trace a tune on the flow map,am'i ok?

[vadonchez]

Hi guys

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
-Ambiant 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.

My calculations:

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.


EDIT:

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.


Thanks!

 

[vadonchez]

Bump with V7 2+ E40 tune trace on our TD03 flowmap!! We can clearly see how Wedge try to push our turbo in mid rpm while remaining safe above 5000rpm!

 

[Jonas225]

Interesting topic!

I self-tuned my car. Would you share your Excel file with the calculations with me? I'd really like to check where in the compressor map my tune is.
I use a 7.5" stepped intercooler (similar to the VRSF one). Unfortunately I haven't found a pressure drop graph yet.

And about the turbo whine:
I changed my turbos because the wastegate rattle was so loud. I installed OEM MHI turbos. About 1000 km later the whine or rather howl started. They have now been installed for 4 years and they work perfectly. The still whine / how in the low rpm range but they spool really quick.

Here is a log, if somebody is interested:

datazap.me | Jonas225 | R33 Map 4 RON102

datazap.me

 

[vadonchez]

Here is a google sheet link where you can access to the file.
https://docs.google.com/spreadsheets/d/1uhCz5FscP_GhXH5_gQ2gv6uDpX_LfVRnwQW0jssar64/edit?usp=sharing
If there is another easiest way to share my file here please let me know.
I include a JPG of the flowmap, you have to draw your (PR;Flow)points on it manually.

Few IC manufacturer communicate about pressure drop....For me it's illusory to think that IC pressure drop is low like 1 or 1.5psi...
If it was so good, i think that VRSF will communicate on that and claim there products are the best. That's not the case because OEM IC is pretty good on that point and already reach up to 3psi @6000rpm....
You can leave my values as a starting point.


From what I can see on your datazap link, your tune seem's to be close to MHD OTS V7 2+ maps. Our MAF g/s are exaclty the same despite lower WGDC for me, maybe du to the 10°C IAT less on my log or du to my intercooler pressure loss to be less important than yours or du to ambiant pressure of 14,2 for you and 14,6 for me, certainly a mix of thoses differents parameters.
There is a link if you want to compare our logs:
V7 E40 DATAZAP 4th GEAR

Keep in mind that draw your tune on the flowmap works for a datazap link. What I want to say is that, another log with 13psi of ambiant pressure and 45°C of IAT will draw another curve on the flowmap because turbo will have to works more to produce same MAF g/s....

From what i understand and see in my logs, MAF g/s is constant and don't depend from IAT or pressure drop so the X axis don't change.
But PR will change depending on IAT, pressure loss, ambiant pressure etc....

 

[vadonchez]

V10 stage 2 E50 flowmap trace from yesterday's log:

V7 1+ 102RON (E35) from today's log, feel really great and powerfull and seem's to take care of our turbo at high RPM: