As a matter of fact, Dyno's do lie!
There is a correction factor that can be fudged a bit.
You pretty much have to stick with one dyno as a development tool.
If your engine measures 40hp on your dyno and mine measures 37 on another,
don't go betting the retirement savings on winning a drag race, it doesn't necessarily follow!
Roller dynos and brake dynos often read different, heavy and light rollers will give different results.
All are usually within 10%, and motors will vary that much with weather and conditions.
It is all a pretty fuzzy science. They work best as a development tool.
All that said, Nate still has my attention!
Steve
The modern Dynojet atv dynos have factory set calibration. And the newer ones all read similar. And that consistency has made them the industry standard in the US. There are very consistent too.
The fact is that we have had many motors dynoed on other dynos around the country after we had dynoed them. Sand Trax (Dynojet), Tulsa Oklahoma, GP engineering (Superflow), Garden city Kansas, Advantage Tuning(Superflow) Colorado Springs Colorado, Shearer Custom Custom Pipes (Dynojet), Hesperia California, Adrenaline Powersports(Dynojet), Citrus Heights Califronia. And several in the south, on Dynojets. But I am not familiar with those establishments. In each case the same, or higher power was observed on the other dynoes. So we are quite confident in our dyno numbers.
It is often however, when comparing dyno data on various motors that the common observers misses some of the most imoportant data by looking only at peak power numbers. Or worse, they look at peak toque numbers. Why each bit of information has usefulness, how fast a motors will be in the real world is more complicated than that.
Dynoes don't lie, at least not good ones. But they are often asked the wrong questions.
To determine how "fast" a motor compared to another, one must evaluate and compare the average hp over the usable rpm range.
In a drag race blaster, the best 2500rpm of power will tell the tale.
On a mx style motor 4000rpm could still be relavant to consider.
The most power averaged over the neccessary rpm range will be faster.
And even that is assuming a little much for me. But if the dyno simulates the real-world use, it will give real-world comparisons...