Engine/Transmission (1998.5 - 2002) VP44 Timing

[csevers]

Can/will any body tell me how much timing you can get from a vp44 how much retard and advance. I have not seen this info anywhere and am interested in how much the box makers put in as far as timing and how much the pump can really make all out regardless for the bad effects of timing on the engine or pump.



Thanks

Craig

 

[Hohn]

There's no theoretical limit to the timing you can get from the pump. All you'd have to do is manipulate the signal from the Cam/crank position sensor.



But I think you're asking about the RANGE of timing the pump can do based on ECM manipulation. I'm sure that the ECM is what limits the advance/retard the VP will apply.



As for the capabilities of the pump, you're probably referring to the range of motion of the cam ring. I can't help you there. If you had a pump in pieces, you could measure the movement limits of what the solenoid can apply to the cam ring.



I'm guessing that from one extreme to the other, it's probably less than 9 or 10 degrees.



Justin

 

[A Johnson]

I believe it is from 0 to 30* BTDC. I am going by memory.



A Johnson

 

[csevers]

I am sure that the pump has mechanical limitations ie the cam ring movement. The real heart of the questions is can you get enough timing to make it worth the work of making a cheat to bend the eletronic signals. If I could get 30 btdc I would be a very happy man!!!



Next question is does the timing change with load or is it contstant with increase of rpm. Anybody ever check with a timing light??



Thanks

Craig

 

[A Johnson]

Never checked with a timing light. Most all engines that have the capability will change timing based on load, coolant temp, intake temp, boost pressure, commanded throttle , and engine speed. Most Cummins engines retard timing as load and temperatures rise to control cylinder temperatures,pressures and emmisions. I would assume the ISB with VP-44 does the same.



Don't the electronic add on boxes basically manipulate the signal to achieve what you are asking for?



A Johnson

 

[Hohn]

One of the main reasons they switched to the VP from the P-Pump was the VP's ability to change timing. The P-pump is dumb and only has one timing for all conditions.



30° is a large range of timing. This kind of flexibility is great. You'd think the VP44 trucks would get WAY better mileage than the P7100 trucks then.



The ability to advance timing to "extreme" levels under very light loading is one key to good mpg. Think of the vacuum advance on gasser distributors.



It sure would be nice to see the timing maps in the ECM for different load, temp, and APS positions. It would be nice to see how a box like the EZ affects this as well.



Justin

 

[Bob4x4]

I have seen as high as 50 degrees recorded on freeze frame info screen. I have not seen or heard of any paper documentation of advance numbers.



Bob

 

[GregFisher]

Injection Pump Advance Is 15 Degrees On The Test Stand Which Would Equate To 30 Degrtees On Engine

 

[csevers]

The "Timing" boxes due add timing but not Extreme timing needed for competition. My Redline box from BlueChip is doing its job but I feel I am not geting all the hp that I could at 4k with out some more timing. If you take a 12v in to the upper levels of timing you can HEAR it!! And this is kinda what I am looking for, to flip a switch/turn a dial and put more timing in as "I" see fit. As far as if the ecm changes timing with load,temp,rpm and such is only usefulll in figuring out how to "bypass" it. I don't think this could be to hard for the right Computer savy person to do if they can over ride the fueling now it should be just as simple to fool the computer for more timing.



Thanks

Craig

 

[HoleshotHolset]

If we're talking about a race-application... . hrmmm... .



I don't have my handy dandy 'spare' VP44 shaft here in front of me (its at work on my desk... )... but there is a reluctor ring on it that actuates the angular encoder.



The angular encoder picks up the position of the shaft and sends it to the little brain under your pump cover... from there the ECM figures out how to control the solenoid valve to divert the fuel in the distribution section... and make injection events.



Moving the angular encoder inside the pump isn't going to make any difference... BUT, what if you could weld up the old grooves and machine new grooves into the OEM reluctor ring?



