A car's fuel system is the lifeblood of your combustion cycle. If a pump maxes out and is unable to deliver the fuel the injectors need, a lean situation can lead to detonation. The stock, single fuel pump simply doesn't create the amount of volume we need for our ECS/Paxton supercharged, LS3-powered 350Z. We turned to Russell, Fuel Injector Clinic, and CJ Motorsports to build a stout but reliable fuel system for our Z33.
Several companies offer single pump upgrades that work with the Z33's stock fuel pump module but none of these single, in-tank pumps can supply the volume we need. Our fuel demand at wide open throttle necessitates a minimum pump flow rate of 520 liters per hour. Even twin 255-lph pumps aren't going to be enough.
A look at the parts:
- CJ Motorsports 255/450 twin-pump module
- Edelbrock PN 1729 1:1 rise rate fuel regulator
- Russell PN 64900 10-micron billet -8AN fuel filter
- Russell ProClassic II -6AN and -8AN hose
- Russell Full Flow hose ends, coupler, and adaptor fittings
- Innovate Motorsports ECB-1 with flex fuel sensor
- Fuel Injector Clinic IS303-1000H 1000cc injectors
The CJ Motorsports twin pump module is the heart of the system. Ours contains the 255/450 pump combination that will support around 850 rear-wheel horsepower on E85. The 255 pump will operate as the primary under normal operation and then the 450 will switch on via a Hobbs switch at 2 psi of boost. This method keeps the fuel cycling to a minimum and ensures optimal pump life.
The pump module retains the use of the factory fuel level sending unit and has three ports on the top hat - two feeds and a return. The return dumps back next to the fuel pump's pickup and also retains the use of the factory jet siphon system. We enlisted the help of Jeff Jordan of Jordan Innovations to help wire our car, including the twin-pump system.
Russell ProClassic II -6AN hose and fittings leave the hat and enter a Y-block under the car. Two -6AN lines merge to a -8AN male that is then connected via a female-to-female Russell coupler fitting. On the other side of the coupler is a Russell inline 10-micron fuel filter. Russell's low-profile, 12-inch billet filter housing is double o-ringed and contains an E85 compliant paper filter, which can support up to 1,800 horsepower worth of fuel flow.
The -8AN Full Flow straight fitting with ProClassic II line end the feed line feed at the back of FAST's billet fuel rails on the passenger side. These straight through rails feed a set of Fuel Injector Clinic 1000cc injectors.
"Typically there are two ways to increase the flow of an injector," explains Fuel Injector Clinic's Tim Jilg. "You can either increase the travel of the valve or you can change the opening the fuel can flow through. Both have to be handled very carefully with lots of post-modification testing.
When opening the fuel flow orifice, there are some reliable modifications that can be done when you have the equipment to test both the effect of your modifications as well as providing the new computer data to make the injector work correctly after the modification. So we advise any potential customer to ask about the method of modification and certainly demand full data of the modification when choosing this route."
The backside of the driver's side fuel rail begins the return back to the tank. Before doing so it enters an Edelbrock 1:1 ratio EFI fuel regulator. The silver and black finish of the regulator matches our Russell fittings and is made from air craft grade aluminum. A fluorosilicone diaphragm provides extended life and high temperature protection. Adjustable from 35-90 psi, the Edelbrock 1729 is also compatible with gasoline or ethanol.
Before returning to the tank the fuel line passes through an Innovate Motorsports flex fuel sensor. Late model Chevy PCMs can be wired for a flex fuel reference signal to enable the flex fuel tables. Additionally, the flex fuel sensor feeds an ECB-1 gauge. This nifty 4-in-1 gauge reports the ethanol content percentage, temperature of the fuel, boost pressure, and air/fuel ratio. We will cover the installation of this gauge in a later segment.