I'm working on an excel file in order to be able to trace my map on the TD03-10TK3 flow map in order to keep my turbo in safe area.
Picture above show my first results but i need your help to confirm that i'm right.
General undurstanding that needs to be confirmed:
1° On the MHI flow map, volume flow is given in STP (standart temp & pressure conditions wich are sea level (14,7psi) / 20°C), right?
2° On the MHI flow map we can see two indications, 20°C because of STP conditions and 77% on the right. Is it the humidity Hr? If yes, I have to take the volumic air mass with this paramater even if it seem's do not impact results that much.
3° PR is the ratio between turbo output boost and turbo intake pressure, then i have to take into account IC pressure drop and intake pressure loss.
There is my reasoning:
What i need & know trough MHD logs:
- Intake manifold MAF in g/s
- Intake manifold boost pressure
What I need:
- Intercooler pressure drop trough rpm, deduced from the wagner datasheet for my EVO 2 comp
-Intake pressure loss trough rpm (deduced from different reading trough website but not certain i'm right....)
-MAF in Kg/h, deduced from MAF g/s
- Volumic air mass in Kg/m3 known @1,204Kg/m3 for dry air @sea level and 20°C and 1,996Kg/m3 for wet air 77%Hr,sea level and 20°C.
With those parameters i can deduce PR and mass flow in m3/s to report my points on the TD03 flow map.
PR= (ambiant pressure+boost+IC drop)/(ambiant pressure-intake pressure loss)
TOTAL mass air flow (m3/s)= [MAF(kg/h) / volumetric air mass] / 3600
Mass air flow per turbo= Total mass air flow/2
If I'm right, then i can say that my actual tune is pretty safe beeing above 65% efficiency up to 6000rpm.
If we are able to confirm all of my calculations then i can give my source file and help you to graph your tune on the flow map.
For intake pressure loss i found a website where a guy test our oem inlet:
inlet oem test
On the first reading i was surprised because of important drop for so few CFM but i believe that i understood why.
In the link above, I supposed thant CFM are @STP so 14,7psi and 20°C even if that's not write clear.
In our case, CFM pre-turbo inlet is far less than CFM calctualted at intake manifold @STP conditions.
In my case @6000RPM I have around 540CFM with STP conditions.
Because of a PR=2@6000rpm I think that, in reality,i have 540/PR= 270CFM for both turbo @6000rpm and around 20°C of IAT.
Same mass of air into less volume because of PR=2 then half CFM.
So around 135CFM per turbo @6000rpm for Pr=2.
By looking at the graph into the link above we can deduce that oem inlet give around 0,8psi for the rear one and 0,5psi for the front one.
We need to add air fliter drop too so if i'm right (and i'm far not certain) intake pressure drop is an important parameter to take into account when we want to graph a map on a flow map....
I begin to understand the gain from upgrading inlet for aftermarket one.