I'm wondering if this tool is even remotely reliable for judging mods. Has anyone compared a Gtech Pro result to an actual dyon run?

 

HP numbers will never be the same on the GTtech vs a dyno.
Reason is that the GTPro will give you real world numbers.

Howerver you can compare the GTtech vs the Dyno SAE version. These would be similar in results.

I'll give you an example.
- A dyno run on a stock mustang would tell you around 270HP
- the GTech will tell you abount 230HP.

And Both results are correct.

Basically you add 30% to the GTech value to get a HP rating for you car.
Similar to adding 15% to dyno value to get the HP rating.

 

Actually to take my question a step further, I guess what I really mean is:

Is the GTech Pro a reliable tool to judge mods in that if I add a CAI and I see a 20HP increase on the GTech would I also see (at least) a 20HP increase on the dyno?

Also would you say that a Mustang Dyno falls somewhere between the GTech and a DynoJet as far as expected HP numbers?

 

It is reliable. You just have to add 30% to all your numbers for your actual HP rating.

Or add 15% to all your numbers if you want the equivalent of Dyno numbers.

But yea...any mods you make you will see differences with the GTtech, just like a dyno.

 

Cool...thanks!

 

I think it's a good tool / instrument to judge the relative impact of changes. Results will depend on the consistency of the test conditions (total weight, tire pressures, wind, temperature, etc.) and the driving. Also the test straightaway needs to be the same section and direction of road for the test. A few horsepower may not be that detectable.