Excellent cogent thread.
As stated by Image, dyno results are misunderstood for the reasons given. It should be noted, as well, that dynometers are also regularly checked and re-adjusted (or should be). So results, even on the same dyno can vary. Lastly, the "pub talk" crowd can't really fathom results. In fact, unless one is using one for a re-mapping, (as Mark Adams, the famous Tornado fellow) rolling roads (the only ones that our crowd should be using, are only vital for Morgans later made before 1990 (the end of the L-Jetronic era). One can only use them for minimal tweaking, like confirming the effect of air filters/intakes, or which gearboxes, differentials, etc or the extraneous stuff that you were not lead too far astray by aftermarketeers.
However, rolling road dynos are the ultimate TUNING devices for earlier generations, those of us running carburettors or L-Jetronic EFI or adjustable aftermarket EFIs. These automobiles have virtually and de facto, fuel maps and ignition timing that are tweakable with a flat head screw driver, a timing light, an exhaust analyzer and a fuel pressure regulator (with EFi). For THIS community, dynos are the very best way to tune a car, not simply for more power (if that is one's thing) but to one's preferred roads, driving style and reliability. I trot to the dyno shop, that has a capable operator I trust, along with the tools I need and whatever I want to try out.
One will often find that there is more fun and reliability at other than simply the maximum bhp one can achieve. Even manufacturers do not shoot for the latter. They want tuning that will cause the least warranty claims within government regs.
gmg
