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Discussion Starter #1
I'm currently looking at fuel system set-ups, I'm planning on doing 2 different engine builds on my supra. One will be low power and hopefully similar to a GTE single turbo, the other (providing that all goes fine) I hope will be around a 700whp build with forged internals. At the moment I want to change all the diff bushes, do an underseal and while I'm at it I may as well do brake lines and get my fuel system set-up.

I'll be running on petrol rather than e85 but I think I'll need a 8AN for fuel delivery and a 6AN return. I also plan on having a twin pump surge tank set-up with only 1 pump running while I'm on the the low power set-up. I'll run a standard fuel rail on the low power set-up but run a dual feed rail with a Y piece coming off the 8AN line to feed from both sides. Can anyone see any potential problems with this? Would it be best just to keep the rail single feed rather than splitting?

I've seen the sticky on here in the DIY section where 2 6AN lines are run to the rail from 2 in tank pumps and a single line for return, I question what's the benefit of running 2 smaller lines rather than 1 big one which then splits with a Y piece?

I'm not set on the surge tank or location yet, what would you guys recommend?

The car will just be for fun, I'm not really worried about fuel pump noise however if selling the car on the next owner might, be.

Also I'd like to see photo's of your set-ups if you're happy to share.

Thank you.
 

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I would just run a walbro 450 pump, a nice single set of high impedance injectors that will get you to 700whp reliably, and upgrade your feed line to atleast -8an and upgrade your rail. Feed from one side and return from the other. Simple and done.

What do you mean by two engine builds?
 

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Mind if I do a J?
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A single Walbro 525 "Hellcat" pump will do over 700whp on ethanol and like 900whp+ on race gas. Same size as the 450 and right around $180 with install kit. I'd just do that with a single -8AN feeding the rail, plug the middle, and -6AN return out the front. Super simple. No need to overthink it with the surge tank stuff.
 

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A single Walbro 525 "Hellcat" pump will do over 700whp on ethanol and like 900whp+ on race gas. Same size as the 450 and right around $180 with install kit. I'd just do that with a single -8AN feeding the rail, plug the middle, and -6AN return out the front. Super simple. No need to overthink it with the surge tank stuff.
700 wheel on E? What? Link to any flow charts?
 

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Mind if I do a J?
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700 wheel on E? What? Link to any flow charts?
I don't have any flow charts, I'm sure you can just google it, but yeah we did 717whp on Aaron's MKIV (Driftmotion, white, 1JZ block 2JZ head with GT4276R) on a single 525 pump and E85.
 

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Discussion Starter #6
Thanks for coming back to me with your advise, I'm certainly leaning towards the idea of a single pump now, funnily enough I watched an interesting video on YouTube last night on the Mazzei Formula RX7 fuel system set-up. He talked about the issues with surge tanks and that people over complicate the set-ups (exactly as you're telling me :LOL:). A lot was to do with the fuel heating up and also the current draw when running multiple pumps. His solution was basically a hole cut into the bottom of the fuel tank and a surge tank welded on, he then used a mechanical pump and a fuel cooler on the return.

What do you mean by two engine builds?
I've got 3 NA 2jz's, 2 vvti and 1 non vvti (from supra)

The non VVTI engine is in terrible shape, it has almost every leak possible. I'm going to strip it down and replace any bad parts with good ones from a VVTI engine, I'll then run this on a similar power a single GTE. I'm doing this for the sake of learning and cost, it will be the first engine I've ever rebuilt and doing this will be cost effective. If this all goes well I'll do a proper build (built engine, standalone ecu etc) but getting bits over the period of a year or so.

A single Walbro 525 "Hellcat" pump will do over 700whp on ethanol and like 900whp+ on race gas. Same size as the 450 and right around $180 with install kit. I'd just do that with a single -8AN feeding the rail, plug the middle, and -6AN return out the front. Super simple. No need to overthink it with the surge tank stuff.
I'll admit I haven't even really looked at the fuel tank from beneath, I had a look for diagrams but I couldn't find any decent ones. Is the fuel pick-up in a decent position then?
 

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Here is a good article showing you what the Walbro pumps can do: https://www.realstreetperformance.com/blog/fuel-pump-test-2018-real-street-performance/ - there are several charts that show you what you should be able to flow. Ensure that the pumps are wired well, I've first hand experienced some hack job work on wiring leading to issues. It's somewhat common. The hellcat pump draws some juice so make sure you've cut no corners ensuring a stable supply feeding it.

With a single Hellcat, assuming 43lbs of base pressure and pressure rising 1:1 with boost, it can keep up with most folks' setup running E85 all day.

A single feed fuel rail setup is suitable. My setup is in the signature.
 

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Discussion Starter #8
Thanks for that, I'm set on a single pump now, the only thing I want to be sure about now is whether the factory pick-up will be okay when doing hard pulls.

On this thread the diagram shows 'with jet pump' and without, I've tried searching for this 'jet pump' but can't find anything on it other than Whiffbitz selling an expensive kit with a description saying that the factory supra pick-up isn't very deep.

Most people say they just keep over a quarter of a tank of fuel and they're fine but I'm interested on this 'Jet pump' and whether all supra's have them from factory or not.
 

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Again I think you're over-complicating this whole thing. The way I would do it is use a single Walbro 525 "Hellcat" pump and use a -8 (you could even do -6 feed for 700whp) bulkhead fitting on top of the hanger for your feed. When you install the fuel pump make sure it sits down in the hanger to where the filter sock is level with where the stock filter sock would be. Done deal.
 

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My only one issue is that I cannot put a hardline on the walbro pump. The dump fuel hoses like to blow in the tank.
Use the high pressure E85 compatible hose from Gates. I don't have a part number handy. I run that from the pump with a hose clamp to the bulkhead with a push lock fitting with hose clamp. If it's a dual pump setup I'll use a Y fitting in tank with 45 degree push locks at the bottom and a straight at the top. Been making 1000whp+ for a couple years on systems like this. I'm sure there's a more proper way to do it, kinda like Darian (SDstreetracer) I know uses hardline and it's super awesome, but this works too.
 

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Use the high pressure E85 compatible hose from Gates. I don't have a part number handy. I run that from the pump with a hose clamp to the bulkhead with a push lock fitting with hose clamp. If it's a dual pump setup I'll use a Y fitting in tank with 45 degree push locks at the bottom and a straight at the top. Been making 1000whp+ for a couple years on systems like this. I'm sure there's a more proper way to do it, kinda like Darian (SDstreetracer) I know uses hardline and it's super awesome, but this works too.
This is how I did it on my MK3 with a Bosch 044 in the tank. It was all hardline.

How did they do it on the Walbro? The Bosch, I used a AN fitting on it and has the line made with a female end and installed it that way.
 
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