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      01-27-2013, 05:30 PM   #14
M54ccibo's Avatar

Drives: '16 GT4
Join Date: Apr 2012
Location: Orange County, CA

iTrader: (0)

Originally Posted by Vic55 View Post
Yes you are correct on all points, std correction (SAE is more real world I guess) and grossly underrated our cars are!!!!!

I think I was M5 number four for them so they are building a nice list. Now Im looking for a tune to get us a little more ummmph in the lower rpm range. I love that we peak after 5500 rpm but we dont always live in that range in daily driving especially around town.
I did a bunch of reading last night, and I have more questions than ever about the dyno results. Not just from my car but all dyno results. Short version. I see that there are STD and SAE corrections being applied. From what I have gathered, according to SAE no correction should be applied to turbocharged cars. This is relatively easy to understand as both SAE and STD correct for environmental conditions that manifest themselves in pressure differentials at the intake manifold. On our FI cars, this is controlled as it is under boost. On a NA car, it is important as the intake pressure is the station pressure - which is dependent on dry air and vapor pressure. Change location, day, weather, etc., and these vary causing different results. As such, a need for correction. Oh, and remember, these correct from the actual measured conditions. Are they accurate?

So I think that I have learned is that we cannot accurately compare cars or mods apples-to-apples (i.e., results from various dynos being corrected with SAE or STD, or uncorrected numbers). This does not bother me, but it may for some. Now that I am more educated about what the dyno provides, I am better informed when looking at dyno results. Fortunately, what I did want to see was on my car, did a change cause an increase in HP or TQ and where was this delta observed across the RPM range when compared to my own baseline.

Net result? I think that the only way we can compare any car, exhaust, etc., is to do a dyno day...and hope that that atmospherics do not change from car 1, pull 1; to car n, pull n.

I love that fact that they are underrated. This just makes it that much more sweet when under real-world circumstances we spank a "more powerful" car
Current: '16 GT4
Past ///Ms:
'13 F10 M5, Alpine Weiss III/Sakhir Orange Full
'10 E60 M5, Space Gray/Black