I have developed a theoretical way to increase the fuel available to the VE for debate. I dont think this method has been proposed yet.

Since most of us have non functional shut down solenoids this might make sense. What if the solenoid was removed and a fitting was machined to screw into the pump at this location. The fitting would need a one way check valve to prevent backflow. An electric fuel pump with a seperate fuel feed line and return would supply fuel to the port (which directly feeds the high pressure piston) under high demand situations by use of a WOT microswitch wired in series with a hobbs adjustable pressure switch.

I believe if done correctly this may be how to lay down really big numbers with the little rotary pump.

What do you think?

 

I thought about something similar but with an inline fuel pressure regulator. I like the idea of only activating it when needed. Hopefully some of the more experienced guys will chime in.

 

One could also use a raising rate fuel pressure regulator so as boost increased so would fuel flow. This would allow you to not run the throttle solenoid. Just set it to keep fuel low untill boost was say 20 psi and then ramp up the flow untill max boost.

 

Can't run it in where the fuel shutoff solenoid is because that area is at case pressure. Case pressure runs anywhere from 25-100 PSI depending on RPM and load.

Here's what I'm going to do about fuel pressure. I'm going to run a second fuel pickup in the tank to a Walbro pump, then a filter, then a bypass regulator set to 15 psi or so, then run that straight in the banjo bolt on the clean side of the stock filter head. Power for the pump will be controlled by my valet switch, so the "backup" fuel system will only be activated when I want to play. This way the truck will not be dependent on an electric pump to run. You could also have it triggered by a boost switch, say 15 or 20 psi and it kicks in. I'm gathering parts now and I'll try to take a bunch of pics while I do it.

 

I'm liking that plan, Dave! Do you think there will be some benefit to upping the line size from the clean side of the filter to the pump? Seems like big sticks and big head pumps like volume more than anything...

 

It might be a good idea to get rid of that banjo eventually, but 15 psi can push a lot of fuel through that line. I don't think that line will be a problem.

 

Anyone ever mess with a variable overflow? Is it possible that the factory o/f banjo can get confused or overcome in high flow/hp applications, resulting in a drop in case pressure? Seems like Stomp messed with this...

 

Yeah, Stomp said he put an adjustable regulator on his. Not sure if that was a tuning tool or a permanent solution to something, though.

 

What if I said there are electric fuel pumps already being manufactured that push 120 PSI? I had taken case pressure as a consideration. This just might be the next best thing to adding a second injection pump that fuels under load.

While were on the subject does anyone know if larger fuel lines were ever made or can be made from the piston pump to the filter and from the filter to the VE?

 

You'll need a filter that can handle the pressure, but it would keep you from losing timing.

You can make bigger lines for the pumps. Use -6 AN stuff. Places like Summit carry all kinds of adapter fittings.

I've revised my plan, I'm going to run the Walbro into the dirty side banjo with the bypass on the clean side. We use the same filter as the 2nd gen 12 valves, so it will have no trouble handling the pressure needed to get 15 psi on the clean side.

 

I just cheated, I run a mercedes cold start diesel inj, it feeds in right before the water nozzles.

 

Tell us more of this mercedes cold start injector!!!!
Peter.

 

Mercedes diesels use a non pulsing inj to assist in cold weather starts. I simply made a water/meth inj system that uses diesel instead of water. Since the inj doesnt pulse as one in a cyl it only needs about 20 psi to atomotize the fuel. My first design water controler controls the amount of pressure the pump puts out so it doesnt come on full blast. I dont know what its flow rate is at 125 psi but it will definatly get your attention. I dont run it at the moment, my turbo is a stock hc1 and theres no air for the added fuel, for time being.

 

Just what i was thinking,,,
vw and audi use the same cold start injectors i believe,,
on my 89, with the inj pump turned way up, 3-4 turns on fuel screw, in 4 th-5th floored, I haze very little, It seems to me that i could use more fuel, I am still running the baby H1c and water/meth, I am up to 35-36 lbs boost, and no barking,,,,,, Mabey i need to take a trip to the bone yard and pick up some goodies for the dodge!
Peter.

 

You could run this kit and find out. Pull the adapter fitting out of the VE and it'll bolt right in.

http://www.glacierdieselpower.com/pr...?pf_id=9852BLK

I'll be incorporating it into my dual fuel system, I ordered all the parts tonight. Some from Glacier, and a bunch of stuff from McMaster-Carr. Hopefully by next weekend the fuel tank will be light enough.