How accurate is Desktop Dyno?

[tonyk72]

I just got a copy of Desktop Dyno & plugged in the numbers for a stock LT-1 and found that the HP & torque numbers are pretty close to what GM advertised. Desktop Dyno gave me 265HP @ 5500 & 246 HP at 6000, a stock '72 LT-1 is 255 HP @ 5600 RPM's.

So I started playing around...I found that if I run headers I can pick up an extra 40 HP at 5500 RPMs!
Then I did some pocket porting & gained an additional 70 HP at 5500RPMs!
Then if I go with larger valves 2.02/1.60 I pick up like 30 more...

With this combo I get 407 HP @ 5500/ 415 HP @ 6000, peak torque is 408 @ 4500. It seems unreal that I could gain an additional 150 HP with these mods.

 

[Thumper]

I've had desktop dyno for about a year now and I do plan on seeing if the real dyno numbers match the desktop numbers. It will be late in the summer before I get to the dyno shop, but this is a questions that I have been wondering about as well.

 

[Utah]

What exactly is desktop dyno? I have never heard of it.


UtAh

 

[BeaterShark]

I have "Desktop Dyno 2000" and ran many (> 5) comparisons against engines built up in Chevy High Performance (CHP) magazine. All of them were within 5% (and about 90% of the time it was within 3%) at any point in the RPM range. The engine combos ranged from mild 350s to solid roller cammed 383s. I entered the head flow numbers for the particular head used, as well as the seat to seat cam timing from the cam card.

Here are my observations:
This is gross HP. The engines in CHP were on engine dyno's with NO accessaries.
Dyno2000 states that seat-to-seat cam timings are better (more accurate?), so you better have a cam card.
If you are using a "street" hyd roller or solid roller, you need to use the "solid" option for the cam. The "roller" option is designated for race roller cams. This is also mentioned in the user's manual.

So, I have come to the conclusion that the Dyno2000 software does accurately (within 5%) give a HP of an engine combo, but it is even more useful for seeing how different components (ie cam, heads, etc) will affect the hp/tq curves.

 

[AKRAY4PLAY]

I have "Desktop Dyno 2000" and ran many (> 5) comparisons against engines built up in Chevy High Performance (CHP) magazine. All of them were within 5% (and about 90% of the time it was within 3%) at any point in the RPM range. The engine combos ranged from mild 350s to solid roller cammed 383s. I entered the head flow numbers for the particular head used, as well as the seat to seat cam timing from the cam card.

Here are my observations:
This is gross HP. The engines in CHP were on engine dyno's with NO accessaries.
Dyno2000 states that seat-to-seat cam timings are better (more accurate?), so you better have a cam card.
If you are using a "street" hyd roller or solid roller, you need to use the "solid" option for the cam. The "roller" option is designated for race roller cams. This is also mentioned in the user's manual.

So, I have come to the conclusion that the Dyno2000 software does accurately (within 5%) give a HP of an engine combo, but it is even more useful for seeing how different components (ie cam, heads, etc) will affect the hp/tq curves.

ya, what he said. my DD2K numbers were off less than 10 for the hp and tq with the 406. i was amazed how close it really was. great tool for figuring combos that will work well for your needs. Brian

 

[tonyk72]

Here it is run on DD stock:

http://users.adelphia.net/~tonyk72/images/stocklt1.jpg

 

[tonyk72]

now add headers...

headers...

 

[tonyk72]

now going all out

ported heads & bigger valves...with free flowing exhaust...