tomcat

I know you can save the program as HTML in Excel, but the problem is you can't lock the cell formulas. I tried this with a buddy and he made a few wrong clicks and wiped out a few formulas...then you're screwed. I think maybe saving it on a 3.5" disk with the formulas locked is better, but then the user has to have Microsoft Excel and know how to use it.

Visual basic looks better but getting the graph to work is a problem(?) The best approach seemed to be a Java calculator. They don't need to run off a server, they run client side on your computer, after you get to the web page with the calculator. These are the guys who wanted $$$. Maybe something similar could be put on a disk, not a web page. I really don't know much about programming as you can tell.

Hey Turbojack, I love Desktop Dyno, but it doesn't save money; it encourages you to spend more!!

Ric232

I just received my copy of Dyno 2000. I like it so far. I've managed to create some pretty accurate simulations for 454/502 Mag MPI motors.

What I need, however, are the the intake flow figures for the MPI intake. I assumed 600 cfm and it worked well.

Does anyone know the real flow numbers? How about for an HP500 EFI and the HP500 carb?

Thanks.

Turbojack

Finally got my program & started to play with last night. There are two areas I am not sure on. When putting in head flow numbers I am not sure what I should use at pressure drop. On the web address that TC gave I do not see what pressure drop they used. In looking at what program has I see them using anything from 28-21.

Second question I am not sure what number to use for a stage 4 procharger. I am guessing that procharger is not giving out their specs so that is why they are not listed.

tomcat

Turbojack

Most cylinder head flow data is reported @ 28" H2O. I checked the original article in the magazine and that's the pressure they used in the tests.

I have not had much success with the forced induction part of Dyno 2000. What you really need is the compressor map for your blower. Vortech publishes some of their maps, but I've never seen one for Procharger.

cobra marty

I got my Desktop Dyno and Performance Trends both up and running and so far the PT wins hands down. The DD is ok but the PT has many more examples and data for heads and cams.

Turbojack

CM- Is this the program you got performance trends

TC- Since I posted yesterday I have read the notes on the program & looked at vortech's web site. They show all of their maps & in looking at maps I now see the information I need to get good numbers. Monday I am going to call procharger ( with my serial #) & ask them to give me the 3 numbers I will need. I do not know why they are afraid to give out the maps but hopefully they will give me this info.

The work on the intercoolers coming along ?

tomcat

Turbojack

Just remember when using the compressor maps that the y-axis is pressure ratio, not boost. And the pressure you use when calculating pressure ratio is the compressor discharge pressure, not the intake manifold pressure.

For example, in the recent Car Craft test of the Vortech BBC kit they said that the boost was 7 psi (intake manifold), but the compressor RPM (engine RPM x pulley ratio x drive ratio) was over 40,000 RPM. When you look at the V-7 YS compressor map on Vortech's website you can see that this RPM line crosses the air flow line (~80 lb/min for 780 HP) at a pressure ratio of ~1.69. That means the compressor discharge pressure was:

(1.69 x 14.7) - 14.7 = ~10 psi

I talked to the engineers at Vortech and they confirmed that the compressor discharge pressure was 9-10 psi for that test. If you don't measure and use the compressor discharge pressure, the map doesn't make sense.

The 3 psi pressure loss is caused by the resistance to air flow in the pathway between the compressor and the intake manifold. Out of this 3 psi, about 1.3 psi is due to the carb, which you can't do much about. The other 1.7 psi is caused by 1 foot of duct, 2 @ 90 elbows and the carb box. There was no intercooler.

If you added an intercooler you would increase the pressure loss from 3 psi to ~4.4 psi. I know this from my flow bench tests and Spearco data on the resistance of their air-water cores. That means with the standard intercooler setup, the compressor would have to develop a discharge pressure of 11.4 psi to get 7 psi in the intake manifold. The higher pressure ratio means more heat so the intercooler would have to be big to deliver that 7 psi air at a reasonable temperature (< 100F).

The intercooler project is going well. I spent most of Friday in the machine shop. The modified carb box is done except for the flange that takes the intercooler. We now know exactly what dimensions we are working with so I will be ordering the intercooler on Monday. I hope to be on the flow bench again by the end of the month. My computer model tells me that I should be able to reduce that 4.4 psi to 2.2 psi, less than the standard non-intercooled pressure loss. We'll see.

I am making sure that each step of the fabrication is documented so that duplication is accurate and relatively easy. I fully intend to offer this as a complete kit with Vortech components, or as an upgrade for people that already have a Procharger carb system.

cobra marty

TJ, That's the program. It comes on two discs and works very easy.

Turbojack

Just got off phone with tech guy at procharger. First words out of his mouth is desktop dyno program is junk. When I asked him to give me a few number off the compressor map I felt he did not have a clue what I was asking. I asked for the cfm flow at the most efficent area of island, he gave me 29000 cfm. I then asked for impellor speed, he said 50,000, I then asked for pressure ratio @ this point & he said he did not know. I guess I will try emailing them & hopefully I will get a good answer.

I have been using one of the choices they have for blowers & been trying different cams & heads to see differences. Looks like my biggest problem is I need some better flowing heads.

cobra marty

TJ, Ithink that I successfully copied the perftrnds programs to CD. I can send the disk to you if you want to try it and see if it works. Marty.