Dont forget the effects of the real world either. when i visit sea level with my boat it will run at 4500 rpm all day, here in the sierras it will only hit 3500. when i drive down there my vehicles are so lean and advanced for the altitude that they will rattle and diesel if i dont adjust them a little not to mention jumpy off the line. then there is humidity and temperature variables. software is good for a basis but only the real world will tell.
It doesn't have a way for you to enter any friction variables, but it has to factor something, and Vizard in a recent article said it factored loose.
You're right. It just basically assumes standard frictional losses which are more similar than you think between engines and designs. Just using wider tolerances on bearings and low friction rings will net a few hp here and there, but when you're dealing with a program that is only accurate to about 4%, the difference in friction is neglegible. I think that even if DD used a race-level of friction, it might account for 8 hp, but not 40 like we're talking about here.
Is the program using a solid roller or hydraulic roller cam? They are like night and day throughout the curve...
DD only has three choices; hyd flat, solid flat, and solid or hyd roller. Its all outlined in the owner's manual as to why and that's one of the areas where you really need to know DD to make accurate simulations.
Here's a dyno simulation. I bumped back up to 10:1, corrected some flow numbers (but those are box-stock TFS twisted wedge heads) and went with another 10 degrees on the cam. Anyone know how much lift stock twisted wedge heads will take?
Combo please. Could you give me the carb, intake, heads, cam on that motor? I just bought another cougar, 68 289 4spd, that will need a rebuild too.
