PRINCETON_JAKE
New member
Why not eliminate all the controls? Gut the psg by wiring the timing solenoid to a potentiometer, and hard wire the fuel solenoid to your pedal eliminating the ecm, psg, and all monitored sensors
VP44 Standalone ECU Project
- Thread starter zachu812
- Start date
wwentzler
New member
That's not how any of this works.
PRINCETON_JAKE
New member
Explain then, because from my knowledge (not saying I’m right) the only two electrical parts are 2 solenoids, 1 controlling timing, and one controlling fuel into the head. They are controlled by the “psg” which is told what to do via the ecm which is told what to do via numberous sensors and inputs.
Tell me where I’m wrong, because if that’s correct there’s no reason the timing solenoid couldn’t be run off a potentiometer to manually controll timing in a controllable but fixed timing, and the fuel solenoid could be controlled by eliminating 99% of the BS with a simple home made controller
zachu812
New member
The timing solenoid controls the timing piston by regulating the fuel pressure that moves the piston, to regulate pressure the duty cycle of the solenoid is varied by sending it a PWM signal from the PCM.
And for the fuel solenoid similar idea, its not something you can give more power and get more fuel. The solenoid has to be opened at a very precise time and for a very precise amount of time. There is only a certain window of time in which the VP can inject fuel to a given cylinder but as long as you're within that window you can control how long the fuel solenoid is open which controls the amount of fuel injected.
99GreenCummins
That guy....
But I'm assuming something like this will be competition only and why's it important at that point?
wwentzler
New member
Because that's the only advantage of a vp44 over a ppump. (Which is a big advantage btw) Dynamic timing is probably the single thing that makes CRs so much better than anything else.
joefarmer
MR. Supreme Overlord
Maxim has several that may work. MAX9924-27 is meant for VR, but it's worth a shot. BrickRPM has a module with a MAX9926 on it if you don't like to hand solder 0.5mm leadspacing.
zachu812
New member
The dream is for a VP to be able to run low timing so it can spool a decent sized charger then ramp up timing and drive the charger hard past 4k.
Looked at the datasheet a little closer, thought they were for zero crossing sensors only but it looks like you can adjust the bias too. That might be an option.
PRINCETON_JAKE
New member
That could all be done off a boost reference sensor
I love how some of you think a vp has an advantage over a p7100 lol. Even if you design and build this stand alone that isn’t going to do crap for hp, you still need a $2000+ modes pump and even with that you’re still extremely limited on fuel capabilities compared to a p7100 or common rail...
You’d be a lot better off going to dual VP’s if you want to give a vp a chance I’m hell. Run them all off stock electronics. Set them at standard timing with one off a cog/blower belt, build an adjustable drive gear that varies the timing on the 2nd pump to advance or retard that pump to change timing, and better yet it would widen the pulse by over lapping/extending the pulse of the 2 pumps.
Think on that for a minute...
zachu812
New member
The VP does have an advantage over a P7100 in terms of driveability, packaging, and fuel consumption. In terms of all out fuel delivery a VP won't ever be able to touch an inline pump or even common rail, I don't expect to change that but I do think we can bridge the gap a little bit with electronics that will do what we tell them. If you're a Ppump or CR fanboy that's cool too, there's plenty of other threads for you to enjoy.
zachu812
New member
Got home from a month long business trip last week so I’ve been trying to catch up the past few days. Spent a little time on the project and got a circuit built, just a simple comparator. Gonna borrow a scope from the office next week so I can see if everything is working.
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Mooner1
New member
Exited to see where this thread is going. Admittedly this level of electrical engineering and circuit building is way over my scope of knowledge, but that is one reason I’m digging it. Always cool to log in and learn a little. Loved my VP in my ‘99 for a daily driver, put a FASS on it and it never let me down..just hated the way it drove when the electronics/pump started going haywire.
RascalMafia
heyyyyyyy girrrrrrrl
Not that I would ever buy another VP truck, but this is one of the best hardcore tech threads I've seen here in a while.
zachu812
New member
My understanding is that the electronics limit the fueling before lack of fuel is an issue, hopefully we'll find out one of these days.
Been busy past couple weeks, still getting caught up and trying to get the truck ready for an upcoming hill climb. Gonna try to pick things up again this week.
khaoskustoms
New member
This has been done with dual p-pumps already. It was a pretty cool setup.
There are a couple things at work.
1. design of a pump, a rotary pump looses it's ablity to pump as rpms rise.
2. on stock ecm programming the ecm goes into runaway protection mode above 3500 rpm.
3. limit of the fueling command structure prevents higher duration without wiretap.
I do believe good fueling is possible at ~4000 rpm with a VP44. However the pump is not exactly efficent at that rpm. no way around the design limitation of the pump.
If you remove #2 from the equation you should be able to gain a good bit of power at 3k+ rpm. Remember that ~%75 of fueling comes from canbus message from the ecm fueling rather than wiretap. When you hit 3500 rpm %100 of canbus fueling stops, therefore you have to try and keep fueling up using wiretap only. This is big reason why the power "falls off" so fast after ~3200-3500 rpm.
Now if you control the solenoids directly you no longer have to work within the bounds of the ecm -> vp44 communication protocol. You can command as much duty cycle from the solenoid as you want and you can ask for that duty cycle without worry about running out of room in the communiation structure.