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Doing some flex fuel tuning on my 1990 BNR32 and looking for some advice.
Fuel wise, I put in a walboro 450 lph, 1000cc ID injectors, and nismo FRP. Kept the stock fuel rail.
My tuner is still working some kinks out of the tune (AEMv2 with AEM's flex fuel sensors). We got 435 whp on 92 octane and 494 whp on e70, no more due to maxed fuel delivery. I'm fine with those numbers on a stock bottom end, but I didn't think I would be limited by fuel delivery with my set up.
I'm also going to replace all the non-hard fuel lines to withstand e85. I'd like to order some and do that over the winter.
Anyone done that before? Any idea about how much fuel line length I'll need?
Also wondering where the bottle neck might be in terms of fuel deliver, I'm not going to up the power more, just curious.
Thanks in advance!
 

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I'll make it easy for me, did this last winter and tried my best to understand what and why.

Look at what I wrote -> http://www.gtr.co.uk/forum/4767618-post4.html

And then look at this picture of the walboro flow/pressure chart here:
walbro-400lph-charts_3.jpeg

15 psi boost + 45 psi base fuel pressure = 60 psi, that gives you a best case flow of 346 lph :)
If you got a bit low voltage thats down to 288 lph..
 

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Thanks man, that's some good info there.
I do have a fuel pressure sensor that is wired into my ECU, I don't think there was a significant drop pressure/amps with boost and rpms.
Did you swap out your "rubber" fuel lines as well?
 

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Thanks man, that's some good info there.
I do have a fuel pressure sensor that is wired into my ECU, I don't think there was a significant drop pressure/amps with boost and rpms.
Did you swap out your "rubber" fuel lines as well?
All new, went overkill so I wouldnt have to do it ever again :)
Pump flows 530 lph @ 3 bar/45 psi and is scary big (and noisy), also made a 2 litre swirlpot that fits inside the stock tank to avoid starvation.
I used braided teflon fuel lines and anodized aluminum hard pipe to avoid any issues with ethanol. From the tank to the front of the rear subframe took about 1 meter of line (each) and about 0,5 meter in the engine bay.

Having measured fuel pressure is great to know that it isn't the issue :clap:
 

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How is the fuel going to enter that swirl pot?

It's also not a good idea to have open terminals with ethanol, if you have fitted the power feed the same in the tank, then you should think about re doing the wiring.
 

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How is the fuel going to enter that swirl pot?

It's also not a good idea to have open terminals with ethanol, if you have fitted the power feed the same in the tank, then you should think about re doing the wiring.
On the inside picture you see the lift pump, it is mounted through the bottom of the swirlpot :thumbsup:
No open terminals with ethanol? Didnt know that, please explain briefly why, I just assumed that it was ok since the original connectors are open.
 

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On the inside picture you see the lift pump, it is mounted through the bottom of the swirlpot :thumbsup:
No open terminals with ethanol? Didnt know that, please explain briefly why, I just assumed that it was ok since the original connectors are open.

So the pump you see in picture is just to fill swirl pot? Does your main feed pump fit in the swirl pot or have you got that mounted externally?

Ethanol is conductive so it's not reccomended to run open terminals, that's why the walbro 450 has a fully sealed plug and terminals.

On my Evo I fitted twin 450 and I just drilled a hole in top and used a groumet for the power leads to run through to save any open terminals
 

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So the pump you see in picture is just to fill swirl pot? Does your main feed pump fit in the swirl pot or have you got that mounted externally?

Ethanol is conductive so it's not reccomended to run open terminals, that's why the walbro 450 has a fully sealed plug and terminals.

On my Evo I fitted twin 450 and I just drilled a hole in top and used a groumet for the power leads to run through to save any open terminals
Ah ok! Should probably fix it before I install the flex fuel sensor :thumbsup:
The main pump is mounted below the rear seat and has to draw fuel from the pot. Its below fuel level so once the air is out, it works. Not completely satisfied with the solution, but its good enough so it might take time to do something about it :eek:

Angrychicken: thanks! Havent seen the solution before, and its not without compromises..:cool:
 
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