b'EFI Fuel Plumbing Tech Tip:Picking the right fuel cell for your needs can be tricky. We want to simplify things a bit. First is volume & second is shape. The three tanks on the next page have similar volumes, but the slant bottom version allows you to get the fuel load closer to the rear axle, reducing the polar moment. Where the traditional rectangle places the fuel load lower a bit, but farther rearward, increasing the polar moment. In layman terms, the slant bottom cell will make the rear of the car break loose with a lower pendulum effect (less violent), where the rectangle, flat bottom tank will break loose with higher pendulum effect (more violent). Pick the slant bottom if you can make it work. It works well with most bodied car rear quarter panel shapes & makes adding effective rear diffusers easier. You never want to carry more fuel load than you need on track. For this reason, racers dont fill up with fuel. They calculate what fuel they need & add a small cushion. The less fuel load you have, the lower the pendulum effect youll experience when the car gets loose. This is not only easier to driveeasier to save the carbut quicker too. Of course, not having a large enough cell for the needed fuel load is a problem with no easy solution. If in doubt, pick a cell with a gallon or two more volume than you think you need. Foam?Yes please. Safety foam baffling minimizes fuel slosh & explosion potential. No brand of foam (regardless of what their ads say) survives alcohol (methanol nor ethanol). Running pump gas with 10% ethanol is no biggie. But running E85 or 100% alcohol will eat the foam & shred into little pieces inside the fuel cell, fuel pump & into your fuel injectors or carb. Do you need a collector/surge tank?Yup!For road racing, track day cars and/or autocross, the side G-forces will starve your fuel pump & engine for fuel without a collector/surge tank. The common 6x6x4 tall collector with three check valves or trap doors works well. Our Track-Car Cells utilize three plastic trap doors to use every ounce of fuel. Our Race Car fuel cells use the much more expensive aluminum trap doors that pro race teams want. Your call. Radium is a company with a new style of surge tank that utilizes a fuel pump (not trap doors) to pump fuel into the collector, keeping it full, so your fuel pump & engine never starve for fuel. They work excellent. Cost a bit more in the single fuel pump layouts & are about the same cost for dual fuel pump layouts. Another benefit is the wiring is all on top, outside the cell. Your internal pump(s) will need to be low pressure (8-15psi) for carburetion & high pressure (45-60psi) for fuel injection. How much fuel volume you need is a function of how much power you run. We have had great success with the Aeromotive Stealth 340 pumps. Without going into all the variables & calculationswith a well designed -8 AN plumbed supply & return systemone Stealth 340 pump will feed 700HP naturally aspirated EFI engine without worries, even on pump gas with 10% ethanol. More than 700HP?Step up to dual pumps. If you plan to run E85, Ethanol or Methanol race fuels, call me & lets calculate your fuel needs. 676'