Anyone Know of Online Engine Dyno Software so I Can Test a Few Combos?
I don't know about WAY off, the prediction is as good as the data you giveut it.
X2.
I use Desktop Dyno 2K all the time. I downloaded it for free from a file sharing server.
I try to gather as much info as I can, especially realistic flow numbers. It's really just a general guess until you have the right data and head flow numbers are the key along with compression data. Shady Dell is a good place to start, they publish all sorts of flow numbers. So does Hughes Engines. Guys put up stuff on Moparts a lot too. Once it's all plugged in correctly, it can be a pretty cool tool. I feel like it's fairly accurate, like within a few percentage points as long as all things are input correctly.
There are a few discrepancies, like manifold type is pretty cut and dry, there's really no tweaking that particular field. For example, I used Dulcich's Cheap As Dirt 318 as an example and came pretty close to his numbers but only when I changed to a single plane intake even though he was using an Air Gap. Exhaust also has no variability for size or type.
Going further, once you have a HP number for your combo and you happen to know your car's weight, you can subtract 17 or so % from the final flywheel HP number to get RWHP. Then you use the Wallace racing or TCI online calculators and guess quarter miles times and MPH fairly accurately.
