Among the engine simulations programs I’ve experimented with, my favorite (and the most complex) is Motion Software’s Dynomation. I recently saw where Motion has updated the program now to its fifth level with estimation on flow losses based on intake and exhaust reversion. But the real key to this software is it is designed not around a simple empty and fill model but that it simulates actual wave dynamics that occur in the engine that are affected by intake and exhaust runner diameter, shape, and length. Most enthusiasts know that a shorter intake manifold runner length will tend to improve top end power at the sacrifice of low-rpm torque. While this is true, the Dynomation program allows you to custom-shape these dimensions while also working with very specific camshaft-lobe simulations. While this requires a stronger knowledge base, it also produces better results. I always tend to look at computer simulation programs as trend indicators rather than rely on them to actually predict specific engine power levels. Having said that, I also have found the Dynomation program to be more accurate than any other program I have tried. The current Dynomation 5 is a pretty good deal at the current discounted price of $399.00, but if that is more than you can handle, Motion also offers the Desktop Dyno, which is a simplified version and is priced less than $50.00. This alone is a great learning tool if you’d like to find out more about how engines respond to changes to camshafts, intakes, headers, compression, and dozens of other modifications. Think of this as an entry-level approach to learning engine technology while you have fun at the same time. You can find all these products at proracingsim.com and say hi to Larry.