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| Blu Falc |
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READ THE POST
the empisis is on torque because power is made from torque. torque does not drop of as rpm rises exept in an electric motor. If you have a look at a dyno for 'most' engines the torque will continue to rise with rpm untill the engine is not longer breathing properly. This is where cams, induction length, variable intake manifold, extractors ect all come into play to decide the torque band which decides the power band. |
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| stockstandard |
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FPV_GTp wrote: stockstandard wrote: One other interesting point that can be made about drag racing... Notice how in my post above when the physics teacher said that torque is good for the start of a 1/4 and power is good for the rest, he added that this assumes the tires were hooking up. By saying this he avoided some of the other complexities of drag racing. A 1/4 mile pass can be broken down into two parts - the traction limited part at the start, and the power limited portion that follows. In my car for example, I cant apply all the engines torque of the line because I will just spin the wheels and go nowhere - I am traction limited. If I further increase low end torque without increasing traction, I will go no faster because I will have to use less throttle so I get off the line cleanly. Instead, if I leave the engine alone and increase traction with some fatter rubber or an LSD, I can reduce the traction limited portion of my 1/4 run, and my ET will drop. Its all pretty obvious when you think about it, but it helps you picture how all the parts of the car have to work together to get you down the end fast. hi just thought i would throw my two bobs worth in this convo sorry if i missed something earlier cause i havent read the whole posting but the the emphasis is all on torque ?????? remember one thing torque drops of as engine speed (RPM ) increase ??? WHY  ???now my little question since we on about drag racing and so forth is do u change gears down the quarter mile at max torque ??? or do you change gears at max horsepower??? and when your in top gear what should you be crossing the line at max torque or max horsepower ??? just my few questions and im sure someone from St Albans can answer the question PMSFL cya Its all about power. Go back and read it some more (or at lest from page 5 onwards).
_________________ Stoke me a clipper, I'll be back for Christmas |
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| FPV_GTp |
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Blu Falc wrote: READ THE POST
the empisis is on torque because power is made from torque. torque does not drop of as rpm rises exept in an electric motor. If you have a look at a dyno for 'most' engines the torque will continue to rise with rpm untill the engine is not longer breathing properly. This is where cams, induction length, variable intake manifold, extractors ect all come into play to decide the torque band which decides the power band. LOL mmmmmmmmm maybe i should read the post hahahaha lol torque does drop of maybe you should have a look at some dyno graphs LOL you answered one of the question i asked but the rest i think you have it wrong LOL, at higher rpm cylinder fill starts to diminish so torque does drop of LOL
cya
_________________ WANTED - Complete BTr4 and zf 6hp26 automatic transmission 6 cylinder and V8 transmission(s) suit rebuild? Drop me a PM if you can help would be greatly appreciated - thanks Last edited by FPV_GTp on Mon Jul 25, 2005 8:40 pm, edited 1 time in total. |
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| FPV_GTp |
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stockstandard wrote: FPV_GTp wrote: stockstandard wrote: One other interesting point that can be made about drag racing... Notice how in my post above when the physics teacher said that torque is good for the start of a 1/4 and power is good for the rest, he added that this assumes the tires were hooking up. By saying this he avoided some of the other complexities of drag racing. A 1/4 mile pass can be broken down into two parts - the traction limited part at the start, and the power limited portion that follows. In my car for example, I cant apply all the engines torque of the line because I will just spin the wheels and go nowhere - I am traction limited. If I further increase low end torque without increasing traction, I will go no faster because I will have to use less throttle so I get off the line cleanly. Instead, if I leave the engine alone and increase traction with some fatter rubber or an LSD, I can reduce the traction limited portion of my 1/4 run, and my ET will drop. Its all pretty obvious when you think about it, but it helps you picture how all the parts of the car have to work together to get you down the end fast. hi just thought i would throw my two bobs worth in this convo sorry if i missed something earlier cause i havent read the whole posting but the the emphasis is all on torque ?????? remember one thing torque drops of as engine speed (RPM ) increase ??? WHY ???now my little question since we on about drag racing and so forth is do u change gears down the quarter mile at max torque ??? or do you change gears at max horsepower??? and when your in top gear what should you be crossing the line at max torque or max horsepower ??? just my few questions and im sure someone from St Albans can answer the question PMSFL cya Its all about power. Go back and read it some more (or at lest from page 5 onwards). LOL i have read it all LOL
and i know where my money s on LOL POWER for the people
cya
_________________ WANTED - Complete BTr4 and zf 6hp26 automatic transmission 6 cylinder and V8 transmission(s) suit rebuild? Drop me a PM if you can help would be greatly appreciated - thanks |
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| stockstandard |
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torque drops off (slowly) with rpm.
Mine makes about 310nm @ 3600 301nm @ 4000 276nm @ 5000 ...
_________________ Stoke me a clipper, I'll be back for Christmas |
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| FPV_GTp |
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stockstandard wrote: torque drops off (slowly) with rpm.
