Stock 340 dyno tests?
All that is true. However, at a given weight and reasonable car setup, it takes a well understood amount of power to go a certain mph.
And there are plenty of cars out there that run repeatable times. It's quite common actually. So let's not pretend actual track testing is BS.
Let’s not pretend that track testing is the final say in anything.
How easy is it to test say…a set of headers at the track? Near impossible. What about testing two (or more) intake manifolds at the track? Again, near impossible.
What about testing valve lash? Or ICL? Can you do it at the track? Probably. Will it be accurate? Highly doubtful.
What about testing timing loops? See above.
Pretending that the dyno lies is sticking your head in the sand to the reality of what it is and what it does. Anyone can test far more and far more accurately with a dyno than anyone can do at the track.
Spending money on dyno time is the best investment you can make after you build an engine. You can’t possibly accurately test on the track what you can test with the dyno. And you can do it quicker than you can do at the track.
Obviously you have dyno operators who just break in the engine, make a few pulls and send it out the door. The dyno operator is almost as important as the dyno itself. If you have a dyno operator that understands what a typical water brake dyno can do will save you time, money and headaches down the road. Plus, you can find horsepower.
So let’s not pretend that dyno testing is BS. It’s not. It’s far more accurate than any time slip.