2TG Eletric fuel pumps

[merc-blue]

G'day,
I have just finished welding up a nice Surgie and have my VL pump and lift pump ready to all go into the TA22
my question is can i wire the pumps off the ignition switch? i was thinking of running the VL pump off a independant switch (power taken from the switching side of my isolator) and the lift pump off the ignition i just dont want to be frying my ignition switch from pulling to much power through it

Cheers for any info

[BeRad]

it should be ran through a relay. activated by the ecu.

[merc-blue]

pity its a carbied engine origionaly run from a mechanical fuel pump

[BeRad]

You put in a relay and switch it from the ecu.

[merc-blue]

how about you read the post!
Its a carbied engine, NO ECU
it origonly had a mechanical fuel pump (driven off a dummy cam shaft)

I am installing a different fuel system to cope with the engines demands,
i just want to know what other people in a similar situation have done, have try run both pumps off the ignition or off other switches or off a relay off the ignition etc

please not there is no ecu in the car, the closest i get to any sort of computer is the indicator stalk!

[BeRad]

it confuses me your using a vl pump then?, the vl pump being high pressure and for efi engines. thats why i assumed it was now efi, therefore needing an ecu.


maybe im missing something haha

[o_man_ra23]

and your running a surge tank and EFI high pressure pump because?? oh, you want to destroy your carbie's needle and float?? the carbies arent meant to take that kind of pressure... yes thats right EFI pumps are for EFI, not carbies. The best way would be to forget the surge tank (no benefit to carby), and just run the lift pump straight to the carbies. This will be your best option. As for switching, use a relay like every manufacturer, auto sparkie and backyarder does.

Cheers, Owen

[BeRad]

haha what i wanted to say but thought i was missing something so didnt want to look like a wanker if i had indeed missed something.

[merc-blue]

the VL pump and a MALPASSI regulator will be run,
bassicaly the surge tank is used to keep a supply of fuel avalible in all situations eg around a long fast corner.
this isnt a street car its a race car,

if you want more explination and diagrams i can supply them (although my drawing skills arent great)

EDIT: heres pictures

This is a very common fuel setup on carbied race cars, i just want to make sure it wont fry the ignition switch

[o_man_ra23]

how about you read my post!! carbies arent meant to take 40psi of fuel pressure up their arses (which is where a VL regulator will be set). My RA23 never had problems with fuel surge, even when I ran the EFI with in tank pump. Put a floating pickup in, and youll never have a problem. Model aeroplanes use floating pickups for when the travel upside down.

If you continue to put this extra weight in your car, and draw extra current from your alternator, and over pressurise your carbies, you wont be much of a competitor in a race.

Cheers, Owen

[merc-blue]

im not using a VL regulator sorry that was abit unclear

[BeRad]

an aftermarket fpr would be able to drop it low enough for carbies maybe, but i dont see the point, why not use a carbie pump?

[brett_celicacoupe]

your using a VL pump with carbys?!?!

sounds like a recipe to burn the car to the ground

[o_man_ra23]

still extra weight which is unneccesary and expensive

also you have the pump running its arse off trying to pressurise, pulling excess current from the alternator, which is pulling excess HP from the motor, when you could run a single pump, at a much lower current, with a floating pickup, and do a the same job at less cost with less weight and less engine drag.

your not using logic.

Cheers, Owen

[merc-blue]

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

EDIT:
brett thats y you use a regulator to drop it back down to a carbie suitable pressure
Ill have a look at a floating pickup,

Really if i was worried about a extra 2Kgs i would go on a diet