level 1
笨理合计 发动机转数高 传动带来的力道越大 扭矩应该越大啊
2012年11月23日 04点11分
level 11
按公式计算：马力=（转数×扭矩）÷5252，也就是说：扭矩=（马力×5252）÷转数
因此转数越高，扭矩越小
2012年11月23日 10点11分
3
因此转数越高，扭矩越小
![[钱]](/static/emoticons/u94b1.png)
专业玩车的就是不一样啊
level 7
Yahoo Answer的专业回答：http://answers.yahoo.com/question/index?qid=20081107064818AAVfQMG
Because cam shafts have a limited RPM range where they are efficient. On a stock street engine it is a compromise. The manufacturers grind the camshafts so they are more efficient at a lower RPM range. This is because they want the engines to deliver more power at a low RPM. This saves fuel and makes the engine last longer. They also want to develop more power at a usable RPM range for every day driving. It would get annoying very quickly crusing down the highway at 65 MPH with the engine turning 7000 RPM so making the most power at this RPM doesn't make sense. People would rather have the engine purring at 1800 RPM at 65 MPH instead.
With a Rotary engine, the location of the ports are the equivalent of the piston engine camshaft. Again, they want the engine to develop more power and torque at a lower RPM and to conserve fuel and make the engine last longer. In the stock street versions of these engines, at high RPM they are reaching the limits of how much air can pass through the intake ports.
Race engines develop their power at a high RPM. With these engines, power and torque are everything. The professionals rebuild them after every event so they are only concerned with the engines lasting until the end of the race. Some professional dragster and funny car teams rebuild their engine after every 1/4 mile pass.
2013年03月06日 06点03分
6
Because cam shafts have a limited RPM range where they are efficient. On a stock street engine it is a compromise. The manufacturers grind the camshafts so they are more efficient at a lower RPM range. This is because they want the engines to deliver more power at a low RPM. This saves fuel and makes the engine last longer. They also want to develop more power at a usable RPM range for every day driving. It would get annoying very quickly crusing down the highway at 65 MPH with the engine turning 7000 RPM so making the most power at this RPM doesn't make sense. People would rather have the engine purring at 1800 RPM at 65 MPH instead.
With a Rotary engine, the location of the ports are the equivalent of the piston engine camshaft. Again, they want the engine to develop more power and torque at a lower RPM and to conserve fuel and make the engine last longer. In the stock street versions of these engines, at high RPM they are reaching the limits of how much air can pass through the intake ports.
Race engines develop their power at a high RPM. With these engines, power and torque are everything. The professionals rebuild them after every event so they are only concerned with the engines lasting until the end of the race. Some professional dragster and funny car teams rebuild their engine after every 1/4 mile pass.
level 7
翻译：
这是因为往复式内燃机的凸轮轴（camshafts）只能在某一转速（RPM）范围内最有效率。原厂家用引擎在这种取舍上一般选择把凸轮轴设计成在低转速下最有效率。这样低转高扭矩，引擎开起来就有一种“有劲”的感觉。这样做还可以避免引擎必须要拉高转速才能输出大扭矩的情况，而这种情况既费油又损耗引擎的寿命。此外，凸轮轴在低转速下最有效率的设计使得巡航时引擎保持低转速。高速上65英里/时巡航时如果引擎必须在7000rpm下咆哮这是很烦人的，而1800rpm下巡航就可以接受。
家用车的转子内燃机的扭矩受气埠（ports）的制约。出于同样的降低引擎转速的考虑，气埠一般也设计成低转高扭矩，而高转扭矩降低。
赛车引擎总是在高转速下运行，而且需要提供尽可能高的功率和扭矩。另外一具赛车引擎一般只用于一次比赛，所以不存在挑战极佳耐久性的问题。因此，赛车引擎一般设计成高转下功率和转速达到峰值。
2013年03月06日 06点03分
7
这是因为往复式内燃机的凸轮轴（camshafts）只能在某一转速（RPM）范围内最有效率。原厂家用引擎在这种取舍上一般选择把凸轮轴设计成在低转速下最有效率。这样低转高扭矩，引擎开起来就有一种“有劲”的感觉。这样做还可以避免引擎必须要拉高转速才能输出大扭矩的情况，而这种情况既费油又损耗引擎的寿命。此外，凸轮轴在低转速下最有效率的设计使得巡航时引擎保持低转速。高速上65英里/时巡航时如果引擎必须在7000rpm下咆哮这是很烦人的，而1800rpm下巡航就可以接受。
家用车的转子内燃机的扭矩受气埠（ports）的制约。出于同样的降低引擎转速的考虑，气埠一般也设计成低转高扭矩，而高转扭矩降低。
赛车引擎总是在高转速下运行，而且需要提供尽可能高的功率和扭矩。另外一具赛车引擎一般只用于一次比赛，所以不存在挑战极佳耐久性的问题。因此，赛车引擎一般设计成高转下功率和转速达到峰值。