Converting airflow from karmans to lb/min

[karbon]

Anyone have a formula? Thanks. Just curious so that I can interpret my logs better.

 

[tim_korn_99]

I was SEARCHING for this answer too, but found this unanswered thread... Would someone please answer this so that when other people are searching, they will find their answer and not have to ask again?
-Tim

 

[Jehu]

It's different for every car and different under different ambient conditions. The Karman Hz basically gives an air velocity reading. The ECU takes this, plugs it into a formula which takes into account the measured x-sectional area, the unmeasured areas in the MAF, the intake temperature and pressure to come up with a lb/min calculation. Short answer, you need more than the Karman Hz reading to calculate lb/min of airflow.

 

[tim_korn_99]

Well, can you get a general idea from the Hz reading? My E316g flows about 2200hz at 20psi on the stock sidemount IC.
Is there like a chart or anything that gives you a general idea based on your turbo?
-Tim

 

[TURFNNSURF]

Hopefully Kyle will jump in on this thread, I read a few other post by him about a similiar topic. Although I never saw a difinitive answer to the Karman to lbs/min conversion.
The reasom IM interested in this, is that during a WOT pull in 3rd gear I have maxed my SAFC II Karman readings at 3000Hz with my PTE GT32E at 17psi. Im just wondering what that translates to in lbs/min thru a 3" GM mas?

 

[CanadianTSi]

Well, can you get a general idea from the Hz reading? My E316g flows about 2200hz at 20psi on the stock sidemount IC.
Is there like a chart or anything that gives you a general idea based on your turbo?
-Tim

You might wanna check for a boost leak because that is quite a high number, I would only see around 2000hz with my Evo 3 16g when I was trapping 111mph is the 1/4.

 

[blcknspo0ln]

jumping on this thread, as I'd like to know too

 

[CanadianTSi]

Honestly there's way to many variables to have a formula that would even be close, I mean if I was reading around 2000hz with my evo 16 and was trapping 111mph and tim korn is reading 2200hz on the stock IC even though i am obviously making more power why is my karman reading lower??? too many variables...