View Single Post
      10-01-2019, 02:58 PM   #18
First Lieutenant

Drives: 2015 335i, 2015 X3 x35i
Join Date: Aug 2018
Location: Chelsea, MI

iTrader: (0)

Originally Posted by johnung View Post
I was able to pull the MAF values at a range of RPMs from your before and after logs and enter them into the attached table.

It's interesting that your airflow numbers from 3000-3500 RPMs are significantly lower with the Pure Turbo inlet pipe.

There was no difference from 4000-4500 RPMs. But there was a significant 8%-9% airflow increase from 5000-5500 RPMs and an airflow increase of 4%-5% continued from 6000-6500 RPMs.

Of course this is all assuming that the logs were taken under exactly the same conditions and there were no other variables. Also assumes that this is reproducible if more before and after logs were taken.

I'm not sure how to account for lower air flow at lower RPMs. I don't remember much flow dynamics from physics class. The main physical difference between the two pipes is that the PT pipe does not have the constriction at the end so it can handle 42% more flow than the stock pipe right as it enters the turbo.

This is pure speculation on my part but maybe the larger PT pipe exit reduces velocity at lower RPMs so that actually makes for less flow until engine speed increases enough to utilize the higher flow capacity of the PT inlet pipe.

Pray For Mojo did you notice less engine response below 4000 RPM? Are there any flow dynamics guys out there or anyone else who has added a Pure Turbos Inlet pipe to an N55 with a stock turbo? Please chime in.
Velocity... exactly
2015 335i xDrive
2015 X3 x35i

IG: @N55David