hi guys

i need some input from you guys please.

when changing duration and soi

do you guys only change the SOI or duration aswell. i have heard that guys do 38 deg durations on polo tdi 130pd. and iv'e also heard
not to go to more than 30 btdc is this correct. can someone help me understand please?

For more power you need increase IQ. If this target IQ needs bigger DOI numbers, then you can increase SOI to keep EOI similar as before.

they are many diffrent way of tuning the car...

Its all depending how much power you are looking for. Some tuners increase last 3 columns from 2000rpm, some only tune last column... But mostly good tuner they will touch soi if they know what they are doing, if you increase too much you can get white smoke and always look the temparature from exhaust...

hi,

if you incrise injection duration or IQ you have to increase too SOi...

its all depending for how much you are tuning...

But i can say if you even touch the injection duration map for small ammount i would tune SOI too...
Or you can make your own calculation depending on your IQ and injection duration map you can calculate how much you need to move SOI to keep EOI as standard car has....

Let's assume 2mg of fuel takes 1 degree of crankshaft rotation (°CR) to inject.
Assuming that the injection best time is 0°BTDC.
Start of Injection (SOI) has to be 8 degrees BTDC so that all the fuel has been injected by 0°BTDC

djbalkanac please very much. To explain in as much detail about SOI and Duration. What do they do? What are they? How does it work? How, where and how changes. pretty please.

If you need to ask a question like that, you will need to do some studying on your own...
Plenty of information can be found on public forums and google is your friend...
Duration and soi is very elaborate to explain, please put in the effort and feel free to type down your findings here, then there will be people willing to correct you, if you show the effort...

bogdanwmw wrote:djbalkanac please very much. To explain in as much detail about SOI and Duration. What do they do? What are they? How does it work? How, where and how changes. pretty please.

Sorry guys,
Iepuras, ti-am explicat de 50 de ori,injectia incepe in grade de arbore cu SOI, si dureaza tot grade arbore pe DOI.Vezi in mapa cate mg injecteaza in cate grade(sa zicem 5mg la 2,5 grade rotire arbore), si daca vrei sa bagi suplimentar sa zicem 10mg Diesel, trebuie sa dureze cu 5 grade mai mult, dar atunci trebuie sa decalezi si SOI cu valoarea asta, sa nu-ti injecteze tarziu si sa te caci pe el de motor.
Si mai baga si tu niste engleza ca rad astia de noi :lol: :lol: :lol: :lol: :lol: :lol:

On one tune(tdi 130HP, PD) i saw 43deg of duranation and SOI at 25deg. So end of injection is 18deg ATDC. Egt was so high that turbo last few minutes :(. Very bad tuning.
If you have access to dyno, you can see that injection after 10 deg ATDC doesn't make significant power increase, but egt starts to be very high. What is bad for turbo, bad for consumption and bad for everything.

On a french forum I found a post where one guy claimed he could calculate ideal eoi (or should it have been end of ignition/flame) by the length of the piston stroke and conrod length...