Fuel Pumps 2.0

4.2 V8 40v biturbo - 450 bhp
4.2 V8 40v biturbo - 480 bhp (plus)
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anditsoundslikebells
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Fuel Pumps 2.0

Post by anditsoundslikebells » Thu May 21, 2020 2:59 pm

Hi,
I've been researching the work that needs to happen to my 2002 RS6 when it goes in to have the gearbox rebuilt (I'll post about the TC & rebuild on here when that is all finalised).
From another thread about turbo rebuilds and with help from Classik&Ajc&IchBautAuto I've come to understand a little about the fuel pumps.
Ultimately I'd like to replace and uprate the pumps as they're 18 years old.

I understand that the Bosch044 is common but Walbro also makes a pump with the same (or better) flow rate but quieter.

I'm now thinking to get these two:
in-tank
https://walbrofuelpumps.com/walbro-450l ... otive.html

in-line
https://www.aemelectronics.com/products ... -fuel-pump

It seems that both of these will fit with relative ease into the original positions.

Can anyone help me to understand how to provide these pumps with their required Amps? (as you might have guessed, I know nothing about car electrics). Also, the RS6 has a variable voltage... would this impede the above pumps?

Cheers

Classik
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Re: Fuel Pumps 2.0

Post by Classik » Thu May 21, 2020 9:08 pm

Hi,
These are indeed the pumps I've bought as an upgrade from oem, but bear in mind the setup has still not been installed nor validated, and that in my case the upgrade is required because of my use of e85 (higher fuel consumption and viscosity), so reaching for stronger pumps may bz just throwing money down the drain in your case.
FWIW I can confirm a single Walbro F274 (in-line pump bypassed) can feed an 'optimized' rs6 c5 up to 670hp (not mine but tested on a dyno), but you'll get a fault on the dashboard due to the missing (in-line) pump.
I can't answer your question about the wattage properly, but I'd be surprised if those pumps would overload the car electrical system.
RS6 C5 Avant 2003 Daytona Grey
Milltek cat-back - 200 cells cats - Wagner IC - Multimap e85/98RON - MTM Wheels - Bilstein B16 - Hybrid Loba 650 turbos - Soon to come: upgraded fuel pumps

anditsoundslikebells
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Re: Fuel Pumps 2.0

Post by anditsoundslikebells » Fri May 22, 2020 11:49 am

Thanks again Classik. I do get your point about this being overkill but I figured I am going to replace the fuel pump anyway to be sure and why not prepare for a possible 650bhp in the future.
Although not 100% confirmed, the transmission rebuild I'm aiming for is good to 580bhp, so up 30% on the original. I guess a new pump, OEM or otherwise is a good idea for this.
I'm now also just curious about the increased wattage and how to deal with that.

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Weiß-sechs
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Re: Fuel Pumps 2.0

Post by Weiß-sechs » Fri May 22, 2020 12:52 pm

anditsoundslikebells wrote:
Fri May 22, 2020 11:49 am
Although not 100% confirmed, the transmission rebuild I'm aiming for is good to 580bhp, so up 30% on the original.
Is this info from SportMile or RSE?
I'd be more interested in the numbers on Nm tbh, torque is a bigger 'box killer than just having bhp figures.
"Subscribed". Keep us updated.

jolio1994
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Re: Fuel Pumps 2.0

Post by jolio1994 » Fri May 22, 2020 1:09 pm

Not sure if you need to run dual pumps or not, but I installed a Hellcat 525lph pump and it's been great. Rated up to 850hp and it's super quite (Even though my turbo and exhaust is right in my face)

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IchBautAuto
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Re: Fuel Pumps 2.0

Post by IchBautAuto » Sat May 23, 2020 1:07 am

Classik wrote:
Thu May 21, 2020 9:08 pm
..........................
I can't answer your question about the wattage properly, but I'd be surprised if those pumps would overload the car electrical system.
They won't overload the electrical system as such but as they draw a greater electrical load, the OE wiring specification and fuses may not be up to spec for the greater current draw of the pump.
C5 RS6, Milltek and Wagners: B5 RS4 450 + HP: A4 1.8 GP TQS original: 1963 UNIMOG 404:

anditsoundslikebells
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Re: Fuel Pumps 2.0

Post by anditsoundslikebells » Sat May 23, 2020 1:37 pm

Firstly, about the gearbox.... I'll write a thread about it when all is done and I have some facts.

I'd like to continue to run 2 pumps to avoid a warning and reliability.
The idea of a quieter pump is appealing, so Walbro over the Bosch 044.

I've spoken with my friend who has 700bhp bug-eye Japanese car he's been building himself and he has fitted the Bosch 044 in-line in the boot. To get around the OEM wiring issue he has used new wiring directly to the battery (as IchBautAuto mentioned) with fuses, then link the signal wire to the ECU. He thinks he used 16AWG wiring for this setup.

In terms of pumps there are also the Walbro 340 pumps which should handle the 580bhp. It has 3 different configurations & 255LPH:
F20000311 = GSS340 with a higher pressure relief. 22mm center inlet
F20000312 = GSS341 with a higher pressure relief. 11mm inlet, 180 degrees from the outlet
F20000313 = GSS342 with a higher pressure relief. 11mm inlet, in line with the outlet

https://walbrofuelpumps.com/walbro-gss-fuel-pumps

I've had a read of the self-study guide and found the reference to G6 but no sizing, LPH specs.

Working this one out seems tricky.

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