[Desktop Dyno Engine Simulator Free Download
Oludare Padilla
At present, we are up to version 5 of the engine modelling software, with version 6 in the works. With a decade and a half of refinement, DynoSim5 has become a valuable tool in the arsenal of both high-end performance enthusiasts and engine builders alike.
By allowing testing of a wide range of components and specifications, without buying a single component or turning a single wrench, the engine simulation software allows you to save money and dyno time by being able to concentrate only on the areas which have shown promise in the simulation.
To that end, in this article, we are going to take an in-depth look at the software and its features, then model two real-world engines and compare their performances on the dyno to their simulated performances in the program.
Conversely, other software relies strictly on calculations to determine volumetric efficiency alone, and then estimates horsepower and torque from that. Per the DynoSim5 manual, the DynoSim software performs several million calculations at each 500-rpm test point, with 41 test points calculated in a full power curve simulation.
In the Short Block menu, there are a number of predefined short-blocks to make your life easier, where the bore, stroke, rod ratio, and number of cylinders are all preselected. Alternatively, you can choose to enter your own bore and stroke dimensions, and when it comes to the connecting rod, you can either select a rod ratio, or a specific center-to-center rod length, and the ratio will be calculated for you.
When it comes to the Combustion Chamber geometry selection, there are nine different options to choose from, with a handy picture menu to help you choose the correct chamber shape for your cylinder head. With all the information entered, the program can then estimate the optimum ignition timing for the combination, or conversely, you can enter your own timing curve and see how it varies.
Next, and potentially more complex, is the Forced Induction section. There are options for positive-displacement superchargers, centrifugal superchargers, or turbochargers, with a large selection of pre-modeled options of each. You can customize those models, or create your own, with setting your wastegate actuation pressures, pulley ratios, turbine size, and turbine A/R ratio. Additionally, you can add, remove, and adjust intercoolers in the system.
The second-to-last section covers the exhaust, which is everything downstream of the exhaust port. Options include: stock manifolds, high-performance manifolds, small-tube headers, large-tube headers, and large-tube stepped racing headers, with or without mufflers and/or catalytic converters attached.
The final, and probably most important and useful category is the Camshaft category. There are pre-defined generic grinds available, as well as actual Comp Cams part numbers in a library. In addition to the 799 camshaft files contained in the DynoSim5 software, an expansion called CamDisk8 with an additional 6,000 camshaft files is available. There is also the ability to enter the cam card data from any cam you can get the information for, or dream up. Additionally, there is a provision for Variable Valve Timing camshaft profiles.
The CamManager is probably one of the coolest and most powerful tools in the program. You are able to select camshafts from a library, enter specs from a cam card, or enter your own specs, and see how each spec change alters the profile.
The camshaft timing optimizer is where the processor power of your PC is really tested. It will generate camshaft specifications based on a given valve lift, which is optimized for one of four areas: Peak Torque, Area under Torque Curve, Peak Horsepower, and Area under Horsepower Curve.
Following the same process for the LS3, using the LS3 build article as a guide, we started off with the short-block category. The LS3 actually maintains stock displacement using an LSA forged crank with a 3.622-inch stroke, and Mahle pistons in the stock 4.065-inch bore, for 376 cubic inches or 6.136 liters (commonly rounded to 6.2-liter). The Lunati rods measure 6.125 inches, center to center.
The cylinder heads used in the build are factory-ported Chevrolet Performance LS3 units. Since we have actual flowbench data for the heads, we were able to plug that data into the program directly, along with the 2.165-inch intake and 1.590-inch exhaust valve sizes.
For this fictional showdown, we are going to more or less use the rules from the original LS3-Coyote Shootout, but with a few additional restrictions. For displacement, we want both engines to be as close to 5.0-liters as reasonably possible. Both engines will run unmodified OEM cylinder heads, and even though this is all hypothetical, we want to keep these engines in the realm of real world capability.
For the most part, the Coyote engine from the actual shootout is a solid build, but we need to make a few theoretical improvements. First, to be addressed is the bore. By adding .020 inches over OEM, for a 3.649-inch bore size, we not only make for a perfectly square bore and stroke, but come out to 305.3 cubic inches, or 5.003 liters.
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