The lads meet at Turbo Tune in Greensboro, NC. The shop has a chassis dynometer there, he straps your car down on the rollers and you floor it. From that you get a plot of horsepower vs. rpm, and a plot of air/fuel ratio vs. rpm. Last meet cost about $60 for 3 runs.
It's interesting. From that, I found out my Probe is down about 30 horsepower from where it should be. And burning rich at the high RPMS. Worth doing. But I don't want to go back until I'm certain I've found the missing hp, and so far I don't think I have.