PD140 and PPD170 MAX SOI ?

kilner

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golf gt tdi sport ppd170
Hello

im just wondering what the max soi is on the pd 140 and ppd 170 engine


stock on the pd170 is around 22 at 4500 rpm


i understand on the pd 1.9 max soi is around 28 and duration of 36 = EOI 8 this is probably the absolout max for the 1.9 with a big turbo


so im wondering what is the absoloute max on the pd140 and ppd170


Thank you for any Information or Direction
 

majesty78

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The 16V engines have a bit different crank/rotating assembly than 8V.

Where useull power to be gained is limited by 6-8 degrees ATDC on 8V you can have about 10-12 degrees on 16V.

At least that is what I have seen in some technical descriptions.
 

kilner

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golf gt tdi sport ppd170
lets just say ther can be a fair amount of power made with even more EOI i had about 44 duration and i incresed this even more and gained 10bhp im not goin to say how much duration but i would not go over 44max as anymore is just goin to add to much heat for how much power is gained


majesty so how much soi is ok ? on the 16v head ? i dont want to blow the head off it :)
 

kilner

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golf gt tdi sport ppd170
a ok np i have an idea so i will try it and hopefully the car will be ok after :)
 

asap03

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lets just say ther can be a fair amount of power made with even more EOI i had about 44 duration and i incresed this even more and gained 10bhp im not goin to say how much duration but i would not go over 44max as anymore is just goin to add to much heat for how much power is gained
So you have SOI somewhere at 36? I don't know if the additional 10bhp worth the risk. You are adding cylinder pressure also...
 

kilner

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golf gt tdi sport ppd170
So you have SOI somewhere at 36? I don't know if the additional 10bhp worth the risk. You are adding cylinder pressure also...
for people that dont understand

soi = start of injection duration is for how many degres the injectors stay open and EOI = End of injection


no not 36 soi lol that would be stupid i think 36 soi would lift the head instantly


22 soi 44 duration = 22 eoi


i have had eoi of 35 and gained 10bhp

but the smoke and egt was no good at all


i think bigger injectors would be a real help as im probably maxed out on soi and duration so the only way to get more fuel in is with biger injectors


any way seems no one wants to say what they are running but i now found out the max soi

:D
 

Rub87

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made around 225hp with stock 16v engine, 2056vk turbo. 24 deg SOI with 38 deg duration at 4k rpm, smokefree offcourse
 

majesty78

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The earlier you start injection, the higher rises the cylinder peak pressure = lifting the head from a certain point on.

With bigger nozzles this effect is multiplied because of the higher injection quantity.

As a negative side effect, you start to create "negative" torque when injection starts to early because the piston is to far away from TDC.

So you loose efficiency if you begin to early.
 

asap03

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Thanks for the answer. So if I put bigger nozzles, I have to retard timing.

Is this happening because if the injection starts too early, the air is not yet hot enough for the auto-ignition because it is not yet compressed enough and the premature injection will actually cool down the compressed charge? So in this case the gas mixture will have more time to saturate, resulting in a bigger boom (that happens still BTDC as you said)?
 
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duke21

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I know this is an old thread, but i have linked question to this...

Kilner said: 22 soi 44 duration = 22 eoi.

How is effective to have such a late eoi? What is difference between 2.0 16v and 8v in effective EOI numbers?
 

Drivbiwire

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There are settings which can net you approx 4 more degrees SOI....

We don't normally apply these since Peak cylinder pressure gets excessive with these if not tuned correctly.
 

poisas

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Thanks for the answer. So if I put bigger nozzles, I have to retard timing.

Is this happening because if the injection starts too early, the air is not yet hot enough for the auto-ignition because it is not yet compressed enough and the premature injection will actually cool down the compressed charge? So in this case the gas mixture will have more time to saturate, resulting in a bigger boom (that happens still BTDC as you said)?
Personal experience, i had stock nozzles, with slightly advanced timing. I have changed in to pp764 so .205->.232 plus injectors pop presure have been adjusted 190->220bar, and timing become retarded, under the bottom line in the vcds.. so i had to advance it.
 

duke21

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Ok obviously when it's so hard to get answer here, i'll share my experience for other. I have SOI 32 on ppd170 and i suppose that is too much. Run for about 40kkm's and coolant started to dissapear with white smoke sometimes. I have changed head once due to cracks. Now when i remove head we'll see if its cracked again or it was due to head gasked/lifting head because too much soi. These are only my assumptions - just trying to learn.
 

DannyS

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Ok obviously when it's so hard to get answer here, i'll share my experience for other. I have SOI 32 on ppd170 and i suppose that is too much. Run for about 40kkm's and coolant started to dissapear with white smoke sometimes. I have changed head once due to cracks. Now when i remove head we'll see if its cracked again or it was due to head gasked/lifting head because too much soi. These are only my assumptions - just trying to learn.
At what RPM do you run this advance? I've read some papers about ignition delay and this delay seems to be around 0.7ms. It depends on injection pressure though; the higher the pressure, the longer the delay. For 1600+ bar it is more towards 0.8ms. The initial formation of mixture takes about 0.3ms (when the cylinder is full of air). Adding these together calculates to about 33degrees SOI at 5000 RPM. Mind that I'm not an expert or tuner.
 

Rub87

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the only real way to get an idea is to measure pressure trace, if you know peak and angle of of peak of the signal then you can have a good idea where you need to be.

at such high load chance is small that one can inject so soon so that the combustion phasing for optimal torque/bsfc is obtained as usually you reach the maximum allow cylinder pressure first. therefore I would just keep reasonable amount to reduce stress on pistons and run lean enough so you stay below 900 deg EGT sustained

at part load timing is usually optimzed so the combustion is most efficient. nowadays with NOx and noise concerns timing is usally later than optimum at emission relavant area.
 

Drivbiwire

Zehntes Jahr der Veteran
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Ok obviously when it's so hard to get answer here, i'll share my experience for other. I have SOI 32 on ppd170 and i suppose that is too much. Run for about 40kkm's and coolant started to dissapear with white smoke sometimes. I have changed head once due to cracks. Now when i remove head we'll see if its cracked again or it was due to head gasked/lifting head because too much soi. These are only my assumptions - just trying to learn.
Your over-advancing more than likely contributed to the cracking of the head.

Your engine suffered cylinder over-pressure and over-temping of the combustion bowl due to the extreme advance you were attempting.

This occurs frequently with stock injectors running a performance tune, a large amount of advances is called for due to slow delivery rates, thus cylinder pressures and temperatures spike... EGT's are low because of the amount of advance being used, all that energy is being absorbed by the compression of the expanding gas volume... Piston skirt scuffing and oil consumption are another side affect.

There is a very fine line on how much advance to allow...

Anytime I see or hear about head cracking, this is traceable directly back to the tune and the maximum allowed advance being employed.
 
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duke21

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Help me Majesty, those are settings i had in two versions of maps. What would you suggest and why? Trying to learn...
 
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