is torque x rpm / 5252, right? I would have assumed that hp would be linear, but as torque drops off and rpm increases at a stead rate, I would think that HP would also drop, but it doesn't. It continues increasing at a linear rate. What gives?

Okay, that makes sense. An explanation in understandable terms.

So why does torque drop off if you keep the engine revving?

That's an ad... lol It's to show off sound.

An advert not a dyno pull.

wrong 4th is not always 1:1

Also torque is meaningless without an RPM number next to it.
My impact wrench can do 700lbs of torque does that mean its a hand held hellcat? No

Horsepower is the only number that actually matters for performance.Torque is a useless stat meant to self trucks
Diesels make a ton of torque and little horsepower because they dont rev for shit due to the fuels flame speed.
You can always get more torque by simply changing the gear ratios but you cant get more horsepower by change the ratio because its connected to an element of time. IE RPM

it's more complicated than that
the graph shows how torque you have at the crank you need to multiple that by the ratio of each of your gears
when the torque in the next gear is greater than the one in gear your in then you shift but redline usually comes first that why on most engine you shit at red line for optimal acceleration

torque is pretty tangible to me more than horsepower
but horsepower isn't complicated either

You don't need to know, it's obvious you'll only use it for more shitposting

Ignore the 5252 as that's hust unit conversion. If you multiply 1000rpm by 20 units of torque tos get 20,000 units of power if you multiple 1500rpm by 15 units of torque you get 22,500 units of power.

>torque is pretty tangible to me
Yeah okay mr, you have a dynamometer inside your head do you?

HP goes up because RPM goes up

If torque is flat then the HP will ramp up with RPM
If torque is falling at a steady rate HP will be flatish
If torque is flat then suddenly ramps like on a high boost small engine with a big turbo HP will ramp even faster

More air in means more fuel in means more power out
Notice as boost pressure in this chart comes up the power follows almost exactly?

>So why does torque drop off if you keep the engine revving?

Normaly due to restrictions in air flow through the valves.

Okay, that adds some perspective.

Because the rpms increase. Torque is a force. Think of a single cylinder 2-stroke engine. Every time it does one revolution, it gives one torque pulse. If it is spinning faster, it gives more torque pulses per second. As the engine spins faster, the torque pulses are also stronger due to the engine being designed to make power at higher rpms. Once a certain rpm is reached, the peak force of each torque pulse has been reached. After this, each one gets less and less as rpms go higher and higher. But, even though the pulses are getting weaker, the engine is spinning faster, so there are more torque pulses per second, which means more overall torque is applied. Eventually the dropping force of torque pulses is too much, and power starts to decrease as rpms increase.

dude you can feel heat but you don't have a thermometer inside your head

you can feel a force and torque is just a force that turns

>you can feel a force
You are feeling horsepower. Fuck off.

jesous that must be a shit drive.

>Measuring torque in newton meters while measuring power in horsepower
Wew lad. When will you cucks learn that metric is a steaming pile of feces?

Hey there trailer trash underage rapist

Okay, then can someone explain this to me?

I'm using these because they're the only figures I can think of off hand.

S550 Mustangs:

V6 models makes 300HP & 280 ft/lbs of torque.

Ecoboost makes 310HP and 320 ft/lbs of torque.

Does that mean that the only tangible performance gain is 10HP?

I feel like the torque has to mean something because if not, what's the point of offering the Ecoboost as an engine, especially since it weighs more than the V6?

This
Race engines pull all the way to mechanical limits say 9,000 RPM

street engines need enough low end torque/power to lug the car around at non racing speeds hence mild camshafts and small intake and exhaust ports

More aggressive cams add a shit load of power to most american V8s because they come with mild cams stock
The bigger the cam(mainly duration not lift) the more torque the engine makes at higher RPM so... the more horsepower it makes because the torque band is shifted right.
Honda VTEC is cool because the engine has basically two sets of cams a mild cam lobe for fuel efficiency driving but when you hit higher RPM like 5,500 it hits vtec which switch the cam profile to basically a race cam grind which allows you to rev to 8,500 and make power.
If you had a single cam profile and needed high rpm the car would run like shit at 2-3,000 normal street driving rpm and idle like aids

Why arn't you using KW to measure powet Impirial is shit and should have been dumped decades ago. Only an idiot wouldn't know SI is superiour in every way.

Notice the PS next to the HP?
That's metric horsepower.
That's how metric power is actually measured you fucking coon.
I swear Australians are fucking retarded.

Is there any way to combat that? Forced induction should be able to fix that, right?