Since the shaft is sorta indexed to the radial plungers... you could advance the timing by messing with the reluctor ring, right? The ECM wouldn't be wise to the change as it relies on what the encoder tells it... The other fancy part would be to make sure that you have enough 'fill time' with the radial plungers... the eccentric inside the pump would have to be moved the same amount as the reluctor ring so that your high pressure is being created at the right time.



This wouldn't be easy by any stretch of the imagination (and it may not play out in real life like it is in my head... )... but was a thought I had...



Here's a picture of the eccentric... ain't it purty?



Matt

 

[rmackay1]

eurreeka Matt, that's a hell of an explanation, well done, is that a picture of the inside of a VP44?, if it is you are the man! I'll buy a pump off of you, ray

 

[GregFisher]

Matt, With The Software That Bobby Bosch Provides Us This Would Not Be Possible, However If You Know Someone At Microsoft???

 

[AKAMAC]

Matt, I can see you slowly drifting over to the X2 side! If you can, drive a truck with a modified ECM.

Mike

 

[HoleshotHolset]

Ray: Yes, that is a picture of the inside of a VP44. I have one (with a seized distributor section) that is all taken apart so that I can tinker/learn.



Greg: Bosch's software expects the reluctor ring to be at a certain place at a certain time. The modification I suggested would not affect the timing as far as the pump/ECM would be concerned. The whole shebang would basically be under the impression that everything was just fine since the reluctor ring would still have the same 'pits' at the same intervals...



Could it be as easy as installing the pump 'off a tooth' (advanced)? You'd probably have to mess with the crank/cam trigger... This is getting complicated.



I'd love to drive a truck with a modified ECM... but, I don't believe that a modified ECM will allow the type of timing advance that Craig is talking about.



He could just convert to a P-7100 and call it a day, though.



Matt

 

[HoleshotHolset]

It has been 3 days since I checked this thread and not even one person has commented on my (possibly retarded... pun intended) ideas.



I expect more out of you guys! :-laf



Matt

 

[A Johnson]

O. K I'll Bite.

I know if you unplug the crank sensor before you key on and start the engine, the ECM isn't smart enough to know when the fuel pump cannot reach commanded timimg,we tried this in the ISB training I took at work and it did not throw a code 368 when we introduced air into the system. The air previously caused the fuel pump to not reach commanded timing and the ECM knew it, until we unplugged the crank sensor before starting. Maybe your on to something. Not sure how this works on engines that have eliminated the crank sensor, maybe you have to unplug the cam sensor.

Could you unplug the crank sensor and put a severely retarded or advanced key in the fuel pump and make it fly? I do not know, just thought I'd throw it out there as were just talking anyway.

A Johnson

 

[HoleshotHolset]

I'm not talking about eliminating the crank or cam sensor... but you'd have to mess with whatever reluctor ring the sensor is... umm... sensing.



The ISB's with the reluctor ring on the crank would not be fun to mess with... right Aron?



If you mess with the pump... you gotta mess with everything else that knows about the 'timing'... starts a chain reaction so to speak. Just like replacing steam pipe... before you know it, you're back at the boiler.



Matt

 

[csevers]

In my research so far it apears that it is going to have to be a electronic "hack" or internal pump mod to get it done. Mechanical changes lead to a dead end.



Craig

 

[HoleshotHolset]

Well... the electronic hack is only going to be able to go as far as the solenoid valve's mechanical limits. With some boxes allegedly adding a second injection event... this solenoid is already taxed beyond belief.



My vote is for internal pump mods... that's the only way to get a LOT of timing.



The other alternative is to install a P-7100...



Don't let other people's 'bad luck' with that swap get you down. I'm convinced that it can be done and have excellent results. Awww heck... just bolt on a hogged out 12-valve head with huge valves and call it a day - you've always wanted fire rings anyhow... !



Matt

 

[zstroken]

Bosch software

WHat is this bosch software? does it allow us to get over the governor speed on the VP44??