Nicks Garage 383 build

92b said
I agree test proceedure and control over variables are very important.
I think correction factors are most useful when comparing data on the same dyno on different days. I also think correction factors are more accurate when they don't have to correct very much. Unless you are testing under conditions close to 60 degrees, 29.92 pressure and 0% moisture, why wouldn't you use a correction factor closer to the actual conditions you are testing at? I can think of a few reasons and these are not without some merit.
1. Everybody else (my competitors) uses it.
2. That's how I have always done it.
3. I can't or don't know how to change it.
4. I didn't know there was an alternative.
5. It gives me or my customer bigger numbers.

Just to name a few I'm sure there are other reasons.
Just so you don't think I am "correction factor Shaming". I have three correction factors loaded into my dyno program. I do all my testing with the CF that is closest to my conditions J1985. If it is a street or non competition type motor I will also offer (with a shortish explanation) the "higher" numbers with the J607 standard. I ask the customer which they would like me to print out for them. Guess which one they choose? If I were them I would probably pick the bigger numbers. It's human nature I think.

I guess my answer is what difference does it make? The observed numbers is what the engine sees.

You could correct to a 30.5 barometer, 45 degrees and 100% humidity and what would it matter??

You almost never get conditions to match any correction.

So I use the STP correction and you use one of the other correction factor and Ramm uses a different one and PHR uses a different one yet.

And we all test the same engine and ship it around so we can all test. We all test at different correction factors so we all have different corrected numbers and observed numbers unless two of us got lucky enough that we were testing with conditions so close the observed numbers were close.

And what did we learn by doing that test? Nothing. The observed numbers are only good for those weather conditions. The corrected numbers are the same. The engine will only make corrected power when the conditions are met.

Trying to get corrected numbers that standardize everyone doesn’t matter. I think the STP correction is no better or worse than any other correction factor.