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Location:
Adelaide and Queenstown T...
Registered:
September 2002
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Lift pump without Surge tank for EFI
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Mon, 22 September 2003 01:08
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Going on from the 18RGEU intake pipe thread
I already have an electric facet pump for the carbie setup.
The EFI pump I have looks like it will be hit by the diff if I mount it in the same place as the facet pump.
Would I be able to mount the EFI pump in the engine bay if I have the facet pump pushing fuel to it anyway.
It would effectively be the way others have described their engine bay mounted surge tanks, except without the surge tank.
Then the standard pressure regulated return line from fuel rail to main tank.
I would have to watch the fuel level etc but that is the same as if I was just mounting the EFI pump externally anyway.
What do you think. It will also make it easier to swap between the carbie and EFI setup (if I wanted too?????????).
Does anyone know if you can use a RA65 internal EFI pump externally or does it have fuel come out the sides when the pressure gets too high?
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Registered:
June 2002
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Re: Lift pump without Surge tank for EFI
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Mon, 22 September 2003 01:29
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I don't think a pump supply the EFI pump is a great solution here. I have mounted a pump in the engine bay and it ran that way for two years without two many problems ( well no more problems than you would have whenever you don't run a surge tank). The trick is to moun the pump low enough in the engine bay so that is below the bottom of the tank. This way the pump will be gravity feed (until the tank is low and you go screaming around a corner).
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Location:
Adelaide and Queenstown T...
Registered:
September 2002
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Re: Lift pump without Surge tank for EFI
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Mon, 22 September 2003 01:47
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In a RA28 the pump can never be gravity fed because the fuel line comes out of the top of the fuel tank.
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Location:
Brisbane
Registered:
May 2002
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Re: Lift pump without Surge tank for EFI
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Mon, 22 September 2003 02:23
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Not true. The pickup is at the bottom of the tank, so as long as the pump is below the level of the pickup it will be gravity fed thanks to the syphon effect.
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Location:
Adelaide and Queenstown T...
Registered:
September 2002
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Location:
adelaide
Registered:
April 2003
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Re: Lift pump without Surge tank for EFI
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Mon, 22 September 2003 06:42
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you could muck about per the above or you could just get hold of a surge tank. it will be infinitely better, and if you or your mates can make one up it should cost less than $20
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Location:
Adelaide and Queenstown T...
Registered:
September 2002
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Re: Lift pump without Surge tank for EFI
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Tue, 23 September 2003 00:23
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The problem with a surge tank is where to put it. I don't want it in the fuel bay for safety reasons and you aren't allowed to have fuel in the cabin so in an RA28 you are limited by where you can put it.
A nice simple external pump seems the easy way to go and is it really that hard to keep your fuel level above 1/4 of a tank?
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Location:
Brisbane
Registered:
May 2002
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Re: Lift pump without Surge tank for EFI
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Tue, 23 September 2003 01:05
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People usually mount the surge tank under the car in liftback setups. Another option is to convert to an in-tank setup; I'm sure if you bought an RA65 tank or similar you could find a way to mix'n'match components.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Lift pump without Surge tank for EFI
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Tue, 23 September 2003 03:40
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you can use a low pressure pump to feed the high pressure pump, but you have the be _absolutely sure_ that the low pressure pump/s provide more fuel than the high pressure one. you can check this easily...
pump fuel thru the high pressure pump with no outlet pressure, or maybe with the pressure regulator in place, and measure the output.
now take your low pressure pump/s and do the same thing. as long as the low pressure provides maybe 10% more than the high pressure, you are golden.
you can mount multiple low pressure pumps in parallel to do this, and even have one taking fuel from each side of the tank (partially negates surge).
or you could just do an intank surge pot, or have external surge tank...
Cya, Stewart
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Lift pump without Surge tank for EFI
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Tue, 23 September 2003 03:42
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oh, and make sure the battery and switches are a long way from the fuel vapour.. not good to blow yourself up for the sake of science 
Cya, Stewart
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Location:
Adelaide and Queenstown T...
Registered:
September 2002
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Re: Lift pump without Surge tank for EFI
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Tue, 23 September 2003 04:35
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at $38.50 a pump I think I will just try in the engine bay for now and when it breaks I will then assess what to do with it, from the sounds of it the pump shouldn't be too upset as long as it is low down, and before the main fuel filter (because these cause too much resistance???).
Considering after all this I am only driving the car for 4 months before I go to japan for a year I will just hope it lasts long enough.
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