>Does that mean that the only tangible performance gain is 10HP?
No not necaseraly it may make more power over the V6 at other points in the rev range, you can't tell a lot from a single data point for each engine.

I kinda like it though, but they suck in traffic.

try touching anything you know what you feel ?
the force in Newton that you apply to this object
try picking up any object now make it turn with one hand and hold it with the other do you know what you feel ?
it's torque in N.m

yes sort of 10hp but also the shape of the powerband

The ecoboost engine has a much MUCH flatter torque curve so its making more torque at a lower rpm which is great if you have a two or three speed transmission. Modern transmissions are 6+ gears so you only need a narrow power band to stay in the torque curve when you shift.

If you tried to race say in 5 gear from 1,500 rpm to say 6,500 rpm the ecoboost would rape the mustang but if you raced from 4,000-6,500 in 1st 2nd 3rd 4th it would be a very close race
dont be made fag

Okay, I understand your explanation.

It's just an odd thought that each "pulse" would get weaker as the rpm increases, past a certain point.

When you press the gas pedal, the car picks up acceleration, thats horsepower you are feeling kid

Just stop posting

What has metric HP got to do with SI units? I'll give you some time as you are hard of thinking.

Yes forced induction helps but there is what is ckown as choked flow in fluid dynamics, above a flow rate you have progressivly more losses due to internal friction within the air. It's one of the main reasons F1 engines have huge bore to strok ratios as a big bore lets you have big valves, it's also why multiple valve heads are common as you can get nore valve area with 4 valves per cylinder than 2.

torque means nothing

Sustained torque at the wheels is what moves a car not just single blip of torque ones

Sustained wheel torque is called horsepower

Is that why cammed cars have that irregular clanking sound at idle? Because it's just not designed to run at such a low rpm?

Horsepower is a unit of power, like watts.
Power is energy over time, or in other words, how much energy you're putting out per second.
In order to get a car moving you need to give it kinetic energy. Kinetic energy is the energy of movement. So how fast you accelerate is related to how fast you're adding kinetic energy to the car. Energy per time. Power.
Torque is rotational force. It doesn't really matter to the driver, except that more force can make it easier to overcome the frictional force holding the tires to the road (i.e. spin the wheels.)
Anyone who talks about how you can 'feel the torque' of an engine doesn't know what they're talking about.

What he is actualy feeling is a linear force causd by horsepower.

not you fucking retard what you feel is your inertia try to resist the acceleration of the car
it's a fucking force
you just don't feel energy you dumb fuck
and i was talking about what you feel in a car but what seems more tangible to me
just start thinking

flow is increased squarely with pressure
Only reason you cant run 200 psi of intake pressure is because heat not because the engine reaches a certain max flow potential
Remember ALL engines are boosted even NA ones. NA means naturally aspirated that is atmospheric pressure is what the "boost" pressure is which is around 14.5 psi. Engines pull a near perfect vacuum at the head of the valve. More pressure behind that means more air pushing into the vacuum

Good point. Here are the two side by side.

hp = torque * rpm / 5252 (iirc)
but that's when you measure torque in freedom units not in this commie garbage.

>~1500hp @7500 @~2bar boost

This is because the engine is running out of breath. It is spinning faster, thus the piston is going up and down faster, burning a mixture of air and fuel faster, and the intake port, fuel metering, air intake and all that can only flow so much air. Purse your lips and inhale sharply, there is a restriction and you can only inhale so much air so quickly. Now open your mouth and inhale sharply. Your restriction is less. Think of that in terms of adding your cold air intake, headers, exhaust, ect. Now, imagine you were inhaling sharply with a leaf blower sealed to your face. Your lungs would inflate pretty fast, but you might rupture something and die. Think of that in terms of adding a turbo kit.

You keep saying tangible, you have no idea what youre fucking saying.

Stop posting

Here's your standard Mustang lineup.

You're talking about a $12k CAD difference from top to bottom.

i wasn't talking about what you feel in a car
but you don't feel energy you feel how it act which is acceleration

cammed cars idle poor because they dont have enough vacuum at idle when you add in a large cam
normally you have 18+ inches of vacuum at idle but with aggressive cams this can drop to as low as 5 inches

Dont fuck with 4g63 bruh

technologyandracing.blogspot.com.au/2011/02/one-robust-4g63-engine.html

Exactly. And, they often blow some of the intake charge right out the exhaust port at low rpm. Cams meant to move lots of air at high rpm are very inefficient at low rpm.

It's a trade off, like anything else.

maybe tangible isn't the right word
i mean it's something more concrete than Horsepower because you can feel it

>not because the engine reaches a certain max flow potential

thats not true at all. valves are pseudo-laval nozzles and there exists an inlet pressure such that the flow would be supersonic. so there is an upper limit to intake pressure.

