VP Dynamic Timing Vs. Advancing

[cummins724]

Originally Posted by 01CumminsSport

ya i used a keyway that should be good for about 5* timing for the pump and i have 6* for the cam,

the s472 as a single is fun and all but it likes to heat soak before it gets lit and starts to cool things off so i go through alot of water with the truck, but it does surprise people how you can drive around the back roads with no boost and it runs fine then you let it lite and it will burry you til you run out of gear

Wonder if advancing cam timing will actually help? I was gonna try advancing the pump only. I'm gonna try to locate a timing light before doing it, this way we see what is happening.

[sstockton]

Originally Posted by cummins724

Wonder if advancing cam timing will actually help? I was gonna try advancing the pump only. I'm gonna try to locate a timing light before doing it, this way we see what is happening.

I'm with you on that one. I really want to try it with a timing light and see what it shows. I'm also really curious to try advancing the cam as well. I need to pick up some of these 6* keyways.
Sean

[cummins724]

I'm gonna be a while before I get to mine. I am spraying bedliner on my rockers tomorrow, then I gotta do a Airdog install, a headgasket on my brothers 98.5, then paint 2 cars before I get to do my stuff.

[01CumminsSport]

Originally Posted by cummins724

Wonder if advancing cam timing will actually help? I was gonna try advancing the pump only. I'm gonna try to locate a timing light before doing it, this way we see what is happening.

i have the cam at 6* advanced right now and the pump at 5*, i did loose 5 lbs of boost while staging from advancing the pump timing, but if i shut the comp off it will come back up to what i was at

[cummins724]

Originally Posted by 01CumminsSport

i have the cam at 6* advanced right now and the pump at 5*, i did loose 5 lbs of boost while staging from advancing the pump timing, but if i shut the comp off it will come back up to what i was at

I called a friend today, not looking good for the timing light. I'm still gonna try it & see if I gain revs.

[weazel]

Originally Posted by 01CumminsSport

i have the cam at 6* advanced right now and the pump at 5*, i did loose 5 lbs of boost while staging from advancing the pump timing, but if i shut the comp off it will come back up to what i was at

so taking out the added electronic timing added more boost?

[01CumminsSport]

ya when i turn the edge off or down the boost would go up some

[bosshogg]

well then that must mean that 5* plus electronic advance over-times the injection event-at least when building boost. What happened up top?

[01CumminsSport]

with the electronics off i will do just over 40psi and with the edge back on and i using it for just timing the boost will peg a 60psi gauge

[cummins724]

Originally Posted by 01CumminsSport

with the electronics off i will do just over 40psi and with the edge back on and i using it for just timing the boost will peg a 60psi gauge

So with the 5* added timing, you are saying that you have less boost only when staging? You have more boost in high rpm? Just making sure I understand.

[TURBOLVR]

That makes sense. when mechanically adding timing, the box adds too much for the bottom end, but is adding the extra needed on top that wasnt previously available.

[cummins724]

Originally Posted by TURBOLVR

That makes sense. when mechanically adding timing, the box adds too much for the bottom end, but is adding the extra needed on top that wasnt previously available.

Thats what I was trying to clarify. If that is the case, it proves that moving 5* advanced is actually adding additional timing up top & taking away from low end.

[01CumminsSport]

Originally Posted by cummins724

Thats what I was trying to clarify. If that is the case, it proves that moving 5* advanced is actually adding additional timing up top & taking away from low end.

yes that is what it is doing, but what we dont know is if it is still adding that extra 5* timing up top or is the computer backing it down some, but either way there is still more timing up top than there was before adding the 5*

[TURBOLVR]

Think of it like a clock. If you have 25 mins of timing @ 12 base and then move base to 1 oclock, add that same 25 mins and it now goes to 30 but cant be less than 1. If the computer is reading off the cam sensor that you didnt move, it wont know the difference and cant correct for it.

[cummins724]

Originally Posted by TURBOLVR

Think of it like a clock. If you have 25 mins of timing @ 12 base and then move base to 1 oclock, add that same 25 mins and it now goes to 30 but cant be less than 1. If the computer is reading off the cam sensor that you didnt move, it wont know the difference and cant correct for it.

Thats what I was thinking up until 01cumminssport said that his truck turned 4300rpm even before moving the gear 5*. If he didn't gain any rpm, the change is useless.

[cummins724]

Originally Posted by TURBOLVR

Think of it like a clock. If you have 25 mins of timing @ 12 base and then move base to 1 oclock, add that same 25 mins and it now goes to 30 but cant be less than 1. If the computer is reading off the cam sensor that you didnt move, it wont know the difference and cant correct for it.

He did move the cam though, he has a 6* keyway.

[01CumminsSport]

correct me if im wrong but on the 01's there is no crank sensor so if i advanced both of them about 5-6* then the motor thinks i didnt do anything but on the trucks with the cranksensor and a cam sensor they will go into limp mode since it is seeing them at a different location instead of being in sync. If thats true then i am doing 29* total timing, and i wasnt able to turn more rpm (electronics) but there is more power up there and i did dyno after i did the timing change and there wasnt much of a drop in power from peak all the way out past 4K

[cummins724]

Originally Posted by 01CumminsSport

correct me if im wrong but on the 01's there is no crank sensor so if i advanced both of them about 5-6* then the motor thinks i didnt do anything but on the trucks with the cranksensor and a cam sensor they will go into limp mode since it is seeing them at a different location instead of being in sync. If thats true then i am doing 29* total timing, and i wasnt able to turn more rpm (electronics) but there is more power up there and i did dyno after i did the timing change and there wasnt much of a drop in power from peak all the way out past 4K

Good point. The 98.5-2000 have both sensors and the 01-02 engines just have the Cam sensor, no crank sensor.

[01CumminsSport]

i might give 10* a try tomorrow and see how it is seeing how i have have nothing on the schedule at the shop i fugured i might as well try some new things with timing, see if not have the crank sensor will let me add even more timing

[cummins724]

Originally Posted by 01CumminsSport

i might give 10* a try tomorrow and see how it is seeing how i have have nothing on the schedule at the shop i fugured i might as well try some new things with timing, see if not have the crank sensor will let me add even more timing

Thats the spirit!!!