14 replies to this topic

[hatchssv8]

I have a few pics you may be interested in. I will try and host them buy 6 pm today.

Set up is for injected motor

Cheers, Max

[Toranavista]

This should keep you off the streets
http://canberratoran...o/droptank.html

[ls2lxhatch]

lx304hatch,

I will be interested to see what you come up with. I have a Brown Davis tank and was planning remove the plate over the spare tyre recess. Fit the sirl pot inside and then replace the spare tyre plate with a flat plate which should leave enough room to mount the swirl pot pump and EFI pump.

If you are building the tank from scratch then you could look at fitting the pump from a VZ LS2. The standard Brown Davis tank is not deep enough by about 20mm and does not have any clearance above the tank. The VZ pump has a minimum depth of 240mm and needs 40mm clearance above for fuel lines. The VZ pump is around $250 from Holden including swirl pot and fuel sender. You can buy a weld in mount ring to suit from Castle Auto Elec for $120.

http://www.castleaut...igen3lhlxuc.php

[Dangerous]

Gee ............It would be a shame if they only made one .............. HINT HINT

[ls2lxhatch]

sorry to disapoint you im just running a pretty well stock vn v8efi and just thought that i want a drop tank and few guys at my work said they could make it if i get the plains and gear, was gonna put a stock vn v8 pump into the tank and a stock vn v8 out tank to suply the motor

It is still worth considering moving the swirl pot into the tank instead of the boot.

If you need any additional measurements or pictures I will have my Brown Davis tank out of the car for the next couple of weeks.

[ls2lxhatch]

don't brown davis make drop tanks with, surge tanks already inside? im pretty sure thats what they told me last time i gave em a call.....they were only a couple hundred bucks dearer than the standard drop tanks. i should have a surge tank in my hatch and am seriously considering buying another brown davis tank to replace the one i curently have.....
instead of mounting a seperate thing somewhere and runing more fuel lines etc.

cheers

I bought a Brown Davis fuel tank with the 1/2" pickup and swirl pot which cost an extra $150. At the time I ordered the tank I was told the swirl pot was suitable for EFI and I did not know any better. A swirl pot and a surge tank are two different things.

The swirl pot in the Brown Davis tank is a set of baffles with a 1/2" pickup in the middle. The swirl pot is filled by gravity under normal conditions and the baffles slow down the emptying of the swirl pot during g-force events. When you pump fuel out of the swirl pot there is no return line back into the swirl pot instead the return line is via the standard fuel pickup.

A surge tank is typically a tall one litre tank with a pickup at the bottom, an input near the top and an overflow at the top. Fuel is pumped into the surge tank from the main tank using a low PSI fuel pump. G-force events have little effect on the surge tank because of the tall design. When the you pump fuel out of a surge tank to the engine any excess fuel is returned to the surge tank. Any excess fuel from the lift pump in the surge tank is returned via the top pickup to the fuel tank.

The typical EFI setup is to pump fuel at a constant flow rate and high PSI to the engine and any excess fuel/pressure is bleed off by a regulator and returned to the surge tank. If you were to use just the swirl pot in a typical EFI setup the swirl pot would be emptied in a few seconds during G-force events by the EFI pump as the excess fuel is returned to the main tank. The surge tank system however will not empty until the fuel has been consumed by the engine as any excess fuel is returned to the surge tank.

The typical carburettor setup only pumps fuel when the fuel bowl empties so the swirl pot will only empty as the fuel is consumed or gravity drains the pot.

I intend to remove the plate from the spare tyre area of my Brown Davis tank which has never been used. Install a surge tank and replace the spare tyre area plate with a flat plate which should leave remove to mount the pumps. I am not comfortable with the idea of having fuel system components inside the car. (boot/hatch)