Turbo Magazine dynoed a 350z at multiple places to see what kind of numbers they were going to get. Here's the link to the article.
http://www.turbomagazine.com/tech/0306tur_dynodash/
Check it out. #'s vary quite a bit.

 

Hmm, informative thread. It's good to see that although the dynos vary between each brand (type), each one is fairly consistent with itself. I guess this goes to explain some of the dyno differences people have seen.

I wonder if people should start posting hp gains as percentages. I assume that a mod that showed a 7 hp gain measured on one of the higher scoring dynos would only show a 6 hp gain on one of the lower ones.

 

Conclusion

The genesis of this article was to satisfy a curiosity itch we, and many other industry insiders, have. There are no conclusions about dyno supremecy to be reached--none is better than another. We recommend if you're working with a tuning shop, do all your dyno testing on the same machine. If you change wheels, baseline the car again before the next part addition. If you change shops, baseline the car before the next part addition. Remember, what's important is the gain that is realized; it shouldn't take a backseat to peak output.


I been telling this for a long time now!!!

 

Yup, I just wanted to show everyone that dynos are best for mod. gains only. Also, like the article says just stick to one dyno place if possible.

 

It would have been complete if they had just added an engine dyno to, and compared the shapes of the curves to each other. At least we'd get an idea of which on was giving a better overal picture to the true power curve. The Dynapak TQ curves looks crazy, and Ive seen much worse. Also, the DynoJet, which most ppl use, had the greatest variance from run to run, about 6.5 HP. This means you need to make many before and after runs to get a sense of the gain from things like grounding kits, intake, and exhausts. All these posts showing 2-10HP gains are pretty much meaningless when you can gain almost 7 by just doing another run.

Mark