This image was lost some time after publication.

Dynomometers are by and large useless. Why do we say this when they're obviously valuable for tuning? We say it because they've ruined so many performance-oriented enthusiast mags, turning them into numbers-fests. "Eight Billion Horsepower at Unusable Revs Exclusive! Part XIII!" What if you could simply do your own dyno-fiddling at home? While far from factoring variables beyond intake manifold, rockers, cam, carb and heads, GM's little virtual dyno toy is pretty cool. Check it. [Thanks to Manny for the tip.]

The Ultimate Online Engine Builder! [GM Performance Parts]

Related:
What's the Greatest American V8 of All Time? [Internal]