by 84-1074663779 » Tue Sep 14, 2004 5:15 pm
Paul, these are well presented, easy to use, complete commercial packages you just load and use.
The idea is you enter a whole lot of basic information about the engine, bore, stroke, number of cylinders, rod ratio, compression ratio, and so on. Then you tell it more about valve sizes, port flow, type of manifolding, valve timing, and a lot of other things.
It is very detailed, and it will help you to select the right inputs. Once you have built your virtual engine on the computer screen it will then do a virtual dyno run and plot power and torque. It is incredible how accurate the results are these days with this type of software. But there is far more to it than that.
For instance you can enter actual flowbench flow data into the cylinder head part of the program, and some programs let you vary intake and exhaust runner lengths as well. It will also work with alternative fuels, gasoline, methanol, nitrous oxide. Supercharged and turbocharged engines, no problem.
The beauty of it is that you can play around with different combinations, particularly valve timing. It is excellent for choosing a camshaft, for example, and it is an excellent way to learn about engines. The best way is to start out with a bog stock engine and duplicate what you know you already have on the computer. Then try out various ideas. You will quickly see that some changes have very minor effects, and other modifications can be more dramatic.
The Motion software that I mentioned is quite good, and not terribly expensive for what you get. The Performance Trends that Terry likes, is definitely better, but costs rather more.
As Terry says, the guys that wrote the software have a very deep understanding of engine theory in order to be able to make something like this work. The book that comes with the software is priceless and would be worth the cost of the software just by itself.
If you have never seen anything like this before, you are in for a real revelation.