Fuel line size for E85, is -8AN feed line enough?

[04OWwhipple]

I'm breaking in my new engine and am starting to do almost full pulls. AFR stays pretty rock solid until about 6000 RPM and up. I datalogged fuel pressure and fuel pressure drops about 10PSI from 5800 to 6700 RPM. This is also on just pump gas right now, I haven't began tuning for E85 yet.

Setup is 9.2:1 compression 4.6 with stock cams and whipple 2.9. Currently making 17PSI ramping up to 19PSI by 5000RPM or so.

Fuel system is return style with dual pumps with -8AN feed line and -6AN return, Fore fuel rail and ID1300 injectors. What power level will -8AN feed support on E85?

 

[01yellercobra]

What pumps and regulator are you running? Are you running the stock hat?

 

[BlckBox04]

yes

 

[04OWwhipple]

What pumps and regulator are you running? Are you running the stock hat?

Dual 465's in aftermarket hat and Fore regulator with base PSI set to 58.

 

[SVT_Troy]

Have you double checked your routing making sure your lines aren’t kinked? I think you should be good with your current line but I do personally run 8 feed & return


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[04OWwhipple]

Have you double checked your routing making sure your lines aren’t kinked? I think you should be good with your current line but I do personally run 8 feed & return


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I have not double checked the routing but the fuel hat, pumps, lines, and regulator have been on the car for about 7 years. I recently rebuilt the motor over the past year and added the Fore fuel rails and ID1300s. Outside of that the fuel system hasn't really changed. I'm wondering if one or both of my pumps are starting to get weak. I was just thinking of upgrading to larger lines for future use as I plan to turn it up from here on E85 quite a bit.

 

[SVT_Troy]

I’m not smart on diagnosing data logs but have you asked you tuner? Dropping 10 psi in upper RPMs only sounds like a restriction. What fuel filter are you running and when’s the last time you’ve replaced it?


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[9397SVTs]

Why are you using such a high base pressure?

Which 465's do you have? NOTE: THE WALBRO F90000274 AND F90000267 FUEL PUMP FLOW RATES AND PHYSICAL DIMENSIONS ARE IDENTICAL. THE WALBRO F90000274 SIMPLY HAS A DIFFERENT INTERNAL RELIEF VALVE PERMITTING HIGHER FUEL PRESSURES

#267: 87 psi max
#274: 120 psi max

 

[SVT_Troy]

Why are you using such a high base pressure?

Which 465's do you have? NOTE: THE WALBRO F90000274 AND F90000267 FUEL PUMP FLOW RATES AND PHYSICAL DIMENSIONS ARE IDENTICAL. THE WALBRO F90000274 SIMPLY HAS A DIFFERENT INTERNAL RELIEF VALVE PERMITTING HIGHER FUEL PRESSURES

#267: 87 psi max
#274: 120 psi max

I know it’s a sensitive topic but plenty of folks run higher than OEM base fuel pressure without issues. It’s a tuners preference and I’m not knowledgeable enough to debate it.


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[04OWwhipple]

Why are you using such a high base pressure?

Which 465's do you have? NOTE: THE WALBRO F90000274 AND F90000267 FUEL PUMP FLOW RATES AND PHYSICAL DIMENSIONS ARE IDENTICAL. THE WALBRO F90000274 SIMPLY HAS A DIFFERENT INTERNAL RELIEF VALVE PERMITTING HIGHER FUEL PRESSURES

#267: 87 psi max
#274: 120 psi max

To be honest, I'm not sure which pump it is. The previous owner installed them. All I know is that they are 465's. I'm using a higher base pressure due to after talking to injector dynamics they stated the atomization would be better at higher pressures.

I know it’s a sensitive topic but plenty of folks run higher than OEM base fuel pressure without issues. It’s a tuners preference and I’m not knowledgeable enough to debate it.


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58 PSI is also pretty standard pressure among a lot of GM pressures. So far I haven't had much issue and at idle the Haltech seems to handle the large injector and high pressure just fine.

 

[9397SVTs]

Well....you're starting at about 20 psi over stock and adding an additional 19 psi (1:1 ratio). This puts you around 77 psi. Depending on the actual pump you have, it could be bleeding pressure.

