2TG Eletric fuel pumps

[brett_celicacoupe]

a high pressure (efi) pump is not neccesary. go buy a low pressure high flow pump and it will do the job properly.

i dont even think a regulator can regulate that low because there will be so much damn fuel flowing in, the floats wont be able to resist the flow to cause any pressure.

why risk your car catching on fire just for a few bucks?

[o_man_ra23]

OK WELL,
Fistly the reason for the surge tank is to keep a constant supply of fuel, say around the first corner of phillip island the fuel can move away form the pickup, with a surge tank which is always full to the brim if the fuel in the main tank does move away from the pickup you still have 2L of fuel to use by which time the corner has finished and teh lift pump will top up the tank (faster than ur can burn it)

Reason for a EFI pump and carbie regulator, high pressure low volume incomming line will move fuel faster that the reverse bassicaly although a big return line is needed as the reg will turn high pressure low volume into low pressure high volume, bassicaly the reason for a EFI pump is same as we dont keep Gas stored in giant low pressure tanks but smaller high pressure tanks

First part, read for a third time that a floating pickup will do the same thing as a surge tank when you are looking at carbies. Their floats will hold enough fuel for small jitters.

Second part, you keep gas stored at high pressure because GAS compresses, and you can store more of it in a smaller space. why dont you store petrol in a pressurised fuel tank?? oh, maybe its because LIQUID doesnt pressurise!! A HVLP pump will flow just as much fuel as a LVHP pump. notice how the pumps for 1000hp supercharged carbied V8s run at ~9psi?? not 40??. So when your regulator fails, you will not only have to replace the regulator, but also rebuild the carbies from the ground up. Smart eh??

Re-read your highschool physics books.


Cheers. Owen

[o_man_ra23]

a high pressure (efi) pump is not neccesary. go buy a low pressure high flow pump and it will do the job properly.

i dont even think a regulator can regulate that low because there will be so much damn fuel flowing in, the floats wont be able to resist the flow to cause any pressure.

why risk your car catching on fire just for a few bucks?

Brett, its costing him more to do it the wrong way. Seems we are arguing with a 4yr old

Cheers, Owen

[merc-blue]

Ill do some research into a floating pickup, and see what happens,
as for a 4yr old, pfft you can have your opinion, but from what i have seen installed and been told that the system im suggestiong is the most common and popular fuel system

[o_man_ra23]

why expend a lot of energy to pressurise the fuel then let it all out?? if you are running large return line, then you obviously are pumping too much fuel.. And whoever told you that its the same principle as compressing gas should be taken back to kindergarden and told about compression. Otherwise your brakes wouldnt work.

Cheers, Owen

[merc-blue]

Owen, nobody said anything compression of gas, it was more a analogy forget i said that,

[o_man_ra23]

bassicaly the reason for a EFI pump is same as we dont keep Gas stored in giant low pressure tanks but smaller high pressure tanks

how is this an analogy even close to correct?? gas gets stored in smaller high pressure tanks to save space. EFI pumps flow at high pressures to create a vaporised mist when the fuel leaves the EFI Injectors. their not on the same field, nor the same game, not even the same sport!! (to hack a quote from pulp fiction). If your going to use an analogy, make sure that what your saying is correct, even close to factual. Gas compression actually leads to heat problems, just look at the cooling stacks of any gas company (BOC etc). Do you want your fuel served hot to increase detonation, decrease engine life and decrease performance??

You really need to go back to physics basics if you dont want this racecar of yours to blow up.

Cheers, Owen

Oh yeah, by using an analogy involving high pressure gas, you indirectly referenced gas compression

[jonra23]

I am not going to get into the argument about choice of pumps!!!!

Run them both off a relay switched by your ignition switch, drawing power from your master switch.

regards
jon

[styler]

wow its getting hot in here lol

anyway i have a 3tg hybrid, running twin weber sidedraft dcoe45's.

its got a low pressure high volume pump, 8 psi, uses a regulator set at 3.5psi, cant remember the flow rate but it was decent. both carbies feed off the same line. some people dont put a fuel return line in the system at all and some people do use a fuel return. i would probably use the return line and put in some sort of pressure relief valve between carbies and fuel return line.

its a carter inline fuel pump $80 from supercheapauto including mounting brackets and the 5/16 inch rubber hose barbs (5/16 off the top of my head). its a self priming pump and it is a lift pump too, only a small height of lift 10cm or so, but its just lower than my tank anyway so it doesnt matter.

i have a generic carby fuel filter mounted between the tank and the pump intake.

my pump was originally connected to one of the cars accessories wires but i would recommend that you connect a suitable amp rating automotive relay (cos auto relays are cheap) as has been said, activated by ON. the pump should be less than 10amp id say.
you can also wire the relay's activated wires through a kill switch if you want too, sometimes a hidden switch is used so it acts as an immobiliser when people steal the car and the switch is off (the carbies run out of fuel pretty quick).

there is a long thread on the old toymods forum covering this topic too

peace out!

[c2888]

I used a facet solid state pump when my 4ag had twin dells, no reg
ran a champ, powered off the ignition, in hindsight would've been better to switch it with a idiot light and relay, so when the engine stops, so does the pump.

There was enough fuel in the carbies bowls for my dad to get to the end of the street, he asked me where the kill switch was after pushing it home

Dan

[andurils_sheath]

AFAIK regulators work by allowing a certain amount of fuel through the return line when the fuel reaches a set pressure, not by depressurising hi-pressure fuel. Therefore your model of pressurising fuel then it depressurising it after it has reached the carbies is flawed. Basically what youll end up with is a low volume pump running below its optimum pressure and basically flowing like crap coz there is no restriction to allow the pressure to build up to a reasonable level. Youll end up with a pump that flows like crap. Your better off just getting a low pressure hi volume pump that you can run in the boot. There is no need for a surge tank as the float bowl is well big enough to supply fuel through a turn. The need arrises for a surge tank in a efi setup because the fuel setup has no float bowl.

If youve already put in a surge tank i guess you could run a carby pump before and after the surge tank. However there will be no difference to running a single pump. My reccomendation would be to run just a hi volume carby pump from the boot and selling the surge tank to someone who can use it. Youll save yourself money effort and weight, as well as finishing with a product that works welll.

Cheers.

[STR8 2.8]

fyi. i dunno if you really care but from my experience i have found facet pumps to be quite noisy. maybe ive just had cheap ones but yeh. i know if i was lookiung for a lift pump it wouldnt be stupidly noisly (eg facet pump)

[c2888]

oh yeah, forgot to metion the massive clatter from the facet.
at least you know it's running!

Dan

[o_man_ra23]

took a while for you people to start talking. Andurils_Sheath, your post is what I was trying to get at... just couldnt find the words. Thanks for making that one clear. C2888, your dad must hate your car now Again, the float bowl size is what I was trying to get at, thanks to you for providing an example for that. Rep to both of you. str8 2.8, the noise of a facet pump can be reduced with proper mounting and enclosing, there is a thread in the tech section which has some good methods of doing this.. cant remember the name of the thread, but it also had EFI pump mounting methods involved.

Cheers, Owen

[shelldrake]

Regarding your fp connection. you can use a relay triggered from the oil pressure switch. You lose oil pressure, your petrol stops pumping. I like stylers return line regulated idea.