Quote Originally Posted by JeffYoung View Post
It can also be expensive and impossible to prove you've acquired it.

I've got probably 40-50 dyno runs over the last 3 years. 2-3 hp is dyno noise. You get that much variation in results back to back same conditions just minutes apart.
Truth. Checking my hard drive team stang has 67 dyno pulls between the two cars since May 2012. We do statistically analyze our pulls, as well as curve fit them and integrate for area under the curve. We calculate that a couple of percent seems to fall into the noise of the measurement with the noise being comprised of a variety of components.