 

[04OWwhipple]

Well....you're starting at about 20 psi over stock and adding an additional 19 psi (1:1 ratio). This puts you around 77 psi. Depending on the actual pump you have, it could be bleeding pressure.[/QUOTE

I see what you are saying but at that level I should still have 10 PSI to spare before the relief valve has any effect on anything. I suppose I could dropping the pressure to 43.5 and adjust the injector dead times and make a pull just to see what it does. The other reason I have it at 58 is due to the fact that I will be running 25-27# of boost on E85 and also have my nitrous fuel feed coming off of the end of my fuel rail

 

[9397SVTs]

The stated value for relief pressure is for a product that is mass produced. You're results may vary. Add to it the fact that they have some age and have been constantly driven at higher base pressures, they could be wearing out.

I would try lowering the base. This will also improve the flow volume up top. As pressure increases, volume decreases.

 

[Shadow Grey 03]

The stated value for relief pressure is for a product that is mass produced. You're results may vary. Add to it the fact that they have some age and have been constantly driven at higher base pressures, they could be wearing out.

I would try lowering the base. This will also improve the flow volume up top. As pressure increases, volume decreases.

Pay attention to what this guy is pointing out. 58 psi base pressure is damn high on these cars. It isnt an LS car that runs those pressures stock. For the pumps you have you can see enough volume to support upwards of 900 wheel on e85 with much lower pressures. Assuming that the pumps are in good working order and the voltage to the pumps is consistent.

 

[04OWwhipple]

The stated value for relief pressure is for a product that is mass produced. You're results may vary. Add to it the fact that they have some age and have been constantly driven at higher base pressures, they could be wearing out.

I would try lowering the base. This will also improve the flow volume up top. As pressure increases, volume decreases.

I don't disagree with you there. I was just trying to leave a bunch of room for error with nitrous sytem as I haven't ever run nitrous myself before, hence the higher fuel pressure. I might give it a shot and drop the pressure and see how she responds.

Pay attention to what this guy is pointing out. 58 psi base pressure is damn high on these cars. It isnt an LS car that runs those pressures stock. For the pumps you have you can see enough volume to support upwards of 900 wheel on e85 with much lower pressures. Assuming that the pumps are in good working order and the voltage to the pumps is consistent.

Yeah, I was a Ford tech for 6 years and know that 58PSI is a step up from what it is factory so I understand where you are coming from with that for sure. In my head though, with a completely aftermarket entire ungraded fuel system and standalone ECU one should in theory be fine running whatever pressure they would like to an extent as long as the ECU can handle it.

 

[Shadow Grey 03]

Check flow rates for different pressures on the pumps and see what that data looks like. The Halltech is a nice setup too.

 

[03' White Snake]

I'm running my setup at near 60 psi base too per the recommendation of my tuner. I'm running 22 psi on e85 without issues. I have small 80 lb injectors making 785 right now. I am at 95% injector duty cycle. With larger injectors , I'll drop it down a bit. I'm running 2 465 pumps with -10 feed and -8 return for reference.

 

[04OWwhipple]

Check flow rates for different pressures on the pumps and see what that data looks like. The Halltech is a nice setup too.

I need to do some more investigating for sure. I love the Haltech setup so far. It definitely bring the engine management to todays cars level and has some much room for expansion that we could never do with the stock computers in our cars.

And I will say, Haltech's customer support blows me away every time I have a question regarding anything. Hands down one of the best companies I have ever dealt with in my life when it comes to supporting the people who buy their products.

I'm running my setup at near 60 psi base too per the recommendation of my tuner. I'm running 22 psi on e85 without issues. I have small 80 lb injectors making 785 right now. I am at 95% injector duty cycle. With larger injectors , I'll drop it down a bit. I'm running 2 465 pumps with -10 feed and -8 return for reference.

Nice! Those are solid numbers! I was making 715-740 depending on the dyno on 21PSI on my original engine until I found cracks in every cylinder on bank 2. Like I mentioned before, Injector Dynamics recommended the base pressure and a good buddy of mine who used to be co-owner of a ford performance shop said 58 is fine for base. I know there are plenty of people out there running it at that base pressure as well.

 

[GodStang]

I prefer -10an feed and return.

 

[Comp04svt]

The one thing that shouldn't be over looked here is that you need to log what your battery voltage is doing in the upper RPM range as well. If you have voltage dropping off due to a weak alternator or something along those lines, then I would think you would have the same symptoms you are having currently.