Desk Top Dyno

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I'm going to steer this back to the original question...
I have Desktop Dyno 5 on my computer.
I just finished a W5 build and put all the information (to the best of my ability) in the program.
My build is a 48* R Block, W5 (blue plug) heads done by Ryan Johnson back in 2016 (been sitting on the shelf waiting to be used) I have attached his flow numbers and another set of flow numbers from where I had a local friend double check them on his bench.
2.25 stroke crank with 4.060 bore (440 ci), 13.75 compression, camshaft 276@ 0.050 0.734 lift 110 lobe center.

The Desktop Dyno predicted HP 785 @7000 TQ 673 @5000
The actual Dyno numbers were HP 714 @6500 TQ 642 @5000 on alcohol.
Definitely a big difference... From past experience this dyno is a little conservative, but not that much...

I will let you know what the ET and MPH are when I finally get it all together and to the track, hopefully soon.

W5 Flow Chris.JPG


W5 Flow Ryan.JPG
 

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Last edited:
Greg J. said:
I'm going to steer this back to the original question...
I have Desktop Dyno 5 on my computer.
I just finished a W5 build and put all the information (to the best of my ability) in the program.
My build is a 48* R Block, W5 (blue plug) heads done by Ryan Johnson back in 2016 (been sitting on the shelf waiting to be used) I have attached his flow numbers and another set of flow numbers from where I had a local friend double check them on his bench.
2.25 stroke crank with 4.060 bore (440 ci), 13.75 compression, camshaft 276@ 0.050 0.734 lift 110 lobe center.

The Desktop Dyno predicted HP 785 @7000 TQ 673 @5000
The actual Dyno numbers were HP 714 @6500 TQ 642 @5000 on alcohol.
Definitely a big difference... From past experience this dyno is a little conservative, but not that much...

I will let you know what the ET and MPH are when I finally get it all together and to the track, hopefully soon.

View attachment 1716206354

View attachment 1716206355
Click to expand...
Thank you for chiming in I still think I am going to be able to make my objective with my W5 engine.
Click to expand...
 
I have attached his flow numbers and another set of flow numbers from where I had a local friend double check them on his bench.

The Desktop Dyno predicted HP 785 @7000 TQ 673 @5000
The actual Dyno numbers were HP 714 @6500 TQ 642 @5000 on alcohol.
Click to expand...

The 785hp prediction was using which set of flow numbers?

How do the predicted hp numbers change with the two different sets of flow numbers?

Have you tried manipulating the flow numbers in the program so the power results are closer to actual power numbers?

I will say that 643tq@440ci would be a very good number on the dyno here.
The 1.62hp/ci is also very respectable as well.
 
Last edited:
PRH said:
The 785hp prediction was using which set of flow numbers?

How do the predicted numbers change with the two different sets of numbers?

Have you tried manipulating the flow numbers in the program so the power results closer to actual power numbers?

I will say that 643tq@440ci would be a very good number on the dyno here.
The 1.62hp/ci is also very respectable as well.
Click to expand...
Where do you dyno engines up by you?
 
I’m not at the dyno very often anymore, but I used to do a lot of dyno work for Peter at-

Pizzagalli Racing Engines
Which is now located in Williston Vermont
 
I put the flow numbers in Desktop Dyno that I received from Ryan... And no, I did not try with the flow numbers from Chris...
Now that you brought that to my attention, I am going to take time to do that... Will update on results.

Bill Richardson in Lynchburg VA is who I go to for my work and it's his dyno that is used. He is almost 4 hours from where I live in North Carolina.

I was hoping for more on the dyno, but I'm not dissatisfied, I know these heads are not the best, but I have them, and this will make a very respectable bracket engine.

As my previous, and deceased, machinist Bill Gwynn said years ago when he got a dyno: "dyno's are good for breaking in and tuning engines, but mostly for bragging rights... the track is where the proof is..."

My previous build, put out on Bill Richardson's dyno, 656 hp and 562 tq and took a 2987# car w/driver to a best of 5.96 116mph in the 1/8 mile, and 9.54 @ 141 mph in the 1/4 mile on gasoline.
That's why I think his dyno is somewhat conservative, at least per my calculations...

I will find out about this 440 build when I get to the track...
 
PRH said:
The 785hp prediction was using which set of flow numbers?

How do the predicted hp numbers change with the two different sets of flow numbers?

Have you tried manipulating the flow numbers in the program so the power results are closer to actual power numbers?

I will say that 643tq@440ci would be a very good number on the dyno here.
The 1.62hp/ci is also very respectable as well.
Click to expand...
So, I put in the flow numbers in Desktop Dyno from my friend Chris's flow bench and got the following results:
HP 732 @ 6500
TQ 656 @ 5000
Definitely closer to actual dyno results...
 
PRH said:
From the sounds of it, TVT now has a version of DD to play with.
So, here’s the two sets of flow numbers to compare:

Lift——A/B
.100— 67/74
.200—127/134
.300—183/197
.400—243/252
.500—295/294
.600—350/296

See how the program deals with area under the curve vs the big number @.600 lift.
Click to expand...

Sorry about the delay.

Here is an overlay of the curves with the bigger cam and the above flow numbers. The curve with the dots is the "A" numbers.

1707877492350.png


Here is a chart of the numbers with the "A" port flow values:

1707877683305.png


And a chart of the numbers with the "B" flow values:

1707877644226.png
 
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