I dont understand what Ivo,Ivs,Evo,evc?

 

Those are for Intake valve opening, closing, exhaust valve opening, closing, etc. Standard cam specs don't give you full info on the cam. I think it can interpolate the ramp rates from the ivo, ivc, evo, evc. You can usually get the info from the cam manufacturers, I think. Been a while since I messed with DD2000.

 

The best help I can give you is advice...... Throw it in the trash.

Fun to play with to get a basic idea of certain cause and effects. Problem is they never match the real world.

Your best is input from this list and those whom have real world experience.

Seriously....... Hot rod magazine in a recent article pointed out one of the most common mistakes by beginners is to not use proven combinations. They cited an example of mildly tweaking a proven combo with a few small things that sounded like it would work better…… the lost 100 hp over the proven combo.

Have fun….. just don’t believe a damn bit of what dyno 2000 says.

 

DTD is great..Its teh people using it that give the problems..If you read the on CD manual then you will get the gist that im talking about..Large tube headers are modeled after prostock 2 1/2" tubes not your Grott longtubes or dynatechs...

Get the cam card to input cam info and flow sheets and know the compression and you will be within 10HP..

 

Boy

I don't know what to tell ya......? Guess it could be driver’s error. However….

I've honestly got over 500 dyno pulls tuning and testing different stuff, flow sheets on three sets of heads and about a half a dozen custom ground cam cards not counting over the counter cams like two Xtreme cams, (224/230, 224/236) LPE 211/219 or the 306 cam I've owned.

No way in hell did the $19.95 desktop dyno match the results of actual dyno testing.

Like I picked up 2-3 hp by removing the MAF screen. Find that trick in the software.

I also own Performance Trends software and it is better, but absolutely, positively no substitute to actual dyno testing.

Uuuuuuuuuuuuu!!! The thought even of setting up a real LT1 combo on desk top dyno. I’d need a little more proof in the errors of my ways to make a believer out of me. How about I provide the spec’s on a 396 combo I’ve owned and you tell me what DTD says it makes. I then scan the real dyno sheet, cam card and flow report to keep everyone honest. How about we change cams and see how it comes out? (again……. Compared to the actual dyno sheet)

 

Possibly drivers error..Myself have had every engine ive built on an engine dyno..Keep the same record if not more detailed with unneeded info but the last 3 engines ive built came within 10 HP..You must remeber that it doesnt take into account for the temp humidity and so forth..Remember on the box its states that its a sim program not a replacement for the dyno..Many people here wont spend $400 on a dyno rental for teh day nor have the ability to do such..So the sim is the next best alternative..

Last year inorder to validate my 18* 406 and prove that i didnt need to run my canted valve brodix heads i spent weeks toying with DTD..I came within 8 HP of my actual final tune..Provided that was after the carb was perfect and teh timing curve was dead on.

After a quick teardown and some looser clearances here there and everywhere My LT1 combo came over 26HP more than DTD stated..The SFI setup assumes the proper TB sizing runner sizing and plenum volume..If those are off you should resort to running teh sim with a more restrictive intake setup..Little things like that is what makes the program something to use as a reference..The word optimum is something that 99% of gearheads dont wont to understand..

 

For N/A applications, it's OK.

For blowers...forget it.

FWIW, I've been messing w/ Engine Analyzer from Performance Trends. Very nice program.