Sports Car Forum - MotorWorld.net

Sports Car Forum - MotorWorld.net (http://www.motorworld.net/forum/index.php)
-   Car Chat (http://www.motorworld.net/forum/forumdisplay.php?f=16)
-   -   Doubts about torque (http://www.motorworld.net/forum/showthread.php?t=6021)

marciodcmendes 02-07-2004 08:24 PM

I love miniature cars. But they are a bit expensive. I have about 50 bburagos, but it cost me lots of money. Just a question about the evo. Did you also try the Subaru? Just to know, because here in Portugal nobody has an Evo. Not even the cops! They have Imprezas. No idea why, cuz I love the Evo from day one!

zevolv 02-07-2004 08:31 PM

yes torque is force*distance(that's what the Lever Arm is) that's why ALL Torque Wrenches are exactly 1 foot long hence Torque is in Lbs per feet, foot pounds of torque get it?

zevolv 02-07-2004 08:33 PM

Quote:

Originally Posted by marciodcmendes
I love miniature cars. But they are a bit expensive. I have about 50 bburagos, but it cost me lots of money. Just a question about the evo. Did you also try the Subaru? Just to know, because here in Portugal nobody has an Evo. Not even the cops! They have Imprezas. No idea why, cuz I love the Evo from day one!

Yes I test drove the STi and the EVO and I prefered the EVO way more especially because it isn't as flashy and I have driven normal WRX's and actually liked some of the custom ones I've driven more than the STi.

deth 02-07-2004 11:02 PM

Quote:

Originally Posted by zevolv
dragsters have bitchloads of both yes. Torque is all about turning those wheels (torque=force*distance) so if your car has the power to turn the engine it can create alot of torque and that's why most larger engines have a longer stroke and that's the advantage of a long block over a short block.

firstly the longe stroke does not produce more torque solely because torque = force times distance(which is actaulyl incorrect). in fact the the propper equation for torque is torque = force times perpendicular distance, and therefore since the cylinder travels perpendicular to the motion of the cam shaft, the length of the stroke has no effect on torque in that respect. more torque is generated by engines with longer strokes b/c it have a higher compression ratio, which is the same principal as a turbo/supercharger, ie more air/fuel in a smaller area = more boom.

Quote:

Originally Posted by zevolv
yes torque is force*distance(that's what the Lever Arm is) that's why ALL Torque Wrenches are exactly 1 foot long hence Torque is in Lbs per feet, foot pounds of torque get it?

and no not all torque wrenchs are exactly 1 foot.. if you dont believe me look here. think about it, if u need to torque a bolt to 250 ft lbs , how are you going to do that with a 1 foot wrnch?! apply 250 ftlbs? damn hard if u ask me................

next time do your homework, or know what the fuck u're talking about before you post! :roll: and to think that your dad has all those muscle cars and u don't know what a torque wrench looks like?! do u have any pix of your so called dad's cars? or are you just another Donny? :twisted:

zevolv 02-07-2004 11:12 PM

OK dick shit the Camshaft has nothing to do with the stroke of an engine that is the Crankshaft and Actually the equation is just Force*Distance so on those 2 matters you can kneel down and open wide and when I said all torque wrenches are 1 foot long I meant standard torque wrenches yes you can get longer ones but they will be really expensive and not too many things on a car go over about 160. actually more torque is created because of the longer Crankshaft that's why diesel's (the kings of torque) use long blocks not short blocks so once again kneel down bitch. And I went and looked in our garage and yes we do have a 2 foot torque wrench. so it was a slight typo.

deth 02-07-2004 11:22 PM

Quote:

Originally Posted by zevolv
Actually the equation is just Force*Distance

um no....for teh sake or argument if the force parallel to the distance the torque is zero no matter how hard u push or how far is is. and es i made a mistake, i meant crankshaft, not camshaft

zevolv 02-07-2004 11:25 PM

in all my physics classes I've taken (3) and all the automotive books I have (3 textbooks) I was always taught just Force*Distance even though on a rotational basis was always stressed the equation was always just normal distance.

AND: if some dumbass takes a torque wrench and tries to push down on it to turn the bolt they shouldn't even be allowed to ride in a car.

nthfinity 02-07-2004 11:28 PM

as its been explained already, Force*Distance/Time= power aka torque. what i think hasnt been adiquately explained is how hp is derived from torque
Horsepower = (trorque)(RPM)/5252
as the power is given in rotational form, it is converted back to liniar form when say, you go down the streatch of tarmac
the engine power is lost by
By accelerating the car over a distance in a given amount of time.
Aerodynamic drag on the vehicle.

