Ok last week I dynoed my car on the superflow dyno and it measured 403rwhp and 373rwtq. So today I went to another speed shop and they have one of those chassis dynos and only pulled 388hp and 366tq. The numbers for the 1st dyno were STD and the 2nd one was SAE. Which one is more accurate! :shrug:
WTF is up with different dynos!
- Thread starter badctcobra
- Start date
It's easy to get caught up in the numbers and comparing to everyone else. But remember that the purpose of a dyno is to see changes from one modification to the next. Whether your baseline is 380 or 350 the intention is to add a mod, like a CAI and then measure the difference.
I know that's not exactly what your asking, but putting too much emphasis on the numbers between different dynos defeats the purpose. IMO.
:beer:
I know that's not exactly what your asking, but putting too much emphasis on the numbers between different dynos defeats the purpose. IMO.
:beer:
STD is what the car made actually made that day. SAE is a correction factor that corrects for different atmosphereic conditions (outside temps, baromettric pressure, humidity ect) to make the numbers more uniform. When comparing numbers from car to car, modification to modification, ect, the SAE numbers should be used to factor out the different weather conditions.
However, notice my thread called latest MMFF issue. I think our cars may have problems using SAE numbers too, because the correction factors may be based on assumptions that are different for our cars since they are supercharged and intercooled. Many people do not trust SAE corrections, and that is why you often hear that the only way to truely know how much power a modification produced would be to do the before and after mod dyno on the same day on the same dyno. Even then the weather could change, you could dyno in the early morning with cooler temps and then do the mod and get it on the dyno that afternoon when it's much warmer outside.
Dyno's are tuning tools, the HP numbers are overblown to an extent. The true way to tell which car is faster is to line them up and race them. You will see guys here with very similar mods to the exact same mods and tuning, but their hp numbers are 20 hp apart. Like stock dyno numbers that are all over the place. However, my guess is that if you lined those cars up in a race it would be closer than the dyno numbers indicate, assuming equal drivers...
However, notice my thread called latest MMFF issue. I think our cars may have problems using SAE numbers too, because the correction factors may be based on assumptions that are different for our cars since they are supercharged and intercooled. Many people do not trust SAE corrections, and that is why you often hear that the only way to truely know how much power a modification produced would be to do the before and after mod dyno on the same day on the same dyno. Even then the weather could change, you could dyno in the early morning with cooler temps and then do the mod and get it on the dyno that afternoon when it's much warmer outside.
Dyno's are tuning tools, the HP numbers are overblown to an extent. The true way to tell which car is faster is to line them up and race them. You will see guys here with very similar mods to the exact same mods and tuning, but their hp numbers are 20 hp apart. Like stock dyno numbers that are all over the place. However, my guess is that if you lined those cars up in a race it would be closer than the dyno numbers indicate, assuming equal drivers...
STD and SAE are 2 different formulae for correcting results for temp, barometric pressure and humidity. They use different assumptions, and STD typically runs about 4% lower than SAE. Given that, your numbers are remarkably close between the 2 dynos.
The big difference in dynos and results comes between standard inertia chassis dynos (like Dynojet regular models) and those that load the car to simulate road conditions (like standard mode on Mustang dyno). These give different results because car produces different power curve when loaded differently.
The big difference in dynos and results comes between standard inertia chassis dynos (like Dynojet regular models) and those that load the car to simulate road conditions (like standard mode on Mustang dyno). These give different results because car produces different power curve when loaded differently.
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