I have my setup dialed in the program and the numbers seem high... I guess Id just like to know if its accurate to help me decided what mods my college kid budget can afford.

Thanks

 

I put all my info into it and it came out about 25-30 HP higher than what I actually dynoed at.

 

most peopel say it is usually with in about 2% of actual crank hp and torque numbers for N/A motors.

later
tim

 

it says a ZZ4 cammed and vortec headed 305 with 9.3 compression ratio has 377 crank HP - seems kinda high to me.

 

Yeah, I have the program and to me the numbers always seem a little too optimistic.

 

Anyone want to burn me a copy of this program?

 

Download it off Kazaa

 

Mmm we shouldn't be promoting pirated software. It is illegal.

Desktop Dyno seems very optimistic when it comes to hp levels. Remember the program is only as smart as the people who developed it.

 

hey, just passing along the reply someone else gave in a similar thread.

 

Haha, we should be buying products like we used to; has anyone seen the stock market nowadays?

 

If it's set up correctly it's acturally very accurate.

With certian combinations of parts, i've actually had tne numbers come up low on it.

Set it up "conservatively" and it's pretty accurate.

When using hydraulic roller cams, they should be entered as hydraulic flat tappet cams, unless it's a "race cam".

be Realistic with the exhaust, CR and it is generally pretty darn close.

I don't know exactly what you'd enter the tbi under, whether under the 4bbl carb setting or the 2bbl carb setting.

I've manipulated it pretty acurartely for a while, jsut takes pracitce, and some "real" dyno numbers to compare it against

 

I just set up the tbi as 455 cfm @ 3.00 inHg, cr I used 9.5:1, hydro flat tappet, and short tube headers with mufflers.

The thing I cant figure out on the cam is the duration. Im trying to set it @ .050 with 206/208 but it gives me a lot of negaitve numbers, and all the other cams seem to be a long longer duration. The ZZ3 cam is listed as like 270 duration and really its only like 210 isnt it?

 

Using the cam durations confuses me too. The ZZ4 cam has an advertised duration of 275/280 and a .05 duration of 208/221. Shouldn’t they give the same results, but desk top dyno shows the two to be way different. Also lift seems to have no effect, there is almost no change in a cam with say .400" and the same cam with .550".