cobra marty, have you tried using the run under win 95/98 option to set the files you are loading? I have it on my desktop and laptop, both with XP, both work flawlessly.

Works on my xp. Try going to programs, Accessories, half way down menu Program compatability wizard. hop this helps

Nowonder, I have 'Performance Trends Dyno v1.1' and it is DOS based. I have been using it since '93. Just ordered from JEGS the Mr. Gasket Desktop Dyno and the updated Performance Trends v3.0. Damn new computers.

Cobra- which is better, desktop or performance?

TC- What program is it you have that also gives you boat speed & prop pitch?

I haven't used the deskktop dyno program. At the time I bought the preformance trends because the desktop didn't have S/C capabilities and I see now it does. I bought them both, one $110 and the other $40. I think that the Perf. Trends allows more detail on head flow and cam specs.

Ric232

Here is the link to the cylinder head database:

http://www.chevyhiperformance.com/in...rticleid=41598


Turbojack

I wrote the power vs. speed program myself. It uses Mercury's equations to plot the hull horsepower curve, and dyno data (real or simulated) to plot the engine horsepower curve on top of it. Changing props moves the engine curve around until it crosses the hull curve at maximum power. That's where maximum speed occurs. I would be happy to run your numbers through the program if you're interested.

Hey Tomcat, When are you going to get your power vs. speed program on a CD and offer it for ? $20. There's 6000 OSO members!

I knew someone was going to say that. The program is a messy Excel spreadsheet right now. I did make a push to get the program written in another format, but the professional programmers I spoke to wanted $$$. I would have to sell a lot of them at $20.00 just to break even. I will look into it again and see if there is a way to offer it that doesn't need so much out-of-pocket expense.

Your program, in the excel format is not too bad for us 'backyard experts'. Once you get familiar with it, playing around is easy enough. It is still a great tool even if it isn't polished. The graphs you post are very informative for those who ask. Now if I could just get it from the computer at my work to my home computer.

How is that Y trim vortec blower? I have 2- X and a T trim in the mondo case. I wonder how they compare.
Take care, Marty.

If I am not mistaken, (won't be the first) excel has where you can save a spread sheet in HTML format & it works in an web browser window. I will have to try & see if I am right. I also took the mercury formulas & made excel spreadsheet but not to the extent of yours.


I also ordered the desktop dyno. The money I paid for program may save me some money.