Need to re-do the fuel system, wondering if theres a billet hanger available that bolts to the OEM fuel tank.

Using a Walbro 450LPH in tank pump with Flextronics harness, and the stock fuel level sensor/float will not work as Im packing the tank with fuel tank foam. Prefer AN6 or 8 output and AN6 return.

I would also fit a cylindrical aftermarket fuel level sender, but not sure how I had to bolt on to the top of the tank.

Any ideas welcome. Even a retrofit in tank surge tank that can be fit. Or an aftermarket tank if I have to go that far, but much prefer the stock tank.

650hp mill and flex fuel setup.

 

When I put my 450 lph pump in I fabbed my own hanger. I didn't use foam though so my job was a lot easier. But I used a -8AN bulkhead fitting for the feed and the old factory feed as a return on the top of the sending unit. I used a float and fuel level sensor from a newer Chevy truck so it was E85 compatible. The ohms where different so I used a cheap converter box so the gauge could read the signal. So far everything works like a charm.

I posted a pick of what I made on a LS build thread a few years ago I'll see if I can find it. It doesn't look pretty. But the best part about the fuel sending unit is you can't see it.

 

Found them.



so in the second pic you can see the -8AN bulkhead fitting connecting to the Walbro hose. Also I welded a tube on the old feed line that I converted to a return so it dumps the returned fuel directly on to the sock. To use that fuel level sender I had to bend the wire a lot to get it to work. That part was probably the most time consuming. But using the converter box allows me to "tune" the fuel level gauge. So I filled the tank until fuel just came up to the sock and set that point as the lowest point. Then filled the tank at the gas station until the gas pump shut off. This I set as the highest point. Now my fuel gauge works amazingly well.

 

Good stuff, thank you. I’ll probably end up with some sort of a contraption like that. Best thing to do with the fuel sensor may be to leave it out.

 

I debated going with an optical fuel level sensor instead of the float style. But the price of those was a bit much. So I did it this way. I'm happy with it. But the optical version might be something to look at if you don't feel like messing with the float arm.

 

Got some work done on the fuel system... and mostly done with the fuel pump, just need to finish the wiring, and figure out the fuel quantity challenge. Open to suggestions. Tank is filled with blocks of fuel tank foam with a void in the center so the regular float is not really an option.

 

Finished with the OEM style hangar, didn’t make anything special so no room for fuel level sensor with the foam blocks in the tank. Didn’t have the patience to modify the fuel tank for a probe to be honest, and OEM fuel tank and bladder are in great shape. 8AN feed and 6AN return is worked out.

6AN fittings and 3/8” Copper Nickel at the Hager as shown, expanded to 8AN at the bulkhead fitting. 1/2” Copper Nickel hardline 8AN connections installed for the fuel feed from there with filter and ethanol sensor on the firewall.

Now I need to figure out the PWM/SSR/Holley-HP control, looks like my super fast SSR is -P control type, so I have an isolated negative pump circuit.

 

What made you go with an SSR for the fuel pump?

I think most automotive SSR's are -P (NPN). I know the Holley SSR I use for the progressive nitrous is.

 

Its a return style system.

One reason is that the Holley can handle the Pulse Width Management (up to two +P channels and two -P channels on mine, otherwise there are some nice independent controllers also) so then the PWM for Fuel Pump needs a proper Solid State Relay.

Without PWM for the pump, fuel heating and power consumption is higher. I think it needs a much faster swittching SSR for proper PWM than the Holley NOS SSR (for fuel pump requirements) but at the Holley training class they said it works OK, 500-1000Hz seems to be what we can work with using an SSR for a higher freq. This one handles 2KHz which is higher than the Holley ECU is capable of, and only $28. My issue with -P is that the negative/ground wiring needs to be isolated, and it needs to have the wire gauge requirement for the length and amps. Pump consumes 20A at full flow and pressure. I think I have it handled, the circuit grounding all the pump parts and ground connections are separated. The Racetronix wiring loom grounds out the negative bypassing -P so thats changed. Not sure if I should mount the SSR close to the pump or on the aluminum structure behind the console/dash, I’m leaning towards the rear speaker box area.

Not sure if I will use the original fuel pump relay as shown using the Holley FP wire (green loose wire) or if I should connect the green to the SSR, it would be weird to run direct battery power on a 12ga wire all the way to the pump, always connected.

 

That looks really well done certainly better than the custom ones I made. I experimented with several designs and different pick up types / shapes like hydra mat. All the effort it's better to do a fuel cell that stock tank is so long.

 

Thanks. But I think there would be a a little bit of demand for an aftermarket hanger to the OEM bolt pattern, and -8 feed -6 return with Capacitive 0-90 ohm fuel level sensor, maybe a narrower filler neck so there’s room. Perhaps $600-800 range? ZR1 or anyone with a Supercharger Turbo or hot NA. I have a really nice billet one for the Ducati 1098R, I’m thinking same idea.

yes a fuel cell would solve many of the issues to be addressed by a nice aftermarket hanger.

screwed around with it long enough, its installed and just need to finish wiring it and setting up the Holley for the advanced FP control. Few other details if anyone cares:

 

I agree there is a market for that tho no idea on price. It looks like your fp is where the blower used to be? A build thread or more pictures here would be interesting. Oh and have you tried a baffle around the whole hanger? It didn't seem to help on mine but I had the wide open long tank without foam.

 

couple of years ago, installed a ~350 RWHP engine and upgraded some of the components to the Racetronix kit (255LPH pump, filter, hose, and a new eBay hanger, that’s about it. I believe it had an aftermarket pump and no pulsator originally. Installed foam blocks from Speedway which stacked on top of each other, and stuffed them into the sides, so there was a gap in the center for the hanger. Some of the blocks shifted, so the float no longer worked, but the foam worked great to reduce slosh related weight movements associated with slaloms and 1/4 to 3/4 tank etc. Car handled better with a full tank and passenger, so never encountered any G force related starvation.

now I have a 500+ RWHP engine with a little more compression, so wanted to be able to run E30-E50 fuel and needed more pump capacity, larger feed line, heavier gauge wiring etc. the fuel pump is installed in the original location, got the 6AN Radium adapter, and made some 6AN cu-ni hardline to 8AN 90 degree bulkhead fitting (cut out old feed line).

Removed all of the OEM fuel lines… was going to use the old return line, up to the connection near the old fuel filter location… but noticed that in the original installation, it was crimped/damaged by the clamping, so I figured it’s best to install a 6AN PTFE return line.



The blower motor and heater core were removed, and an aluminum bulkhead installed on the firewall, with some insulation on top. Mounted the fuel filter here with 8AN inlet at the bottom, and Ethanol sensor on top.

will have an 8AN 90 degree hose fitting and PTFE hose to the fuel rail. Radium fuel pressure regulator and damper on the other side of the fuel rail (mounted to a plate which is mounted to the cylinder head)

From there, the 6AN return yet to be installed.

I don’t have any more pictures here on my phone, outside of the ones already in this thread. I should update when engine is installed.