NefMoto

Hello,
I'm just trying to adapt to two vehicles larger injectors.

A4_1.8T_190PS /new Injektors 630cm³
Krkte = 1EA8E

I can also make a program using Visual Basic,

Meinten Sie: nur habe ich die Rechnung noch nicht ganz verstanden. Kann mir das bitte einer erklären ?
I just have not quite understood the calculation.
Can tell me a please?
Serie 362cm³

630cm³ / 362cm³ = -74 % Krkte is this korrekt  :'( :'( :'( :'(

im using this for calculation
http://nefariousmotorsports.com/forum/index.php?topic=1371.0title=

Thank you,
but I do not understand it properly!
Can adapt to the times of a test in my file?My English is not the best :'(

KRKTE = 50.2624 * Vh / Qstat

Vh: Displacement of a cylinder in dmˆ3
Qstat:  Valve correction for petrol/n-Heptane (g/min)

density of n-heptane is 0.684g/cc

Qstat = 715 cc/min x 0.684 g/cc = 489.06 g/min
1.781 dm^3 engine
4 cylinders

KRKTE = 50.2624*(1.781/4)/489.06 = 0.0456

therefore KRKTE = 0.0456 ms/%


Have here the formula found,what is that "Valve correction for petrol/n-Heptane (g/min)"
Heptone ?Is that pressure?
Thanks in advance

If I remember correctly, Heptane is a fluid with very similar properties to gasoline/petrol and is therefore used as a testbed.

Method 1:

starting from this:
original flow of stock injectors with stock fuel pressure: 317cc/min
original KRKTE: 0,10301

calculate like this:
KRKTE * FLOW = CHEATNUMBER
0,10301 * 317cc = 32,65417

CHEATNUMBER / new FLOW = new KRKTE
32,65417 / 630cc = 0,0518

just change your krkte and the flow of your stock injectors (car should have 3bar)

---------------------------------------------------

Method 2:

new KRKTE = 50,2624 * volume of one cylinder / qstat of injector
qstat is calculated with 630cc * 0,684g/cc = ~431
50,2624 * 0,44525 / 431 = 0,0519

as you see, both times same outcome
remember to check the stock injectors part number to get the right flow
http://www.rexbo.de/audi/a4-8e2-b6-00/1-8-t-13143/einspritzventil-einspritzduese-duesenstock-pde-102799

dont know if this is your car but this 190ps A4 does have 317cc@3bar

and please dont use siemens deka....

Ok Thank you,
new KRKTE = 50,2624 * volume of one cylinder / qstat of injector
where does the value "50,2624 ?
To have the other I think understood ;D

Thanks

50,2624 is fix! You have to accept :P

No, you don't.

You can derive it yourself if you want :)

There are threads here on Nef that talk about it.

Do not accept anything on faith, other than the faith that if you looked into it personally, you'd get the same result.

You can read here http://nefariousmotorsports.com/forum/index.php?topic=935.msg8024#msg8024

But its given Nummer for your calculation. No Need to Change this.
Thats what i meant to say.

Understood :)

Thanks, now it works:-)


lg.

How can I make this formula to E85 Apply?
new KRKTE = 50,2624 * volume of one cylinder / qstat of injector
qstat is calculated with 630cc * 0,684g/cc = ~431
50,2624 * 0,44525 / 431 = 0,0519


Is this worth different 50,2624 ?

Lg

Just add .020 to your pump gas KRKTE.

That's usually dead on.

Do not quite understand what they mean ?

LG

I think he means whatever your current KRKTE is, add 0.020 onto it.

So; if your new KRKTE is: 0.0518, add 0.020 onto it, so it becomes 0.0718.

Yeah? :)

Correct.

Stupid question: wouldn't scaling krkte make more sense than an additive offset?

If you mean adding 20% on KRKTE to work with e85, then this would not be right.
It would be 0.0518x1.20 = 0,06216

.02 is not 20% of .0518 :P

Multiplying by 1.2 on org value is adding 20%.
That is what was the point isn't it?
20% + fuel b/c converting too E85.

Just add .020.

.0518+.020=.0718

I bet it's very close.

Generally, you add around 40% for E85... or so I'm told :)


I bet adding 39% is pretty close too :)

Ok, Where did you get .020 from?
If taking 40% roughly from .0518, then it is correct.

To be clear, I was just being lazy with the .020.

40 percent is a better method to use.

Yes, for Learning purposes. It was a spoon feed answer from your part, but I doubt, OP understood the process :)

Absolutely; sometimes it is really hard to figure out what to spoon feed gently (generalize), and what to be explicit on...

To the OP: sorry to hijack the thread :)

I thought the larger absolute value of KRKTE, the smaller the injector. So wouldn't you actually subtract 20-40% from the KRKTE value?

epy

Nevermind, I just figured out what I said was wrong. You are not actually adding a larger injector, just scaling the ones you have for E85.
epy