Mine makes about 310nm @ 3600 301nm @ 4000 276nm @ 5000 ... thank you now do you have the Bhp figures saves me not having to calculate them and do you have figures for T,RPM,Bhp for higher rpm just to see what happens at higher up
now im going way of track here
what motor produces max torque at nearly zero revs????? cya
_________________ WANTED - Complete BTr4 and zf 6hp26 automatic transmission 6 cylinder and V8 transmission(s) suit rebuild? Drop me a PM if you can help would be greatly appreciated - thanks Last edited by FPV_GTp on Mon Jul 25, 2005 8:51 pm, edited 2 times in total. |
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| jonbays |
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FPV_GTp wrote: stockstandard wrote: torque drops off (slowly) with rpm. Mine makes about 310nm @ 3600 301nm @ 4000 276nm @ 5000 ... thank you now do you have the Bhp figures saves me not having to calculate them and do you have figures for T,RPM,Bhp for higher rpm just to see what happens at higher upnow im going way of track here what motor produces max torque at nearly at zero revs????? cya An electric motor! |
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| unclewoja |
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FPV_GTp wrote: LOL
mmmmmmmmm maybe i should read the post hahahaha lol torque does drop of maybe you should have a look at some dyno graphs LOL you answered one of the question i asked but the rest i think you have it wrong LOL, at higher rpm cylinder fill starts to diminish so torque does drop of LOLcya Your statement clearly states that torque is maximum @ zero revs. You say that torque decreases with rpm? If that's so, and torque ALWAYS gets lower with an increase in RPM, how does it RISE to PEAK torque in the first place? It would be more correct to say that cylinder fill drops off after peak torque is achieved and even then, that's not completely true. There are plently of engines out there with two peak torque figures because of the cam and intake characteristics. So on these engines, torque drops off with rpm after the first peak torque, then starts to rise, shock horror, till it hits the second peak torque figure. I can't believe that so many people are incapable of understanding stockstandard's initial post. I can see there are a lot of people here whom I would not be at all surprised to see driving a car with either a 2.9 diff and 4000-7000 RPM cam, or a 3.9 diff and a 1000-3000 rpm cam |
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| flyingnunrt |
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I don't profess to know much about HP v Torque but there are still a few unanswered questions.
Power = work done in a given time To do the same amount of work in less time you need more POWER To make more power given an amount of torque you have to increase the revs, OR at a specific RPM you have to increase the torque available, regardless of engine characteristics. In Waggins Real world example He probbably spun the wheels a bit more off the line with the XR8 and the aerodynamics probably slowed the I6 at the finish.
_________________ As Sigfried once said "Nein Nein Ninty Nine" |
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| xcabbi |
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[quote="FPV_GTp]
now my little question since we on about drag racing and so forth is do u change gears down the quarter mile at max torque ??? or do you change gears at max horsepower??? and when your in top gear what should you be crossing the line at max torque or max horsepower ??? cya[/quote] Ideally you would change gears at max power. And have the gearing set so that when you change gears the revs fall to the peak torque rpm. That is the quickest way to accelerate. |
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| Blu Falc |
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FPV_GTp wrote: Blu Falc wrote: READ THE POST the empisis is on torque because power is made from torque. torque does not drop of as rpm rises exept in an electric motor. If you have a look at a dyno for 'most' engines the torque will continue to rise with rpm untill the engine is not longer breathing properly. This is where cams, induction length, variable intake manifold, extractors ect all come into play to decide the torque band which decides the power band. LOL mmmmmmmmm maybe i should read the post hahahaha lol torque does drop of maybe you should have a look at some dyno graphs LOL you answered one of the question i asked but the rest i think you have it wrong LOL, at higher rpm cylinder fill starts to diminish so torque does drop of LOLcya I have seen many dyno graphs, the torque builds then drops off after the engine is being restricted for whatever reason ie it has passed the efficiency of the cam or the intake is creating restriction ect. |
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| FPV_GTp |
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unclewoja wrote: FPV_GTp wrote: LOL mmmmmmmmm maybe i should read the post hahahaha lol torque does drop of maybe you should have a look at some dyno graphs LOL you answered one of the question i asked but the rest i think you have it wrong LOL, at higher rpm cylinder fill starts to diminish so torque does drop of LOLcya Your statement clearly states that torque is maximum @ zero revs. You say that torque decreases with rpm? If that's so, and torque ALWAYS gets lower with an increase in RPM, how does it RISE to PEAK torque in the first place? It would be more correct to say that cylinder fill drops off after peak torque is achieved and even then, that's not completely true. There are plently of engines out there with two peak torque figures because of the cam and intake characteristics. So on these engines, torque drops off with rpm after the first peak torque, then starts to rise, shock horror, till it hits the second peak torque figure. I can't believe that so many people are incapable of understanding stockstandard's initial post. I can see there are a lot of people here whom I would not be at all surprised to see driving a car with either a 2.9 diff and 4000-7000 RPM cam, or a 3.9 diff and a 1000-3000 rpm cam lol read what i wrote yes max torque @ nearly zero revs steam engine i just throw this into the convo just a brain teaser but never mind i think you saying im contradicting myself
on a internal combution engine cylinder fill does fall of at higher
RPM
cya
_________________ WANTED - Complete BTr4 and zf 6hp26 automatic transmission 6 cylinder and V8 transmission(s) suit rebuild? Drop me a PM if you can help would be greatly appreciated - thanks |
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| Blu Falc |
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a cam can make the engine fill increase with rpm up to a certain point by having long duration and lift and uses the inertia of the intake air and fuel to keep filling the cylinder even when the piston is moving up, obviously not too far up.
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