KG per CM not PSI
its about 80psi of boost

i don't mean you can feel it in your car
i mean you can apply torque with your hand

>i mean it's something more concrete than Horsepower because you can feel it
Kill yourself. If anything is 'concrete' it is power because its what makes the car fucking move.

to make 1500hp at 2 bar it would need to make 500hp NA.
what are the chances a 4G63 can do that at 7500rpm

When I pick something up, I feel its weight in pounds, not kilograms.

sure at that far extreme but engines are designed like you said with large bores to allow large valves which given the cylinder volume I dont think you would ever hit that limit

Some diesels are running 250+ PSI of boost pressure with very linear gains still happening

>to make 1500hp at 2 bar it would need to make 500hp NA.
volumetric efficiency doesnt work like that. you can stop posting too.

SO looking at the torque curves and your explanation, the Ecoboost was designed to have more low end torque?

Horsepower's made from gasoline and forged steel, not concrete.

ottomh 1kg/cm ~ 1bar.
so no.

I love that explanation.

oh god dude now you're just trolling
you don't feel the mass of an object anyway you feel it's weight in newton
i won't bother to explain my point of view anymore

Yes, it's designed to drive better.

The side is not in bars its in KG per CM

Again its like 80 psi of boost

Volumetric efficiency absolutely does work that way.
Come back when you finish high school and do this shit day in day out.

Which gives it more horsepower over the rev range.

fucking hell you are one illiterate piece of shit, i'll give you that.

gasoline and air
and what your produce is pressure which apply a force on a piston then a crankshaft which convert it to torque which spin your wheel s

Yes... all that space between the two power curves is important.

And the difference between the two power curves is a function of the torque.

I can't believe no one posted this equation yet.

>pic related (units in HP and Ft-lbs)

ALL AMERICAN AIRCRAFT SPEC FORGED STEEL

I have to say that I'm proud of you, Veeky Forums anons. Usually these threads go straight to bro-science. Keep up the good fight.

Nope.

>Come back when you finish high school and do this shit day in day out.
I learned how to read units of measurement in primary school. 3.2 kg/cm is not 2bar.

Did your college professor write that equation out?

You've got a good point.

Thread on the entire setup
Says it made 1400~ on 57PSI
IIRC it ended up like 2khp at 80~ psi

evolutionm.net/forums/evo-dyno-tuning-results/447351-highest-hp-4g63-engine-2007-a.html

No. In a boosted engine, higher pressure is a result of more overall restriction to flow through the engine and the turbine in relation to how much air the compressor wheel is forcing in. So, an engine with large cams and a more efficient and usually larger turbine will have less restriction, and lower pressure when running the same compressor, yet make a shitload more power. This is why on say, a Civic Si, the cheaper turbo kits make like twice the pressure of the better kits and a lot less power. They have cheap, restrictive turbos.

kg/cm is torque though i think the graphic doesn't display the 2
that being said 1 bar is roughly 1kg/cm2

Its all about the exhaust flow with a bigger turbo
Pressure is pressure on the intake assuming its the same temp. Smaller turbos will run a higher pressure ratio of exhaust PSI to intake PSI. 3:1 is pretty high but normal for a small factory turbo that is if you have 20 psi intake you would have 60 psi pre turbo exhaust back pressure. Some very good medium size turbos will run near 1:1 at least up to 15ish psi of boost depending on the engine size ect

Turbo flow rate tells you the amount of air in lbs the turbo flows and gives you a rough estimate of the power the turbo can support. Remember air = fuel = power.

I didn't say mass. I said weight.

Oh it's those Greek guys, yeah they're generally regarded as being full of shit.
Even 1400@57psi seems like an exaggeration. That would be 350hp NA which again would be highly unlikely at 8500rpm, even on race gas.
Assuming it's still a 2 litre. I don't know how high you'd have to rev to make those numbers it but it would be over 10k.

3.2kg/cm2 abs = 3.1 bar abs = 2.1 bar boost
so yeah, it pretty much is you dumb faggot.

disregard this, it would be 280hp NA, which actually might be possible.

pounds is mesure of mass
weight is mass x gravity but it's being use incorrectly by every one which doesn't really matter because gravity is almost the same everywhere on earth

IIRC it was nearly 11,000 rpm

If I member right it was also being sprayed which changes everything
Nitrous is cheating in terms of engine dynos ect
Spraying more oxygen without having to deal with VE or any other issues associated with cramming more air in is fake news to me.

I can tell you've shitposted about this before.