Rail Pressure

[Stangshcky12]

I think your pressures are right where they should be
I saw people on other forums saying that the common rail can hold 29k psi fine but I couldnt find actual numbers just here say
Finally came across these
eBay Guides - The Bosch Common Rail Fuel Injection System
The Common Rail Diesel Injection System Explained

According to what I could find 2005 injectors are designed for 1800 bar which is 26k psi

You will hit your rail pressure relieve valve before you damage a injector. I couldnt find an actual number on that but hear say from other forums is 2000-2100 bar so 29k+ psi

I definitely wouldnt stack anything with your tuner now though, they call them pressure box for a reason haha

 

[schroederMP]

I'd hug you right now if you was closer (no ****)

That just gave me a sigh a relief. Thanks for taking the time to find that man!

 

[schroederMP]

And that explains why it will hit 26k and hold...wont go any higher. Once it goes higher then I should prob be worried

 

[Stangshcky12]

I would have never guessed that it was that high, it's an impressive number
You would think that the relief valve pressure would atleast be easy to find
If you do a boosted launch and your rpms fall off rapidly chances are you hit the relief valve
Next time I drive my girlfriends dads truck I'll have to see what it hits on the mini maxx

 

[schroederMP]

Been awhile since I've done a boosted lauch...def have done it since i added my new gauges. I need to get my input shaft install lol

 

[Mopar1973Man]

Correct me if I'm wrong, but doesn't it usually go air before fuel?

So would it be better to do a turbo before nozzles?

Not always...

I've not upgrade either my exhaust or my air... Still running stock HX35W turbo and stock 3" exhaust and producing 400 HP roughly to the ground. No EGT's problems.

AirDog 150 Fuel System
Edge Comp (wire tapped)
RV275 Injectors (+40 HP)

Upgrade what? LOL!

 

[infernoredram]

Well I guess it applies to the ones pushing a butt ton of fuel haha.

At idle my truck is at 7-8Kpsi, cruise at around 15k-18k which I've read is normal.m I can't find anything at wot! So if 26k is normal, would my 21k be just too low?? Would it make sense to turn up my pressure box?

 

[infernoredram]

Took it out for a little drive and noticed on the highest setting on my quad the rail pressure drops a little at 65mph....is it because of my pumps?

 

[Mopar1973Man]

Ok so what's your lift pump pressure like? I know its controversial about fuel pressures for CR engine but the early Dodge FSM stated 9.5 PSI for lift pump pressure was required and then no longer stated. I look at it this way a pump that is properly fed will produce more power under load than a injection pump that is struggling to suck fuel from the fuel tank because the lift pump is no up to the task.

Same problem with all versions of Cummins fuel systems.

VE injection pump with a small 6-8 PSI of lift pump pressure.
P7100 injection pump with 30-40 PSI of pressure but the lift pump is not efficient at high RPM's.
VP44 injection pump with a electric 35 GPH lift pump which was too small for even the stock engine hence the problems.

 

[infernoredram]

I don't know but I need to get that checked out. What you're saying makes perfect sense... I needa upgrade my fuel system already

 

[ladale21]

Well from my understanding, from fluid power, the 26k is not the. Release. Pressure if the injectors are 26k , a 26k injector does not mean its Max output is 26k but when that injector is not firing 26k is all it can hold back, any more and it leaks, I suspect that the 29k is with aftermarket relief and injectors with possibly the pumps , I think stock is 27k relief tho, not sure don't quote me on it tho ill half to go look at the service manual and my Payton number