Anybody have a dyno program? Are the accurate? I'm trying to see what i'm going to be at hp/torque wise. I'm wondering if those programs are worth getting, as a kind of guide line. Also how do they work?

 

The ones available to the consumers aren't accurate, not enough to bother buying them. And the ones that are accurate aren't easily available, are VERY expensive, and require the input of esoteric data that most people don't understand.

Just build a combination that will perform well. Numbers themselves are completely meaningless, what matters is how the car performs in the real world.

 

tough topic ... i played around with desktop dyno for a while and it helps me understand how different components change the torque curve of an engine. However it has to be taken with a great pinch of salt
for example you can put together a 289 that will make massloads of HP at 9000rpm. however a stock 289 bottom end goes flying at 6000 (i'd guess). that's data you cannot put in there. common sense :-) it doesn't tell you squat about driveability either. you have to figure that yourself (torque curve)
when i put in a stock 289 with all it's stock components fro example the thing actually came up with a realistic max of 180HP at 5500, but when I put the data for my engine in there it comes up with 350TQ/HP and as nice as that sounds I don't think my engine is there. I'd rather guess 300 at the very very most. this causes me to think that something is wrong with the engine where there mightn't be. Car is quick enough so I stopped bothering after a while.

Anyway, when i searched for a new cam I decided for a compcams xe 268 based on the data of desktop dyno. where it starts making power and where it stops making power.
If you ask on this forum with my engine combination then probably more than 50% would come up with the same cam grind if I want one off the shelf. experience

in my opinion it's ok to figure out if a combination might go better than another, but you cannot rely on numbers.
there is software that might help experienced engine builders alright to see for exhaust scavenging or help with intake runner size decision. but that's something I don't understand well enough. and noone can guarantee that the numbers I put in are right

if you get a free copy or want to play around for the craic of it, ya. it's fun. other than that I'd rather rely on experience from others (here on the forum)

Kalli

 

nice, Thanks guys