Dual walbro 450 fuel pumps? How??

[Clash0901]

Aside from the $1000 Radium engineering option...

How are you guys installing dual 450s? Or dual anything for that matter.

I am curious to see some pictures and it would also be helpful if somebody had a write up on adding a fuel return line to the BRZ tank. My plan was a -AN fitting on top of the fuel pump hanger which is probably the best way to do it but i'm open to suggestions.

Also, do the upgraded fuel pumps need upgraded power? Like being hard wired with a thicker gauge lead?

Thanks,

[spitfire481]

best way is to feed a surge tank with the stock fuel pump still installed. keeps the siphon working

[Hags86]

What fuel/engine combo are you running? Do you need dual pumps?

I have a single Walbro in a Radium surge tank with an uprated Deatchwerks in-tank pump. It maintains pressure on e85, turbo at 240 wheel Kw.

The Radium tank with built-in pressure regulator is a nice piece of kit. But I'd never buy another Radium product as they are complete c*nts to deal with.

[Dipstik-sportech]

Im running a single walbro 485 in an fbm hanger setup with a return style conversion. No issues with fuel at all on e85

[twag4]

Originally Posted by Dipstik-sportech

Im running a single walbro 485 in an fbm hanger setup with a return style conversion. No issues with fuel at all on e85

Got any pics of that assembled? I have one I’m about to hook up, and would love to see one put together before hand

[Dipstik-sportech]

Originally Posted by twag4

Got any pics of that assembled? I have one I’m about to hook up, and would love to see one put together before hand

Unfortunately it's in the car lol

[Hags86]

Sorry, don't have photo's but can talk you through how I did it.

Components

- Radium surge tank with built-in regulator
- Walbro 485 (part no F90000267 - e85 compatible) for surge tank pump
- DeatschWerks DW300C - to replace OEM fuel pump
- Braided hose with AN fittings (for surge tank connections) and quick connects for OEM fuel line connections.
- Fuel Pump Controller - I grabbed one from a wrecked 2015 WRX as it is the same part number as the FRS/BRZ 86
- Relay, fuse
- heavy gauge wiring
- light gauge wiring
- rubber grommets, cable ties etc


Plumbing

I used a headless (non-return) design same as the OEM. This means you don't need to run a return line back from the fuel rails to the tank. I used the Radium surge tank with built in pressure regulator mounted in the boot (trunk) on the left hand side behind the wheel well.

I'll try and get some photo's and update this post with how I routed the lines but one goes from the in-tank pump to the surge tank and the surge overflow goes to a bulkead AN fitting I put on the top of the fuel hanger. Drill a hole right in the middle of it.

The output of the pressure line from the surge tank (inbuilt Walbro) joins where I disconnected the output from the OEM tank at the hanger. The OEM line has a T junction about 50cm from the tank where it runs two lines to the front of the car - one for the direct injectors and one for the port injectors. Ideally you would use the larger diameter line from the surge tank and split into both these lines but it was just too hard to plumb. I kept this short OEM line and the T junction at it works fine.

Electrics

You need to decide if you are going to run the fuel pumps at 100% duty cycle (e.g. attached to 12V) or a Fuel Pump Controller (as is on the stock pump). The FPC takes an 80Hz pulse-width signal from the ECU and runs the pump slow at low engine RPM and fast at high RPM. This has two advantages as 1) the fuel pump is quiet when you are idling and 2) doesn't unnecessarily heat the fuel by continually pressurising it and then discharging it all via the pressure regulator. I put in a second FPC.

The OEM wiring is enough to run one high volume pump. I kept the OEM wiring and fuel pump controller for the in-tank pump. The DeatschWerks DW300C was a drop in replacement with some mods to replace the fuel sock etc.

The surge tank pump needs a bunch of wiring-

- I ran a heavy gauge wire directly from the battery to a relay I installed next to the surge tank. This then goes to the FPC Pin 1. Don't forget to put in a fuse as close to the battery as practicable. A 20A cable and fuse is sufficient but I ran a 60A cable and fuse to a new relay box in the boot. This then runs my differential cooler pump/fan also.

