I brought my car to a dyno once, it was a "load" dyno...Every change I made to the car on the dyno that had it pick up there, slowed it down like crazy at the track. Needless to say, I am not a big fan of dynos, unless of course the load dyno had something to do with it
Great way to sell dyno time, change correction factors, show the customer a positive gain no matter what the car really did..
The ironic thing about this thread and hundreds of others like it is this simple FACT. I dyno can't lie. It is IMPOSSIBLE for a dyno to lie. Neither can a flow bench lie.
The simple FACT is that dyno operators lie. Flowbench operators lie. It's that simple. And a liar is a liar.
There should be less than 1% difference bewteen any dyno's out there, IF they use the SAE correction factors. If they don't use SAE correction factors, it is because they LIE. Same with a flow bench.
So to hear all this [censored] about a dyno is just a "tool" and the numbers don't matter is compete [censored]. We know EXACTLY what horsper and torque are. They can be defined verbally and mathematically. So they are KNOWN VALUES. And we KNOW, for a FACT, that a KNOWN hp, and a KNOWN vehicle weight will produce a KNOWN, minimum ET and maximum MPH. So, if you dyno your [censored], and go to the track and it don't run what HP the dyno said you have, either the dyno operator lied (seen this a million times), the car is heavier than you think it is (seen this a million times as most bracket racers don't actually put their stuff on scales and their ass guesstimates are never close), the chassis is not tuned/junk, or the timing equipment is junk.
A similar analogy can be made with a tach. Is it just a number, a "tool", or can we verbally and mathematically define RPM? Certainly we can. If your tach was off by 10 RPM, would that be an issue? Not really, What about a hundred off. Could be slightly problematic, but still not bad, as most guys are not 100 RPM accuratre in anything they do. What about 1000 RPM off?, Now we have an issue. It is no longer a "number" because the difference between a 7800 RPM shift and a 8800 RPM shift is a big deal. So it is with measuring instruments of all types. 5 good, competent machinists, all using their own mic's, set to a standard, should all be able to read the demisions of a part to less than .0003 at the maximum. They are not C clamps. Set to a standard they should measure the same. It's the same thing with a dial indicator (because 1.6250 inches is EXACTLY 1.6250 inches), or a flow bench or a dyno.
What if the measurement system for a drag strip was not the same lane to lane? It's the same thing.
Tools don't lie.
Jackasses that use the tools lie.
