Can I trust "desk top dyno 2000"
 

I entered ALL my engine specs, and entered all the calculations. It is saying that if retard my cam -3 I will gain 20hp up top with a increase in hp and torque across the rpm range. I have a mismatched combo because the motor is set up for a blower which I no longer have so I'm looking for everthing I can get out of it. It has dished pistons, 64cc head, and a blower cam. I have the motor out of my car now and all torn down so it would be easy to retard the cam.
I always thought that if you retard a cam you will gain up top but loose down low, and if you advance you will gain down low but loose up top? According to desk top dyno 2000 this is not the case. Should I do it and trust the program, or leave it alone?

Is the dyno program freeware? If so where did you get it? Thanks

kazza

I found that Desktop Dyno 2000 is decent in the lower numbers, but when you get into the 400+ hp range it gets inaccurate. As for retarding your cam, you might want to talk to some shops that know more about that, I do there is LOTS of power in cams though. ~Brian

Im currently in a power and performance class at UTI. my book says Advancing the cam wil increase low to mid torque and HP while retarding the cam will increase top end power. I know this is true because we built CHEVY (i had no choice) 350s and my cam was advance and all the power is in the mid range of the power band. As far as desktop dyno being accurate my teacher says its with in 2% accuracy, we even use it before we run our engines, as long as the information you entered is correct to your engine it will be close.

After reading this thread I just downloaded deskot dyno 2000 off kazaa. I was playing around with it a little and I entered in my buddies old 306 combo. I dont know if someone added it in later or not but it when I downloaded it, i also got a bunch of cam files and flow files. My friend had out of the box tfs tw heads, a vic jr, a 650 holley, 10.1:1 comp, and the comp xe282 can. I put all that stuff in and n/a it throws out over 450hp and about 400 ft/lbs torque. I know for a fact he got 340 to the wheels on the dyno with the car. Are there other things involved with the program. I noticed it doesnt ask about what kind of intake, only if its single or dual plane.

you guys are missing some of the parts of this program sound like. I bought the program and it does ask single or dual plane if you select carbureted wrather than efi or turbo/supercharger. NotchJohnson your seeing flywheel HP and torque with this program. It doesnt know wether your using a stick or auto trans so it cant figure drive train lose, hence the reason your friend is seeing 340 at the wheels if he put the engine on an engine dyno hed see the 400. My version only has 2 or 3 cam files , big block ski boat, stock and i think 4 valve. There is another program where you can take the engine you "built" and put it into a car and see what it would potentially do. Desktop dragrace i beleive its called. hope this helps

Yeah he was running a carb, thats why I clicked dual plane. I knew the hp was at the flywheel, but doesnt 450 seem high still? He is getting 340 at the wheels, so it dropped 110hp? I dont know its not really that big of a deal. Also, mine did come with a hell of alot of files. There is like every comp cam, fms and tfs cams, ect, as well as a bunch of heads, if you want me to send the files to you i will, just let me know. - John

i just downloaded desktop dyno 2000 off of kazza and i cant get the darn thing to open, it keeps asking me what program i want to open it under, and every one that i try tells me that i cant open it there. does anyone know where i have to open this to. or did i do something wrong. its in my documents and downloads folders. i just cant get it to work????????

The one I downloaded needed to be unzipped, and then it worked fine.

i unzipped it but it still doesnt work

The problem with KAZAA is there's no quaility control... alot of times you download stuff and it isnt even what it said it was... you might have a bad package.. just download it again... some are self extracting zips others are standard zips... mine didnt come with any cam files or anything but it worked...

-as

Mine has all the cam files, heads, etc... I can also enter my own head specs from my flow sheet, and my exact cam profile down to the exact degree that the valves start to open and close.
Lethal5Oh, I understand what you are saying about advancing and retarding the cam. I'm just saying that it is strange that it gave me a increase every where and can I trust it?

With last year's motor, DD2000 provided near perfect correlation to what we measured on the engine dyno. The TQ and HP curves were right on, including the peaks, and values were within 3%. Gives me good confidence going into this season with a completely different motor combination. Let me say this though, just like with any other engineering computer program => JUNK IN = JUNK OUT! There are nuances to the program. Read the entire user's manual two or three times over. It has a lot of good information on the assumptions that go into the programming.

FYI: Last year's motor made 465hp/424ft-lbs so I don't go for the 'up to 400hp' comment. At that point, the user was probably choosing some wrong components or assumptions.

I'm just throwing out my opinion, but doesn't the program simulate an engine dyno? How could this really be compared to a chassis dyno? I think this is why some people that have had there car dyno'd might see numbers real close or some real far off. Not every car has the same HP/TQ loss through the drivetrain. I've notice with the program when using an EFI intake option you really have to play with the CFM numbers. Motion Software really needs to put different intake options on the EFI (i.e. Street, Track or Race runner length). The Carb. option is pretty close with Duel, Single, Tunnel Ram.

Murdock

Thanks guys! I think I am going to give it a try and retard the cam -3. Time to knock the dust off the old degree wheel again:)

i put all my info in, exactly how it really is, and it told me that if i retard my cam 4 degrees ill pick up 36hp at peak.
the only thing that i cant figure out is my cam info, i think i need to make my own cam profile but how do i do that. i can do the lift and duration, but none of the specifics?

On the top left there is a few more options you can do. One of them is "cam math" hit that and enter in all the values.

GIGO is GARBAGE in GARBAGE out.

Sorry, I'm a Systems Engineer! (aka computer geek):D