Desktop Dyno

[RR3834bbl]

Is there anyone using good desktop dyno software? Does anyone have info as to computer dyno estimation vs. actual engine dyno numbers in their experience? I’m wondering if a good desktop dyno program is worth my time and if so, which one

[65TerrorCuda]

I have heard the Mr. Gasket dyno is optimistic, but I still use it. It will give you an idea of what changes in cam, carburetion, compression, etc. will help and what will hurt power, at least in desktop dyno world. Before I do any major changes to my engine setup, I'll run it through the computer and see if it's worthwhile to advance the cam, for example. It's by no means cutting edge software, but it's fun to build up a motor and dyno it in less than 5 minutes. Maybe that 6-71 blown 318 with small port heads really will blow the tires off for days, it's not hard to find out. Search on limewire, it's worth your while.

[Chargerguy1968]

I too use the Mr. Gasket Desktop Dyno. It is a bit optimistic, but it is good for the average car guy. Like 65T, I use it to see how changing things to the engine will effect it. Also, I like to see the graphs, where the power comes in, tourqe curves....etc. There are some dyno-sym software that is very accurate, but also expensive.

[krazykuda]

I use Desktop Dyno and Performance Trends Dyno. As stated above Desktop is a bit optimistic and also simpler to use (however it does not have Hemi data(my 2000 version at least)).

The Performance Trends is more complicated (and expensive), however the results are more realistic. It also gives you a summary of your setup and makes recommended changes to help you optimize your setup. There are other programs available with it that you can download your setup into them and predict your et's. He can predict within a couple of tenths, but you have to put in accurate info. Like the old saying about computers...garbage in, garbage out. The guy that recommended it to me swears by it and has used it to have camshafts custom ground with good success on the strip. It has alot of pop up recommendations to help beginners that you can turn off once you get the hang of it. It gives much more information like brake specific fuel consumption, spark knock, etc. it even has an optimization portion that you can use to try and compare different cam details like centerline, lobe centers, valve open/close with immediate feedback. You can print graphs with any of the roughly thirty or so output information, torque/horsepower, cam profile. The recommendations also help you balance the intake and exhaust systems for proper balance.

I don't know about you guys, but I have run the opimization program on the desktop dyno and my baseline was better than the "optimized" results. It is good for a basic general comparison. It is good for the average guy, quick and not very complicated to learn.

Performance trends has many different levels depending on how much cash you are willing to spend. I went for the mid range which is reasonable. I like to compare on both programs (compare twice, build once...).

It just depends on how much time and money you are willing to put into it.

[HankL]

I agree with krazykuda
that the Performance Trends Engine Analyzer 3.2 software is much better than the cheaper Desktop Dyno.

Kevin is an ex-Ford engineer
and if you look over his website
he is a 'hands on' guy that builds many products
such as his own custom wide range O2 sensors
and several flow bench devices.

Reviews of dyno estimation computer programs:

http://www.babcox.com/editorial/ar/ar110047.htm

The guys behind the Megasquirt project beginings
have made another type of dyno available to engine testers
for free:

http://www.bgsoflex.com/dyno.html

a commercial on the vehicle dyno estimator:

http://www.bahntech.com/products/Auto_Dyno/dyno.asp

[RR3834bbl]

Thanks all for the info about dyno software. Krazykuda, I checked out Performance Trends on-line and downloaded a demo version of Engine Analyzer v3.2, and Trans Gear Calculator v2.0. I liked the engine program because it has plenty of Mopar engine data preloaded. The gear calculator is helpful in finding your engine speed at each transmission gear selection based off of your wheel size, tire size, and final drive ratio. I liked the looks of the Engine program well enough, so I ordered it. You were right, the price is kind of steep, but proved to be worth it.

I was amazed at how close the Engine Analyzer is at estimating torque and horsepower. Before I tried anything I first established a baseline by using published engine dyno numbers from a 2003 Mopar Muscle Engine Tech Guide. In this tech guide Steve Dulcich takes 340, 383, and 440 engines and first builds them to stock specs. He puts them on the engine dyno and shows the results. Then Mr. Dulcich step by step adds aftermarket engine components publishing the dyno result of each upgrade.

Anyway, to make the long story short, I put the engine data into the Engine Analyzer program to closely match the engine build to see how close those numbers were to the actual published engine dyno numbers. The results; within two horsepower and ten foot pounds of torque, and all at the same power band... amazing!!! One important part I found about entering the engine data to match a published engine dyno number is that you select the production water pump only as this is the only engine accessory used when dynoing an engine. No alternator, no power steering, no A/C. That makes a huge difference. The second thing is that most engine dynamometer testing is done with open exhaust or close to. Only when I made those selections is when I got the close numbers.

Then for kicks I added the 60s production engine accessories and a sporty production exhaust system. This took away 32 brake horsepower right off the bat. Then I multiplied that number by the old rear wheel horsepower formula: Brake Horsepower multiplied by 0.80 equals rear wheel horsepower. This gave me a number that is close to published numbers I found in a Mopar Muscle magazine in which Chassis dyno testing was done on various Mopars of various builds.

So although the program is not 100% dead on, it may be safe to say that it gets you there to within at least plus or minus 5% providing you are putting in the data correctly and covering all your bases. What a great and fun tool to have!

[HankL]

I can tell you from personal experience
that the EA 3.2 can come within 0-5 hp and torque
at nearly every point on the curves
on the
Magnum 5.2/5.9 V8s
and 5.7 Hemi .

To get this close
you need to work with all the EA 3.2 data entry boxes
a little at a time
and the good thing is
this 'tweaking' tells you more about
how the engine design really works.