- This relay is energised with the ignition signal. I ran this from my ECU but you could piggy back off the OEM FPC.

- You need a pulse width modulated signal to drive the FPC. You could piggy back this off the ECU or the OEM FPC. I have an aftermarket ECU so am generating my own PWM signal so can run each pump at a different duty cycle.

The FPC controller wiring is:
- Pin 1- high current 12V (switched via a relay with ignition on and fused)
- Pin 2 - PWM signal
- Pin 3 - Enable signal
- Pin 4 - High current ground
- Pin 5 - -ve to fuel pump
- Pin 6 - +ve to fuel pump

I added a fuel pressure sensor on the output of the surge tank at the same time which has proved very helpful to both setting the fuel pressure regulator in the tank to 390kPa and for diagnosis of problems.

I'll take the back seat out and get some photo's of the plumbing if you really need it.

[Clash0901]

I appreciate everyone's input but it seems that nobody has done what i'm asking. Dual fuel pumps in the stock hangar. I can make it work but I just figured i'd see if any other people already went through the effort and I could save some time by picking brains.

[Hags86]

I'm interested in the rest of your build. What is in the engine bay that needs dual pumps?

[Clash0901]

Originally Posted by Hags86

I'm interested in the rest of your build. What is in the engine bay that needs dual pumps?

2jz gte VVTI. Build thread coming soon, at the moment just accumulating all the parts so not much to show yet.

[Hags86]

OK, makes sense.

There are a few options...

- the fuel hanger is in the left side of the tank and the right side a level sender only. You could put a hanger in the right side too. You'll find if you put the pumps in one side (or even just an uprated pump in one side) it will not siphon evenly. A pump in each side would fix this.

- there are two fuel lines heading from the tank to the engine bay. One is used for the direct injectors the other for port injectors. You could use one each for two pumps (if you want to retain a returnless system).

- surge tank big enough to fit two pumps.

In any of these you'll need both another set of power lines and, depending on whether the 2J ecu can control a fuel pump controller or not, a second FPC. Might just be easier to get rid of both FPC's and run a 100% duty cycle if you have a decent fuel pressure regulator.

[Clash0901]

Originally Posted by Hags86

OK, makes sense.

There are a few options...

- the fuel hanger is in the left side of the tank and the right side a level sender only. You could put a hanger in the right side too. You'll find if you put the pumps in one side (or even just an uprated pump in one side) it will not siphon evenly. A pump in each side would fix this.

- there are two fuel lines heading from the tank to the engine bay. One is used for the direct injectors the other for port injectors. You could use one each for two pumps (if you want to retain a returnless system).

- surge tank big enough to fit two pumps.

In any of these you'll need both another set of power lines and, depending on whether the 2J ecu can control a fuel pump controller or not, a second FPC. Might just be easier to get rid of both FPC's and run a 100% duty cycle if you have a decent fuel pressure regulator.

The MoTec ecu should have no issue running two pumps. I'm thinking of having one kick on after say, 10lbs of boost or something. Also, the surge tank is out of the question, I want to do this without one. The right side has an access door similar to the left side? If not I can make one myself but just curious if you know what it looks like. I'm sure it's easier said than done to utilize that as the second pump housing.

Ideally i'd run 2 pumps on one side and use one of the lines as a return for fuel.

[Hags86]

It's actually even easier than that on the Motec. The latest version of the FT86 package has control for:
- OEM pump via pulse-width modulation of via fuel pump controller (which I am using for the in-tank pump, and/or
- another PWM auxiliary output (which I am using for the surge-tank pump)
- a Pump 1 which with a basic switch control
- Pump 2 and Pump 3 which come on above a preset Litres/min requirement as defined by your fuel map.

See attachment for details.

I don't think there is enough room to get two pumps in the one hanger unless you get really creative.

[Hags86]

Yes, both sides have the same screw-on access cover. I've not removed the right-side one but according to the diagrams I've seen holds just a fuel float. The one on the left has the pump hanger/fuel float built into the same unit. I'd be willing to bet you could get another one of these and install it on the right side.