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Location:
Melbourne
Registered:
October 2003
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Surge Tank Operation
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Tue, 10 February 2004 10:58
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Hey I've just installed my 1.7lt Surge tank and Low pressure Lifter pump.
The surge tank has two fittings, a top and bottom.
I have steel line/low pressure hose from main tank to lifter pump >
Injection hose to surge tank top fitting>
Injection hose from surge tank lower fitting to hi-pres pump>
High pressure pump to fuel rail via Hose/steel lines.
hose/steel line to main tank via.
So now that I've explained my setup, my question is how great is the need to have the fuel rail returned to the surge tank?
Is there any danger to the pumps by running the setup without an overflow from the surge tank to the main tank?
My concerns are pressurising the surge tank too much, thus blowing a hose. Albeit a low pressure lifter pump. Also having the surge tank run out of fuel at high RPM and creating a vaccum in the surge tank - leading to air being pumped through the main pump.
I am sure all this could be fixed by adding the extra to fittings, but if its going to cause a major problem soon - I wont drive the car untill I get it done.
Cheers
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I supported Toymods
Location:
melbourne
Registered:
June 2002
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Re: Surge Tank Operation
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Tue, 10 February 2004 12:19
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ok, here is what you do, assuming that your low pressure pump is up to the task of supplying the engine with at least as much fuel as it will ever need.
run the return line directly to the main fuel tank, this will solve all of your problems.
so, your setup will be (in order of where the fuel goes)
low pressure line from tank to lifter pump
low pressure line going from lifter pump to surge tank
line going from surge tank to high pressure EFI pump
high pressure line going from high pressure EFI pump to fuel rail
return line going to main tank.
i'd use a surge tank with all 4 fittings, or just use an internal surge tank and a swimmer pump, as it simlifies things by removing a pump, and "something that isnt there can't break" but the method described above should work fine.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Surge Tank Operation
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Tue, 10 February 2004 12:22
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currently you have fuel going
LP pump
surgetank
MP pump
fuel rail
fuel tank??
what you need to MAKE SURE is that the LP pump flows more (with no back pressure) than your HP pump can (with fuel rail back pressure, ie hooked up to pressure regulator with vac ref off)
this way, the surge tank will always have a little bit of pressure in it...
ideally, your LP would either be internally regulated, or you would have a carb type pressure regulator set to maybe 3Psi, that way the surge tank is always at that pressure.
if the HP pump with fuel rail pressure flows more than your LP pump, then you are in trouble.
the other option is:
run LP pump with no regulation, to the surge tank.
Surge tank to HP pump, to fuel rail, and back to the surge tank.
THEN, have an overflow line from Surge tank to main tank.
this way the fuel is recirculated aroudn the fuel rail without going to tank, BUT since cool fuel from main tank is always pumped at the LP pumps maximum, into the surge tank, it mixes and cools the fuel...
also means that the amount of fuel retuning from the surge tank overflow, will be equal to the LP pumps maximum flow - what the engine consumes, and you will never have the HP pump run dry..
well, thats how i'd do it 
actualyl, i'm putting an in-tank pump into a surge tank, with the LP set up as above.
Cya, Stewart
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Location:
Melbourne
Registered:
October 2003
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Re: Surge Tank Operation
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Tue, 10 February 2004 19:20
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Thanks guys. But maybe my setup wasn't explained properly because what "shinybluesteel" said is the setup I already had. And what "oldcorollas" suggested is what I suggested in my first post. Thanks for the interest guys but I'm wanting to know of potential problems running the setup as it is currently.
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Location:
Perth
Registered:
August 2002
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Re: Surge Tank Operation
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Wed, 11 February 2004 02:23
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Sorry to chance subject but where have you put the surge tank on the TA22. the seems to be bugger all room!
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Surge Tank Operation
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Wed, 11 February 2004 06:22
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| oldcorollas wrote on Tue, 10 February 2004 23:22 |
what you need to MAKE SURE is that the LP pump flows more (with no back pressure) than your HP pump can (with fuel rail back pressure, ie hooked up to pressure regulator with vac ref off)
this way, the surge tank will always have a little bit of pressure in it...
if the HP pump with fuel rail pressure flows more than your LP pump, then you are in trouble.
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and theeen????
want me to measure it for you as well  
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Location:
Melbourne
Registered:
October 2003
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Re: Surge Tank Operation
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Wed, 11 February 2004 10:13
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ok yeah sorry oldcorolla. I realised that. Cheers
sebta22, I'll take a pic and email you. But I have it on the drivers side in the boot, mounted to the same holes as the fuel tank itself. looks pretty neat !
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Location:
Rocklea qld
Registered:
February 2003
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Re: Surge Tank Operation
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Wed, 11 February 2004 11:11
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sorry to hijack but im trying to figure out my surge tank ideas and was wondering if i cut my fuel tank in half and baffle it is there any need for a surge tank.
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Location:
Perth
Registered:
November 2002
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Re: Surge Tank Operation
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Wed, 11 February 2004 11:13
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hey if you have no return from the surge tank doesnt that mean any air sucked by the LP pump would have to go through the HP pump and fuel rail on its way back to the main tank?
does that defeat the purpose of the surge tank?
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Surge Tank Operation
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Wed, 11 February 2004 14:13
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hmm, good point... althought he LP pump will provide some pressure, it might be better to have at the minimum, a vent line going from top of surge tank to main tank... so that any air can bleed out..
altho the air will be at the top of the ST, it could build up...
this could be an issue on hot days when the fuel in the ST vapourises.. the vapour has to go somewhere, and it aint going back thru the LP pump..
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