About VE, Flow Rates and Turbo Maps

[Tapage]

Thanks for the xls dude ..

This it's specific for your Izusu engine with which turbo . ?

I'm seen about 202 cfm @2000 rpm on 15 PSI of boost .. seem a little more that I already calculate to my engine.

The final conclusion after all this sh***t

It's the K26 it's pretty enought to deliver more boost and flow that my engine can hold ( or I want ) in fact 1.96 PR can deliver 14 PSI and 178.45 cfm that my engine need at 2000 rpm .. figuring 95% - 100% VE and archiving 70% - 72% of the eficience on K26 turbo .. add to this K26 still in the 135,000 max rpm line ..

At less press ratio it can deliver more flow rate with good eficiente ..

 

[Dougal]

Thanks for the xls dude ..

This it's specific for your Izusu engine with which turbo . ?

I'm seen about 202 cfm @2000 rpm on 15 PSI of boost .. seem a little more that I already calculate to my engine.

The final conclusion after all this sh***t

It's the K26 it's pretty enought to deliver more boost and flow that my engine can hold ( or I want ) in fact 1.96 PR can deliver 14 PSI and 178.45 cfm that my engine need at 2000 rpm .. figuring 95% - 100% VE and archiving 70% - 72% of the eficience on K26 turbo .. add to this K26 still in the 135,000 max rpm line ..

At less press ratio it can deliver more flow rate with good eficiente ..

That line you've plotted through the compressor map looks quite good. Now you've just got to check that the turbine side is the right size.
The easiest way to do that is to fit the turbo and see when boost arrives.

The spreadsheet isn't specific to any engine, all it needs is the displacement, turbo compressor efficiency, intercooler efficiency, required boost and inlet air conditions.
The two lines on the graph it produces are air flow with zero boost and airflow with your chosen boost.

 

[Tapage]

My boost start at 1500rpm@ 5-6 PSI ...

At 2000rpm I get 10 PSI aprox .. 2800 rpm I'm getting 14 PSI ..

I thought I gotta weld the wategate actuaton in the turbine .. and see what happend .. any case I'm still out of 1000F

 

[pioneer411]

Firstly pressure.
Your boost guage reads "gauge pressure".
Absolute pressure is guage pressure plus atmospheric.

Then flow.
Your engine can only consume it's own displacement every 2rpm. The VE will reduce this further, but I prefer to calculate at 100% VE and add that factor last.

You need to know the absolute pressure in your intake manifold and the temperature of the air in your intake manifold to work out the volume of that air (ideal gas equations).
With 15psi and no intercooler, expect the air in your intake to be about 1.5 times as dense as with no turbo.
Perfect intercooling can get you to 2 times density, otherwise you're somewhere in the middle.

Then multiply out your engine air consumption by the density ratio your turbo produces (1.6 or whatever you got from above).

That'll give you volume airflow, from there at 20 deg C and a standard atmospheric pressure the air weighs approx 1.2 kg per cubic metre.

I didn't realise you had a 4L engine, I was using 3B figures.

In that case at 2000rpm and 14psi boost with no intercooler you get 12lb/min.

I have a spreadsheet I setup to calculate this. It saves a lot of time.

can send the spreadsheet to me too?? thanks
here my email, pioneer_411[at]hotmail.com

 

[Dougal]

can send the spreadsheet to me too?? thanks

Done.
Now edit your post and delete your email address before all the spam bots find it.

 

[pioneer411]

You can turn up your fuel .. but I'm not sure if the stock pump can compensate 28 PSI .

yes, i think not enuff fuel since i change the turbo.. i get con by someone which i order the turbo not the size i want, but i rushing out for usage, no think much about, and give me fake stuff, plus use already not more then 30minute already finish, end up change comp and turbine wheel. now still ok. running 1.6bar but the turbo too big to me,

now still thinking how to turn more for fuel, since stock pump are not enuff already.
any other way? got other way which is change pump heart, got 6 to change, izzit 9mm? change to 9.5mm will that ok? just replace it

 

[pioneer411]

Done.
Now edit your post and delete your email address before all the spam bots find it.

thanks for the spreadsheet, i try to figure it out kekekeke if more question, hope u dont mind i asking much hahaha
thanks

 

[pioneer411]

Here ya come with some interesting stuff ..

