Is this program at all accurate (I know it isn't exact but can it be used to determine anything useful)? Has anyone had similar results (as determined by DD2000) vs. what an actual dynometer reads?

I'm not sure why the program has completely different dyno graphs for
@.50 durations vs. advertised? (this is using online cam cards provided by crane for its cams)

According to DD2000 have a small @.50 intake duration coupled with a huge exhaust duration equals great topend with much better bottom end. The split is ridiculous though and how it would perform in the real world Good for a turbo I guess. any thoughts?

 

Would not be my first choice for an engine program, but fun to play with if you dont want to pay for the good stuff.

What are the flow parameters on the heads you have in the program??

 

I modeled a chevy 434ci engine using desktop dyno and it was 5hp and about 7ft lbs off from the actual dyno numbers. Accuracy depends on your ability to enter accurate information. Correct cam, and head airflow go along way.

 

Agreed. The head flow numbers were posted by Lloyd for the 561 castings a while back and the exhaust is stock head flow with pipe. If someone has a headflow file for the 561 castings that they know is accurate I would like to try it compared to mine.

I also imported the older head flow data into the program and there was not too much difference between the two as far as the curve. Older heads seemed to peak higher.

I have seen posts where people are using 750cfm as the intake manifold flow but according to a dlowdatabase I have for LTX heads the flow as done by TPIS is 409cfm? (no other info on how it was tested though)

Also what intake are ya'll using? I picked sequential but the torque seems to fall off rather quickly with this intake selection. Tried all the others not sure which one will give me better results as per stock manifold??

 

So peak numbers were close but how did the hp/tq curves compare?