Rolling friction loss. Some of the energy is dissipated as heat in the gears, torque converter, wheel bearing, and tires.

Inertial losses. It takes energy to speed up a mass. Internal components in the vehicle drivetrain that undergo acceleration draw energy. These components include the pistons/connecting rods changing direction, pulleys, flywheel, transmission shafts, drive shaft, axles, and wheels. The mass of the pistons/connecting rods and valves/springs are always a draw on horsepower. The mass of the rotating components only draw horsepower when the engine increases RPM. Lightening up all of these components will reduce inertial losses, and make the engine less stable. On the plus side, these inertial components, once up to speed, will make your car coast further and can help mileage on the highway. But they hither acceleration so buy aluminum or magnesium rims. =P

so in retrospect, hp is little more then a differnece between torque and rpm.
when looking to buy your next sportscar, look up its torque curve... the flatter the curve, the more linear your accelleration will be, but it wont be a sudden boost of power, but a constant application. some people dont like this, and choose to buy high reving, low torque cars... tho they make decent torque, there is little startoff accelleration (do you really want to try and dump the clutch from 7000 rpms in an S2000?)
my 2 cents

deth 02-07-2004 11:30 PM

Quote:

Originally Posted by zevolv
actually more torque is created because of the longer Crankshaft that's why diesel's (the kings of torque) use long blocks not short blocks

oh dear.....u're so confused. first diesel's have more torque because diesel has more btu/lbm. and secondly diesels ahve higher compression ratios than gas engines, thats why they're so noisy. notice its the stroke that causes the higher compression and hence the torque.

mburer 02-07-2004 11:33 PM

Quote:

Originally Posted by zevolv
AND: if some dumbass takes a torque wrench and tries to push down on it to turn the bolt they shouldn't even be allowed to ride in a car.

so they should only pull up on a torque wrench ? or maybe only push it sideways ? LMAO.. and since when was mechanical competency a must for being allowed in a car :?:

nthfinity 02-07-2004 11:34 PM

jeez deth/zevlov lol calm down, we are here to have fun and learn.... so what if we are sometimes wrong...

deth 02-07-2004 11:35 PM

Quote:

Originally Posted by zevolv
in all my physics classes I've taken (3) and all the automotive books I have (3 textbooks) I was always taught just Force*Distance even though on a rotational basis was always stressed the equation was always just normal distance.

impressive, then i guess that just negates all 3 year of my mech eng studies then, doesnt it..damn..i wish i had 6 physics/technical books. and you do realize that 'normal to' is the same a 'perpendicular to' right?


where are the pix of your and your dad's cars?

nthfinity 02-07-2004 11:39 PM

Quote:

impressive, then i guess that just negates all 3 year of my mech eng studies then, doesnt it..damn..i wish i had 6 physics/technical books. and you do realize that 'normal to' is the same a 'perpendicular to' right?
lmao. Engineering is the Shit! no doubt to that. so many posts so quickly, i think ill have a drink!

zevolv 02-07-2004 11:40 PM

yes but in the equation it always just said distance that's what I meant by normal distance.

Vansquish 02-07-2004 11:45 PM

Quote:

in all my physics classes I've taken (3) and all the automotive books I have (3 textbooks) I was always taught just Force*Distance even though on a rotational basis was always stressed the equation was always just normal distance.

Care to list the textbooks you've got, and what classes you've taken? I am a physics major, and I've taken several University of Michigan Engineering school classes on mechanics in addition to my studies in physics. YOU ARE WRONG. The equation for Torque is force times the perpendicular distance to the axis of motion. That means in a simple case...say a wheel...the perpendicular distance to the point of application of the force...i.e. static friction on the road... would be the same distance as the radius of the wheel. In other cases it does not work out that way. If you want to find the torque on a dipole (something that has a positive electric charge at one end, and a negative one at the other end) in a constant electric field, the sum of the forces on the dipole comes to ZERO, but there is still torque, i.e. the thing will still rotate about its center. The torque is measured at a PERPENDICULAR distance to the center of rotation, from both ends separately. The equation for torque is T = R X F where "X" means "cross product" and the force "F" must be applied at a perpendicular to the lever arm "R". If you would like a more thorough explanation of what torque is, and how to find it, I will be more than happy to look it up in any of my 7 physics textbooks, 3 engineering texts, or even some of my high-level math texts.

P.S. "Normal" is another word for "perpendicular"


All times are GMT -4. The time now is 12:39 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.