CID = Cilinders Sweept Volume
CID = Cilinders * Bore * Bore * Stroke
CID = 308.36

CFM = (CID * RPM * VE) / 3464
CFM @ 2000 rpm = 178.03 CFM

1 CFM = aprox .0745 lb/min

13.26 lb/min ?

how to count CID? for 12H-T
cilinder * bore * bore * stroke?
cilinder =6
bore =91
stroke=102

but i convert in, the amount crazy much, or it need to divided? or how?
thanks

 

[pioneer411]

That line you've plotted through the compressor map looks quite good. Now you've just got to check that the turbine side is the right size.
The easiest way to do that is to fit the turbo and see when boost arrives.

The spreadsheet isn't specific to any engine, all it needs is the displacement, turbo compressor efficiency, intercooler efficiency, required boost and inlet air conditions.
The two lines on the graph it produces are air flow with zero boost and airflow with your chosen boost.

how to see or count the intercooler efficiency? and how was the inlet air condition? in the spreadgraph writen as what > thanks

 

[Tapage]

I found this chart with very close numbers ..

http://www.buicks.net/shop/reference/carb_cfm.htm

In the CID ecuation .. the CID it's in Cubic centimeters .. must be the same unit that u use in bore and stroke.

Other nice site ..

http://jniolon.clubfte.com/compressionratio.html

 

[Dougal]

how to see or count the intercooler efficiency? and how was the inlet air condition? in the spreadgraph writen as what > thanks

The only way to know intercooler efficiency for sure is to stick temp probes before and after it.
But a value of 0 is no intercooling, a value of 1 is perfect intercooling (cooled down to turbo intake temp). I use a figure of 0.6 most of the time.

Inlet air conditions are standard temperature and pressure. That's 101,300Pa pressure and 20 deg C. The temps are all changed to Kelvin, so they read 273 deg higher.

 

[pioneer411]

The only way to know intercooler efficiency for sure is to stick temp probes before and after it.
But a value of 0 is no intercooling, a value of 1 is perfect intercooling (cooled down to turbo intake temp). I use a figure of 0.6 most of the time.

Inlet air conditions are standard temperature and pressure. That's 101,300Pa pressure and 20 deg C. The temps are all changed to Kelvin, so they read 273 deg higher.

oh thanks, inlet air condition should be no need change it rite? because standard already, roughly.
then the spreadsheet u send me it was 0, its because no intercooler rite? thanks

and after put in all information, how to plot line to the turbo map?

 

[Dougal]

oh thanks, inlet air condition should be no need change it rite? because standard already, roughly.
then the spreadsheet u send me it was 0, its because no intercooler rite? thanks

and after put in all information, how to plot line to the turbo map?

Yes that's right.
As for plotting the information, the spreadsheet gives the flow in all of the different units you'll expect to find. Just print out your turbo map and draw these points on it. Draw a line to connect the dots and you're sorted.

For the vertical axis, PR of 2 = 15psi boost, PR of 3 = 30psi boost.

 

[pioneer411]

Yes that's right.
As for plotting the information, the spreadsheet gives the flow in all of the different units you'll expect to find. Just print out your turbo map and draw these points on it. Draw a line to connect the dots and you're sorted.

For the vertical axis, PR of 2 = 15psi boost, PR of 3 = 30psi boost.

these is some i plotted for my friend isuzu 2.8 4JB1 engine and for my 12H-T engine, try to email back to u, threre got 2 version, and the turbo map, because i not so sure how to plot yet.

