Dyno Sims - Anyone used them?

[ericwevans]

I recently purchased a Dyno Simulator to tune my combination before I shell out money on parts, has anyone the board had any experience?  How close do they actually come to real world?

[plovett]

Yeah, I used to use Dynosim 2000.  It was very useful in my opinion. 

I tested the program against real world dyno data over and over and over.  That is when I had good data to input.  Specifically, I wanted actual flow numbers for the heads and true compression ratios. 

If I had good data to input, Dynosim was very accurate for peak hp.  However it almost always inflated the peak torque (and below peak) and therefore the low rpm horsepower.

So, after a while of using it and comparing it to reality, I had a pretty good idea of how to interpret a Dynosim power curve so it would match real life.  I made a spreadsheet to reduce the low rpm power to make more realistic.

Then I would input the "corrected" dyno data into my Drag 2000 program to get some fairly accurate 1/4 mile results.  That program required some tweaking, as well.

The computer I had those programs on melted down so I haven't used the dyno or drag programs for a while.

That's my experience.

paulie

[ericwevans]

I think those are the older versions of what I bought, which is DynoSim5 and DragSim5. 

[plovett]

You'll have fun with them.  Just keep comparing their results to good real world results and you will get a good feel for how accurate they are.  They are very useful programs, in my opinion, even though they aren't perfect. 

I think I remember that Dynosim was a little weird about the valve sizes, too.  You could input flow numbers with one valve size and get a result.  Then you could use the same flow numbers, change the valve size, and the result was significantly different.  That and the overoptimistic low end torque/hp are what I remember as being the most "off".

paulie

[plovett]

Oh yeah, and the intake manifold choices were pretty limited on Dynosim.  It seems like there were only 5 or 6 categories of intake manifold you could pick.  Considering the huge variety and performance differences in intake manifolds, the selection was pretty limited.   No way to input intake manifold flow numbers or anything like that.

I remember I had to pick something like "high performance street single plane"  to get results that matched real world high performance dual plane intakes like the Edelbrock RPM or Blue Thunder 1x4 bbl intakes. 

paulie

[ericwevans]

Yeah, that's the same in DynoSim5.  I think the more expensive Dynomotion5 takes manifold and exhaust into account, but it is 4x the cost of DynoSim5 so I decided I could do without.  I just got Jay's book and I was planning on running some of his combinations through it to see how they compare, but I haven't had a chance yet.

[plovett]

Jay's book would be ideal for that.  Maybe you could post how well your simulator matched his results, on the forum?

[ericwevans]

I can do that.  I'll see if I can get some done this weekend.