I’m considering messing with my injector pop off pressures. Iv heard of people having good results with 320 bar with the 75HP sticks. Basically I want the optimal pop pressure for my truck that is not running any tuning just the larger injectors. Part of the reason I’m pulling them is to make sure I have them installed correctly and all washers, o rings, etc are properly installed. Anyways what’s the verdict on pop pressures? 

given your cold climate I would NOT alter pop pressure.  The gains that might be had would be far outweighed by not being able to start the truck.

 

 

the ONLY time someone should alter pop from the normal if if THEY want to R&D with it.   You are breaking you own trail by alter pop.

Edited October 18, 20186 yr by Me78569

With 75's I think 320 maybe to high. Maybe closer the 310.

 

When raising pop pressure you need to adjust the pop for the size of the injector. I think 320 maybe to high for 75's but If you do please let me know how the pop pressure effects your cold starting, stalling and pyrometer temperatures.

Similar sized injectors here from Infinite and he recommended 300 bar.

310 is specified by BOSCH. But I know my 100's were sett to 300 stock, and when I had them popped a few months ago they had dropped down into the 280 range. i would advise somewhere between 300 and 310 maybe 315, but nothing higher.

 

I don't think that cold starting would be your issue, i believe that hot operations maybe your issue..

and I say listen to Infinite lol,

Again dont do it unless you want to mess with it to see the result and blame no one other than yourself when something doesn't work.

IM going back to stock injectors what is good for them?

stock pop.

40 minutes ago, Marcus2000monster said:

IM going back to stock injectors what is good for them?

Why?

1 hour ago, Me78569 said:

and I say listen to Infinite lol,

Again dont do it unless you want to mess with it to see the result and blame no one other than yourself when something doesn't work.

 

That was kinda what I was getting at lol 

 

1 hour ago, Marcus2000monster said:

IM going back to stock injectors what is good for them?

 

Wait so you’re not adjusting your 75hp sticks and going stock??

10 minutes ago, notlimah said:

 

That was kinda what I was getting at lol 

 

 

Wait so you’re not adjusting your 75hp sticks and going stock??

 

1 hour ago, portlandareae28 said:

Why?

That’s the plan. I don’t care for the lag and  smoke. I don’t foresee a Qaud for a while so I would rather go back to stock and see how that goes. 

I've got a set of stock injectors looks beautiful, nice and clean but absolute junk only thing that is good is the bodies. The nozzles and pintles are all shot and the pop pressure is down around 260 bar. If you plan on putting the stock back you better off just having them bench tested and see if they are worth the trouble to put back. Don't get me wrong my stock injectors still run but the spray quality is horrid. 16-17 MPG best even with Quadzilla tuning. 

 

Like my current injectors are closing in on the 100k mark too. I know the pop pressures are off and the quality of the spray is going south on me. MPG are slowly fading on me and its a fight to keep close to even 19 or 20 MPG now. I know I'm due to either replace or re-pop. 

1 hour ago, Mopar1973Man said:

I've got a set of stock injectors looks beautiful, nice and clean but absolute junk only thing that is good is the bodies. The nozzles and pintles are all shot and the pop pressure is down around 260 bar. If you plan on putting the stock back you better off just having them bench tested and see if they are worth the trouble to put back. Don't get me wrong my stock injectors still run but the spray quality is horrid. 16-17 MPG best even with Quadzilla tuning. 

 

Like my current injectors are closing in on the 100k mark too. I know the pop pressures are off and the quality of the spray is going south on me. MPG are slowly fading on me and its a fight to keep close to even 19 or 20 MPG now. I know I'm due to either replace or re-pop. 

IM planning to send them in to get tested.

On 11/26/2018 at 11:07 PM, Marcus2000monster said:

 

That’s the plan. I don’t care for the lag and  smoke. I don’t foresee a Qaud for a while so I would rather go back to stock and see how that goes. 

If that is your issue with the 75's then i would say 310 to 315 bar should get you fairly clean. You could try 320, but I would questions if you don't have enough fueling to offset the pop pressure, especially if you don''t have a programmer.

 

Now granted my 100's only had 33,000 miles on them and they were smokey and laggy and popping off at 280-286 bar, and no amount of programming offset will alienate that. Thats a mechanical issue. My smarty burns dirty, and my 100's set to 320bar I have no lag and no smoke now. And I'm running an S03 with a 550rpm lower stall TC on my truck.

 

It's only about $110 for DAP to pop and adjust them.

5 hours ago, pepsi71ocean said:

If that is your issue with the 75's then i would say 310 to 315 bar should get you fairly clean. You could try 320, but I would questions if you don't have enough fueling to offset the pop pressure, especially if you don''t have a programmer.

 

Now granted my 100's only had 33,000 miles on them and they were smokey and laggy and popping off at 280-286 bar, and no amount of programming offset will alienate that. Thats a mechanical issue. My smarty burns dirty, and my 100's set to 320bar I have no lag and no smoke now. And I'm running an S03 with a 550rpm lower stall TC on my truck.

 

It's only about $110 for DAP to pop and adjust them.

I was quoted 150$ to have them go through my stock injectors. 

1 hour ago, Marcus2000monster said:

I was quoted 150$ to have them go through my stock injectors. 

I just had a set of injectors rebuilt with 150 nozzles. $110 to rebuild/setup, plus cost of nozzles. Talk to Jacob @dieselautopower. I messaged him about it. I also had called in and was told $150. Maybe forum members get a little break.

32 minutes ago, gipperkid said:

I just had a set of injectors rebuilt with 150 nozzles. $110 to rebuild/setup, plus cost of nozzles. Talk to Jacob @dieselautopower. I messaged him about it. I also had called in and was told $150. Maybe forum members get a little break.

 

Maybe Jacob can clarify, but I was quoted $110 because they were already DAP injectors, and getting them repopped and such different?

 

@Marcus2000monster If you decide to pop them, please let me know. I'm writing up an article about raising pop pressure and need more information to try and build a chart for injector size vs pop pressures.

12 minutes ago, pepsi71ocean said:

 

Maybe Jacob can clarify, but I was quoted $110 because they were already DAP injectors, and getting them repopped and such different?

 

@Marcus2000monster If you decide to pop them, please let me know. I'm writing up an article about raising pop pressure and need more information to try and build a chart for injector size vs pop pressures.

You bet. 

I'm next in line I'm trying to save my pennies and spare change for injectors. I've got an awesome set of OEM bodies that are in excellent condition and just got to make the phone call to Jacob and say he they come, get them built. I'm thinking of doing the 320 bar.

4 minutes ago, Mopar1973Man said:

I'm next in line I'm trying to save my pennies and spare change for injectors. I've got an awesome set of OEM bodies that are in excellent condition and just got to make the phone call to Jacob and say he they come, get them built. I'm thinking of doing the 320 bar.

Yup im gonna do 318 i think

Little bit to think about. Why I'm doing what I plan on. 

 

Ok my first set of injectors from DAP was the 7 x 0.0085 SAC injectors had a nasty stalling issue hot. Try re-popping a bit higher and still was having issues stalling made it worse. Then find out it was valve lash causing the stalling issue. Re-adjusted and problem gone by this point I had then redo the injectors for 7 x 0.0085 VCO and set for typical 300 bar. The lifespan is short now the injectors are below usable pop pressure and not quite to 100k miles. I want to aim slightly higher being that even the SAC's when they test dropped an average of -5 Bar from the time built to 2k miles I put on them. I figure 320 bar and the -5 bar settling would land me in the 315 bar realm.

 

 WARNING  - This is all theory and experimental. There is no proof I'm right...