Original Post
I believe I've found the problem. I now need to make my clutch a bit better so will start a new thread Thankyou. I'm having a few problems getting my engine-wheel model working accurately. Part of the problem is not knowing quite what a real car would do in certain circumstances. The first problem is torque transfer at the clutch. A torque is applied to the engine based on the difference in rotation of the engine and drive shaft (taking differential ratio into account) and the clutch. Something like: TorqueOnEngine = (SpinShaft*DifferentialRatio - SpinEngine) * clutch * 100 clutch varies between 0 for declutch to 1, clutch up. A torque is also applied to the engine based on the engine torque at the current rpm. And this torque * clutch is also applied to the driveshaft. I know that when the clutch isn't being used this model isn't too great - the driveshaft and engine should be locked together, but my problems are mainly when moving off in 1st while the clutch is being used: Despite the high power of the engine I can't get wheelspin when the car is stopped. When it gets to about 7mph suddenly the front wheels wheelspin frantically. Also if driving up too steep a hill in 1st, when the car stops, the wheels start to spin and carry on spinning even as the car slides backwards. But when the car is stationary it seems like the clutch value has to be so low to keep the revs up that a negligable torque is passed to the driveshaft. One other question - what roughly should the inertia of the engne me modelled at? When you rev the engine before dropping into 1st, does the angular momentum of the engine cause wheelspin or just that the rpm is giving a very high torque? I currently have inertia=1 - if I go much more the engine takes ages (10s!) to rev up even in neutral! Thanks for any suggestions. [Edited by - d000hg on January 20, 2005 2:00:51 AM]