 

[pioneer411]

Dougal, i send u a email which included with the map of turbo. thanks

 

[rchalmers3]

My boost start at 1500rpm@ 5-6 PSI ...

At 2000rpm I get 10 PSI aprox .. 2800 rpm I'm getting 14 PSI ..

I thought I gotta weld the wategate actuaton in the turbine .. and see what happend .. any case I'm still out of 1000F

Tapage, Thank you for recommending this thread. Your research about your turbo install is exactly what I am studying.

Preguntas:

Will you please give us an update? What have you tested or changed?
Are you running the same KKK turbo and intercooler?
Did you fix the waste gate and test for max boost? Results?
What is your max temp now? Conditions for max?
What boost numbers are you achieving at 1000, 1500 and 2000 rpm?

Thank you man, it is great to have your participation on this forum.

Rick

 

[Tapage]

Thank you man, it is great to have your participation on this forum.

Rick

Thanks .. apreciate that.

1. Yes I keep the same setup, same kkk turbo and same intercooler, the only thing that I upgrade it's the BOV and more diesel.

2. I can reach a max boost 15 PSI right now .. but this it's running at 100km or more and pedal to the metal.

3. My EGT never go over 1200 not at least I've seen until now .. and that it's sun/hot/rain/night .. conditions, so no matther what I can't get enought diesel yet.

4. 10 PSI aprox @ 2000 rpm but it always depends on my overal speed .. due to my short gearing ..

5. No operative wastegate.

 

[rchalmers3]

It's the K26 it's pretty enought to deliver more boost and flow that my engine can hold ( or I want ) in fact 1.96 PR can deliver 14 PSI and 178.45 cfm that my engine need at 2000 rpm .. figuring 95% - 100% VE and archiving 70% - 72% of the eficience on K26 turbo .. add to this K26 still in the 135,000 max rpm line ...

So here you are saying you calculate your turbo can make 14psi and 178cfm @2000.

1. Yes I keep the same setup, same kkk turbo and same intercooler, the only thing that I upgrade it's the BOV and more diesel.

2. I can reach a max boost 15 PSI right now .. but this it's running at 100km or more and pedal to the metal.

3. My EGT never go over 1200 not at least I've seen until now .. and that it's sun/hot/rain/night .. conditions, so no matther what I can't get enought diesel yet.

4. 10 PSI aprox @ 2000 rpm but it always depends on my overal speed .. due to my short gearing ..

5. No operative wastegate.

And here you say you don't see the caculated boost @2000 due to gearing. Is that correct?

If you were to drive Tencha up a steep hill at 2000 rpm, would you ever see 14psi boost?

Rick

 

[Tapage]

So here you are saying you calculate your turbo can make 14psi and 178cfm @2000.

Yes .. that's the Turbo can do .. but what I've learned in this process and take in mind it's only based in my experience and few web readings ..

Build boost in a turbo engine, it's directly related with the amount of diesel that you can push in the engine and the efford that this engine are doing at specific time.

It means ( and I'm 100% psitive on it ) if would be posible to me deliver much more fuel at lower rpm, I where able to make more boost sooner in my powerband ..

Like iin the 1HD-T

If you were to drive Tencha up a steep hill at 2000 rpm, would you ever see 14psi boost?

Rick

sure yes .. if I'm over 100 km/h pedal to metal ..

 

[rchalmers3]

Yes .. that's the Turbo can do .. but what I've learned in this process and take in mind it's only based in my experience and few web readings ..

It means ( and I'm 100% psitive on it ) if would be posible to me deliver much more fuel at lower rpm, I where able to make more boost sooner in my powerband ...

I never thought the IP adjustment could be a limit for a small boost of 1 bar over atmosphere. In your opinion, is this situation special to Tencha?

Could there be losses of efficiency in your intake installation (or assumptions in VE) that you have not accounted for that affect the building of boost?

Believe me I am interested in solving this puzzle. Si la bomba injeccion esta el limitaccion por el produccion boost, es muy importanta a mi.


Rick