VP Dynamic Timing Vs. Advancing

Is this for a VP??????????????????? if so what year. I know they have 2 different style pickups for the cam positioning sensor.
 
Eric at Left Coast Diesel has said he would be more than willing to get me on the dyno to do some testing. So we will be doing that pretty soon. The big issue right now is, I just cracked the cast elbow coming off of my Secondary charger, and can't hold more than 18psi boost. So I'm waiting on some parts and have to do a little work to the truck, but then we will be good to go.

Also, I need to get back in touch with him and throw out the idea of adding a 2nd truck to the mix. A friend of mine that is still running an SO pump is interested in helping to see if it makes a difference with those pumps as well. This would just give us a better idea of what changes happen with different set ups.

I'll let everyone know when we get things rolling, but I am very excited to see what the differences are.
Sean
 
I hope that ya'll can make something come of this, several years ago there were some pump gears machined so that the center of the gear (holding the VP shaft) could be advanced and retarded at will. As best I remember about 15* worth or so. It never went any further as the VP and ECM were smarter than thought and would negate the mechanical changes electronically. To the best of my knowledge though, no work was ever done on a dyno to get a hard and fast measurement of any changes.
 
Billysgoat said:
I hope that ya'll can make something come of this, several years ago there were some pump gears machined so that the center of the gear (holding the VP shaft) could be advanced and retarded at will. As best I remember about 15* worth or so. It never went any further as the VP and ECM were smarter than thought and would negate the mechanical changes electronically. To the best of my knowledge though, no work was ever done on a dyno to get a hard and fast measurement of any changes.
Click to expand...

There seems to be a difference, but like you said, the dyno will really tell what differences there are.
Sean
 
from Cummins quick serve online
2 3944021 YES ADD Key 1 026
2 3944022 YES ADD Key 1 027
2 3944023 YES ADD Key 1 028
2 3944024 YES ADD Key 1 029
2 3944025 YES ADD Key 1 030
2 3944026 YES ADD Key 1 031
2 3944027 YES ADD Key 1 032
2 3944028 YES ADD Key 1 033
2 3944029 YES ADD Key 1 034
2 3944030 YES ADD Key 1 035
2 3944031 YES ADD Key 1 036
2 3944032 YES ADD Key 1 037
2 3944033 YES ADD Key 1 038
2 3944034 YES ADD Key 1 039
2 3944035 YES ADD Key 1 040
2 3944036 YES ADD Key 1 041
2 3944037 YES ADD Key 1 042
2 3944038 YES ADD Key 1 043
2 3944039 YES ADD Key 1 044
2 3944040 YES ADD Key 1 045
2 3944041 YES ADD Key 1 046

these are all the vp keys listed. the last number is the offset, but i dont remember the difference. I always wondered why they listed different keys fora vp but I guess some of the static timing is different based on cpl etc.
 
Yeah, different VP's are calibrated with different keys, and they are all marked as such. Since different keys have different offsets, that makes me think that the ECM doesn't compensate for different timing, or else there wouldn't be a need for a different offset, they could all run the same key. Or if you switched keys it wouldn't make a difference.
Sean
 
sstockton said:
Yeah, different VP's are calibrated with different keys, and they are all marked as such. Since different keys have different offsets, that makes me think that the ECM doesn't compensate for different timing, or else there wouldn't be a need for a different offset, they could all run the same key. Or if you switched keys it wouldn't make a difference.
Sean
Click to expand...

I wonder if this is going to be an issue where it works only on certain trucks? I remember reading somewhere that if you mix those keys up (like using one from a failed vp in a new one) the truck wouldnt run right at all. Dyno will definitely tell the story, and as more folks try it will tell too.
 
Personally, I believe that the vp44 is going to sense the change and compensate. To make this entire thing happen, we will need to "trick" the vp into thinking no extra timing was added. One thing that you need to consider is "How?" does the vp collect data & calcualte timing? It will still need to gather info showing change so that it can change timing internally iteself as rpm increases. If a box is needed to trick the vp into thinking no timing was added, maybe Chip would be interested in helping? I'm sure there is enough interest to gather his attention.
 
I've read this whole thread and i was wondering if with a comp box [not drag] would unplugging the IAT help me? All i have is an 02 4x4 with sovp with the comp box no other electronics and jammer 3's with a 5-speed .
If so what is the IAT and where is it located?

Thanks,
 
dont unplug sensors. if you gain anything its not going to be much, and who knows what the ECM is going to do when it thinks its -40 out and its really 90* and your romping on it.
 
Rollin Coal said:
dont unplug sensors. if you gain anything its not going to be much, and who knows what the ECM is going to do when it thinks its -40 out and its really 90* and your romping on it.
Click to expand...

~10hp on the dyno is what it will get you. So yea, it's not much.
 
Just read through the whole thread and im really interested. I know I dont have much done to mine, but I gottaa pull the pump to replace lifter cover gasket. Thinkin bout moving it a tooth forward while im there...
 
Red Sleeper said:
Just read through the whole thread and im really interested. I know I dont have much done to mine, but I gottaa pull the pump to replace lifter cover gasket. Thinkin bout moving it a tooth forward while im there...
Click to expand...

Thats the spirit.

I have another truck with a stock SO pump, normal comp, and Jammer injectors that is willing to do the test with me, and I'd like to find an HO truck as well. I need to get back in touch with Eric @ Left Coast Diesel, and see if he is game for having multiple trucks come in and do this test on his dyno. Judging by the interest on this forum, I really hope he is.

I would also like to flush out my testing guide lines a little bit. I want to test 0*, 5*, and 10* on each truck, with the box both on and off. Any other suggestions?
Sean
 
im really curious to see what happens with the SO and HO pumps, then try this on a Monster and a Dragon Flow and see what happens..
 
Red Sleeper said:
Just read through the whole thread and im really interested. I know I dont have much done to mine, but I gottaa pull the pump to replace lifter cover gasket. Thinkin bout moving it a tooth forward while im there...
Click to expand...

I say you will get a truck that runs like crap and has a check engine light on.
 
You must log in or register to reply here.
Back
Top