Durration and SOI - how far can I go?

by **Skipper** » Tue May 10, 2016 3:47 pm

Hi

I have the basics down, but I need info on how far I can go on duration, and if I should at all touch SOI

Im thinking about 40 deg duration/4500RPM, but would like to go further. Do not know if I dare touching SOI, and if so, by how much.

VAG 1.2tdi 61hp. EDC15p+

Ori file attached

Any help is appreciated :-)

by **Ionut** » Tue May 10, 2016 6:28 pm

You have PD engine, so you are limited by camshaft shape. Why would you like to go over 40 deg?
SOI MUST be changed for better performance/mileage improvement.
Don`t go too much because if you go far away the fuel pressure on the end of injection will be lower, atomization of fuel will be poor and EGT will rise up quickly, so most probably you`ll end up with blown engine.

by **Skipper** » Tue May 10, 2016 10:11 pm

Well I would like to go over 40 deg. because I would like to inject more fuel than I can manage on 40 deg.

Yes I would like to change SOI, but please help me out here. How much can I advance it? 2-3 deg?

If you were to do a MAX power tune on this engine, what would you do?

Thanks

by **Ionut** » Wed May 11, 2016 7:22 am

Skipper wrote:..
If you were to do a MAX power tune on this engine, what would you do?
...

I would change engine with a 1.9TDI.
Is not important TO INJECT a big quantity of fuel, is very important to inject all that fuel QUICK ENOUGH. If you inject too early you`ll loose power, if you inject to late (ex: more than 40 degrees of duration) you`ll loose power and EGT will be huge.
To inject more you need to upgrade your injectors nozzles. FIRAD is a good start

by **Skipper** » Wed May 11, 2016 10:51 am

So basically, dont pass 40 deg, and dont touch SOI. Is that correct, if I do not want to change injectors? Are those the upper limits?

by **Ionut** » Wed May 11, 2016 1:45 pm

SOI can be raised. Add 2 degrees and test car. Then increase just last 2-3 columns depending on how you edited those columns to allow control for higher injection quantity.

by **Skipper** » Wed May 11, 2016 10:17 pm

Thanks :-)

OK, so if I want some real power from it, I need bigger injectors I see.

Can I swap to injector units from another tdi pd with higher flow injectors? or do I have to fit new nozzles? (would be a lot easier just to switch units :-)

by **Ionut** » Wed May 11, 2016 11:43 pm

If you find other injectors bigger enough is your choice, but after this you`ll need to rescale your duration map to fit new flow

by **waynemodz** » Fri May 13, 2016 12:56 am

SVBL is 2300mbar,
If you refer to the PD130 that uses 2300mBar you will see it only needs 47mg for that boost,
If I had to extrapolate I would stop at 33 degrees, OEM SOI looks high enough for 33 degrees,

Also note,
25mg - 1810mbar
30mg - 2013mBar

We can assum 35mg can use 2216mbar but if you extra polate from 35 then 40mg can be 2216, depends on the afr you want to go,
i personally think 45mg and 2200 mbar @ 4000 rpm should be your limits.

So rescale the map for 50mg. :thumbup: