pop pressures dssr .360

Hello.

Now I got some big nozzles the DSS r .360
On a stock 220-300 bar injector. They decrease the pressure to 200 bar first stage.
When swapping them without adjusting. When testing the. The nozzles don't heard that cracking sound when they pops.
So that's why I think pressure is to low.

So at what pressures work these it best ?
Good spray pattern and Max flow.

I have heard around 240 - 320 bar .

How thick shims do I need to up the pressure by 40 bar ?

First stage 280bar.

Yucca thats high then second stage is 360bar?

Me thinking more around 240-250 and 320-330
this is because of pump stess. and so you got more flow then setting them so hi

Yucca thats high then second stage is 360bar?
Me thinking more around 240-250 and 320-330
this is because of pump stess. and so you got more flow then setting them so hi

How many injection pump you have broken with too high opening pressure?


I use 260bar if nozzles are between R520 - 0.280. 280bar with 0.341 and larger.

Yucca have you tried a single stage injector ? I'm not sure if there is much real world benefit in terms of performance.I have converted mine to single stage at 250 bar If I recall correctly.

The 2 spring/stage system was made to reduce combustion noise I thought ? Its possibly not ideal for all out power or even fuel economy as it takes away from peak cylinder pressure.

I have worked with modded engines having single or 2 stage systems like such as the 7.3 powerstroke for example.The newer 2 stage truck guys would sometimes swap to the older single stage injector and have the pcm re programed to run the single stage injector as it's injector was pcm controlled.

Anyone with thoughts on this please feel free to chime in.

andy2 said:

I have worked with modded engines having single or 2 stage systems like such as the 7.3 powerstroke for example.The newer 2 stage truck guys would sometimes swap to the older single stage injector and have the pcm re programed to run the single stage injector as it's injector was pcm controlled.

Anyone with thoughts on this please feel free to chime in.

Click to expand...

The two stage injectors used more high pressure oil, and you could get away with a larger aftermarket single stage in their place before running out of HPOP. IIRC that's why the super duty HPOP was bigger than the pre-'99 ones and is considered an upgrade for the older engines.
Completely different reasoning and system than our engines use.

On our injectors you can increase the pintle lift pretty easily while converting them to single stage operation. Just remove some material while taking the "shelf" off of the top-hat shaped piece.
Trying to increase pintle lift while keeping the two stage injection means some much more involved grinding work (either grinding on the top side of the 'hat brim' of the "top hat shaped piece", or deepening the pocket in the spacer it fits into) or alternatively shortening the pintle itself, but that will increase the duration of the pilot injection stage.

All of it has to be done to reasonably close tolerance, mine are a couple tenths off of each other, closer than the factory ones were to each other, but they may very well be selective fit parts, used to vary the pintle lift at the factory to match the flow of the injectors.

got today mine dssr.360 nozzles in the car, pop i set them at 240 bar.

they give a little more fuel than old hflox .275
I thought that the give a lot more fuel buth that's not the case.
maybe 10% max.

they smoke very little, the hflox.275 I was almost 100% smoke free, now I got very little smoke

I just swap them over same pump voltage as old nozzles, now fine tune it and hit dyno hope to do a bit over 300 hp now.

By reading, it seems that you are only chasing numbers.

BTW, smoke level shouldn't be the gauge for injected quantity because atomization (nozzle design and also opening pressures settings) as well as SOI have both huge impacts on smoke level

Yes you're right I got higher pop pressures 240 dss-r. 360 and 220 for hflox .275.
Higher pop pressures better atomism of fuel so less smoke.
Isn't that you can limit the flow of a nozzle to set the pop pressures higher ?

Visually I see big difference in hole size. I thought they give a lot more fuel.
The car feels almost the same maybe 10 HP more. Maybe I'm wrong time to hit dyno.
If they don't work maybe try hflox .341 ?
Ore the 12.5mm pump head.

I have seen 330bhp with dssr 0.360 and 11mm pump. Dont blame nozzles if you have lower numbers.

Hi Yucca

Nice number for a 11mm and .360
What turbo and boost it is running.

When tune is ready I m hit dyno looking for 1:16 AFR and 300+ HP
The engine smokes very little now and little power bump.
I m sure that the turbo is at Max and fueling to.
Back then with gtb2260 and .275 maxed out I got 277 HP with alot smoke .
Then after swap turbo almost no smoke very little haze grey.
Now it's little more and almost black.
I'm sure I got a bit of hp true turbo and nozzles maybe +25 ore maybe +40
I can't say.

I think it was S200V hybrid, 2.5bar or so.

mk1-83, Are you sure your lift pump delivers enough fuel to the IP?

Hi Markus I don't check it got 2 pd liftpumps around 0.7 bar at idle drops to 0.5 flat out in 4. Back time. I can check it for sure. I can hear the pumps working when I start and idle.