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LPG Home Made

2K views 7 replies 5 participants last post by  9297oldram 
#1 ·
I am looking for something on the truck that will tell the LPG solenoid to open to let around 4 psi LPG vapors into the inlet side of the turbo. Boost will not work, Because when the exhaust break kicks in the boost goes up over 5 psi (you do not want LPG going into the turbo when you are trying to slow down).
Just cruzing flat highway 55 mph around 4 to 9 psi boost. Just goes up fast when on any hill or if you speed up slowly.
36 psi max on the boost stepping into it.

Fuel PSI would work. Watching all of the gauges when driving, as soon as I step onto the go pedal, Fuel PSI goes from 4,000 - 6,000 up to 8,000 psi and climbs up to 26,000 PSI when you lay into it. OR on a BIG HILL PULLING RV. Let off and it drops like a rock to 7,000 to 5,000 PSI. Does not matter if the exhaust break is turned on or off, (OFF it still kicks in on the top gear you are in when slowing down. ) (on, it hits all the gears)

So I am thinking of getting a PSI Switch that has a range of 0- 30,000 psi and can be adjusted to the 8,000 psi for the contacts to close. sending 12vdc to the relay that will open the solenoid valve on the LPG tank regulator. I can mount two 20#'s or one 33# vapor tank(they are rare tanks) that is made to lay down on its side. (most side mount are liquid LPG tank for fork trucks that lay down) I don't need liquid. I most likely would use an 3/8 inch line to the intake.
BUT where to tap into the fuel system to get that PSI. I did put in fuel shim's to raise the fuel dump PSI to 26,000. some put plugs in there to let it keep climbing. But I want to only let it max out to 26,000 psi. so where else could I tap into to get that reading????

( I fill propane bottles for my living 250 to 300 a day.) (Propane is cheap from where I work. Boss/owner asked me if I had propane on my truck. He told me to do it and we get bottles filled for free. No big 100# or home tanks please) I fill his and the drivers BBQ and heater bottles all the time.
So I need to get this put on.
to save on Diesel fuel.

What's you think?
 
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#2 ·
you can not use a hobb switch for 10k psi

raise the propane injection to 6 psi issues solved
 
#3 ·
still don't have something to tell the propane when to turn on. By boost or fuel PSI or I have to my a switch in the cab. I know what to use and how propane gets to the eng. just need to know what others or using to know when to turn on propane to the intake? OR are all of you just flipping a switch and turning it on when you drive and off when you hit the breaks?. Can't dump propane into the intake when you are trying to slow down.
 
#4 ·
ok found my answer, looked on ebay for around 375. I can get a kit and it works on Neg psi on the intake. When the turbo pulls air (spools up) The Reg starts dumping Propane into the system. SO when the turbo (exust break) kicks in. it will not be pulling air and then the propane system will stop dumping in propane.
 
#5 ·
Last post was almost a year ago, so might be too late for your setup. Another way might be to have a limit switch on the throttle position. It can kill the lpg when throttle is closed. I'm just thinking about lpg for my truck and that's a problem that I haven't considered. I don't have an exhaust break yet, but was planning on one. Boost seemed the perfect trigger for lpg. I want to have lpg at low boost so when I'm on the freeway at low boost, I'm still getting my milage booster flowing, otherwise it's just a power adder. I'm curious how the neg prsr switch is working for you.
 
#7 ·
Old post I know.....
How about a throttle activated micro switch wired with an over ride on/off switch.
Much like on a nitrous system, no throttle input, no propane.....works for me.
 
#8 ·
You could use a adjustable boost switch like what is used on WM systems.
 
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