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Twin Bosch or Walbro In tank?

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Old 12-16-15, 07:36 AM
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Twin Bosch or Walbro In tank?

I am looking to run a twin in tank setup on my FD3 debating between a bosch 044 but a (310lhp version) and the walbro 440lph ones. I read somewhere that twin bosch is a complete pain to fit? Is this true? I will have much more fuel than I need either way. Cost wise bosch might be a touch cheaper.. but with the extra fitting needed for it maybe not much in it?
I will probably make up my own mount using the standard cover and bits.
next question is best way to plumb it but I will see what comes back from this.

Any advice please chaps?

Cheers
Lee
Old 12-16-15, 08:05 AM
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single Walbro 450, re-wire to direct batt power with a relay if you want and call it a day.
Old 12-16-15, 09:05 AM
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Have you considered a supra pump. Its a perfect fit replacement for oem. Dont know what your power goals are??
Old 12-16-15, 09:47 AM
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Bosch 044 are pretty bad *** pumps. Maybe one of those is really all you need? They are a pain to get the dual setup into the stock tank like you said, very tight fit.
Old 12-16-15, 10:29 AM
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I also say a single Walbro 450. I've moved away from dual pumps because it is just another failure point. If one pump dies, you will lean out and the motor can blow. If a single pump setup dies, the car will likely just shut off.

Upgrading your fuel pump wiring is essential with any aftermarket pump. The stock wiring is way undersized. Its approximately 10 gauge at the connector, then the Mazda geniuses decided to drop down to something like 14 or 16 gauge in the tank. The wiring overheats and melts the connector. I put a jumper in the fuel pump speed relay up front to bypass the fuel pump resistor. Then I depin the stock connector and insert larger pins with 10 gauge wiring. Each car is different and if I still see voltage drop at the pump, I wire in a relay.
Old 12-16-15, 11:56 AM
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I have been researching the past few days on aftermarket pump setups and have decided to go with the Walbro/TI Automotive 400 or 450. Way more affordable than a Bosch and can handle up to 500hp applications easily.
Old 12-16-15, 01:00 PM
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Just make sure to get it from a reputable vendor. Lots of fake ones out there.
Old 12-16-15, 01:04 PM
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another +1 for the walbro 400lph pump
im running one of those. very good so far..very quiet.
Old 12-16-15, 02:26 PM
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Just to give a bit more reasoning behind my twin pump. I am running a 20b conversion. Power goal will be around 600bhp at the wheels. Nothing crazy. But good to have scope for a little more. 650max. I think that is a bit marginal on the single Walbro 440? That would be my preferred option if it could work. I also hear the point about failures of one pump causing leaning out which does concern me and is something I have been pondering. Just not sure if I have a single pump option?

Cheers
Lee
Old 12-16-15, 04:44 PM
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Wouldn't a fuel pressure gauge help that problem ?
Old 12-16-15, 08:38 PM
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By the time you notice a pressure loss it will be too late. If you have a decent ecu you could program it to shut down the engine or reduce boost if fuel pressure drops beyond a certain threshold.
Old 12-17-15, 07:01 AM
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Not one for dash clutter and agree you probably wouldn't notice in time! Will look into options on Ecu. I have an older microtech unit.
Old 12-17-15, 07:32 AM
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Reading around some more there is a E85 version of the Walbro I was looking at called the GST450K. this is rated at 455lph and supposed to be good to over 700bhp. up to around 800bhp apparently.

Sounds like it could be the ticket on it's own which would make life easier!? And possibly consider running a large fuel line form the tank to the engine bay to help a bit more? Not sure what kind of a mission that is?!

Any thoughts or any other options?

Cheers
Lee
Old 12-17-15, 08:55 AM
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IRPerformance, what size are those pins to use in the stock connector and where can I get some? I just rewired mine and it isnt really up to my standards with the wires spliced etc. I'd like to redo it asap.
Old 12-17-15, 03:25 PM
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the pins on the wiring pig tale that come with the walbro fit into the stock connector (but the "key" on the walbro connector is the wrong way around so does not plug into the stock connector)

So I removed the pins / wires from the connector that came with the walbro, and they clip straight into the stock connector plug. Pins are the same.
if that's what your asking?
Old 12-17-15, 09:14 PM
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Originally Posted by silverTRD
IRPerformance, what size are those pins to use in the stock connector and where can I get some? I just rewired mine and it isnt really up to my standards with the wires spliced etc. I'd like to redo it asap.
I got them from Ballenger Motorsports. Hit me up tomorrow I have the info at the shop.
Old 12-17-15, 09:16 PM
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Originally Posted by Leeroy_25
Reading around some more there is a E85 version of the Walbro I was looking at called the GST450K. this is rated at 455lph and supposed to be good to over 700bhp. up to around 800bhp apparently.

Sounds like it could be the ticket on it's own which would make life easier!? And possibly consider running a large fuel line form the tank to the engine bay to help a bit more? Not sure what kind of a mission that is?!

Any thoughts or any other options?

Cheers
Lee
Just get the F90000267. That is the one I use on most of my higher hp builds. It fits in the tank relatively easily and is E85 rated.
http://walbrofuelpumps.com/walbro-f9...-fuel-pump-e85 the stock hard lines under the car don't start to become a restriction until after 500 whp. After that you want to run at least a -8 feed.
Old 12-18-15, 02:09 AM
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Cheers guys.. Yeah that is the pump I am talking about! Cool. I will go with that.
So I might want to consider a new line as well then as I hope to be around that figure. Would you retain the factory outlet on the oem tank cover or replace that with a fitting too? As I recall the pump outlet is the same size as the oem piping anyway?
Thanks for all the replies guys.

Lee
Old 12-18-15, 10:55 PM
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What are your power goals?
Old 12-19-15, 07:40 AM
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Hopefully just over 600bhp flywheel.. Not going to wild for a 20b! But would like some safety margin. Order the F90000267 pump and fitting kit now! Just debating on running a bigger line or not. Sounds like I should be okay on the stock hardline? Might stick with that for now and if I run in to trouble put a separate line in? Hhmm is the dash 8 a straight fit into the stock hardline OD? Not sure on my bore size for an fittings. If so maybe I should just get a line a do it now. Is it essential to run a larger line back as well? Under WOT surely less fuel is going back to the tank anyway?
Old 12-19-15, 01:11 PM
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I remember someone in here not long ago who installed 2 in-tank pump and upgraded the feed line to -8 Nd had some overheating problem with the stock return , change few things but problem persisted until that return line was changed to -6
Old 12-25-15, 01:20 PM
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Loving the walbro 400l/h pump, quieter the the 255-pump
Old 12-25-15, 01:57 PM
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Originally Posted by 7krayziboi
I remember someone in here not long ago who installed 2 in-tank pump and upgraded the feed line to -8 Nd had some overheating problem with the stock return , change few things but problem persisted until that return line was changed to -6
With my twin pump setup I had -8 feed, -8 return. Worked flawless I put around 2,000 race miles on E85. I was only making 501whp on a mustang dyno but she had a lot more into it!

Sammy
Old 12-25-15, 02:49 PM
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Cheers good to know. My new Walbro arrived the other day. Just in time for Christmas! Hoping I can find time to fit it up in the next couple of weeks!
Old 01-11-16, 04:10 PM
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remember, twin pumps double your potential for catastrophic failure! a single inherently safer.


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