Picture of my dual walbro setup
03-05-2006, 08:35 PM
#61
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Join Date: Aug 2001
Location: wilmington, NC USA
Posts: 252
Re: Picture of my dual walbro setup
Originally Posted by 97WS6Pilot
There are guys on this message board that are making close to 1000HP with stock lines, filter, regulater and a dual walbro. If you go with a bulkhead fitting out the top of tank then you must replace all the stock lines, get a new regulater, modify your fuel rails, and get a new fuel filter. If you don't do all these things the bigger fitting out the top of the tank is just for show. I think it looks really nice and I may go that route later. I didn't want to replace and modify my fuel rails and regulator.
If you get a chance look at the inside diameter of the outlet of a walbro 255 pump. It is tiny. It is approx. 1/8" ID. It also has a check valve that further restricts flow. Yet this small opening is capable of flowing 255lph. The inside diameter of the flex hose is 5/16." Inside diameter of the steel lines is 1/4" in some places. Believe it or not the plastic stock fuel lines are the least restrictive part of the system.. With the pressures that these pumps operate at they don't need -10 lines to move enough fuel. -10 lines in my opinion are for carburetors that operate at a much lower pressure.
If you get a chance look at the inside diameter of the outlet of a walbro 255 pump. It is tiny. It is approx. 1/8" ID. It also has a check valve that further restricts flow. Yet this small opening is capable of flowing 255lph. The inside diameter of the flex hose is 5/16." Inside diameter of the steel lines is 1/4" in some places. Believe it or not the plastic stock fuel lines are the least restrictive part of the system.. With the pressures that these pumps operate at they don't need -10 lines to move enough fuel. -10 lines in my opinion are for carburetors that operate at a much lower pressure.
as far as -10 lines being for carbed cars at lower pressures.. yes they work.. but on the same note.. on a turbo or supercharged car that will have a very large demand in a short period of time, the larger volume lines will allow more fuel to be moved on demand then the stock lines. for example your fuel pressure regulator is returning most fuel at idle.. but when accelerated hard into boost with 96lb/hr injectors.. your fuel curve for demand is going to keep those large squirters open for a much longer period of time. pressure alone is not alwys enough.. without the ability for the lines to support the volume needed to maintain pressure to the rail you run into fuel starvation problems and pressure drop.. pretty much the same as having an inefficient intercooler setup.. pressure going in will not always equal pressure being seen on the other end. the larger lines allow a greater volume of fuel to be moved maintaing proper rail pressure even under a turbochargers peak fuel demand between start spool and peak boost. as the injectors pulsewidth drastically increases.. it starts diminishing the existing rail pressure.. if the lines fail to support the volume needed.. you go boom.
Chris
03-05-2006, 09:24 PM
#62
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Join Date: Apr 2005
Location: Florence, Kentucky
Posts: 1,546
Re: Picture of my dual walbro setup
Originally Posted by NC-LT1
as far as -10 lines being for carbed cars at lower pressures.. yes they work.. but on the same note.. on a turbo or supercharged car that will have a very large demand in a short period of time, the larger volume lines will allow more fuel to be moved on demand then the stock lines. for example your fuel pressure regulator is returning most fuel at idle.. but when accelerated hard into boost with 96lb/hr injectors.. your fuel curve for demand is going to keep those large squirters open for a much longer period of time. pressure alone is not alwys enough.. without the ability for the lines to support the volume needed to maintain pressure to the rail you run into fuel starvation problems and pressure drop.. pretty much the same as having an inefficient intercooler setup.. pressure going in will not always equal pressure being seen on the other end. the larger lines allow a greater volume of fuel to be moved maintaing proper rail pressure even under a turbochargers peak fuel demand between start spool and peak boost. as the injectors pulsewidth drastically increases.. it starts diminishing the existing rail pressure.. if the lines fail to support the volume needed.. you go boom.
Chris
Chris
03-05-2006, 09:54 PM
#63
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Join Date: Aug 2001
Location: wilmington, NC USA
Posts: 252
Re: Picture of my dual walbro setup
well that statement "all the walbros can put out" is kind of an open ended statement as I mentioned before that the pumps can put out their limit of pressure or volume, but as pressure increases which running smaller lines will do, the volume of fuel the pump can move decreases.. so yes 1/4" line can handle all the walbros can put out pressure wise but they will not flow the same volume as a larger diameter fuel line can. the outlet of the fuel pump is quite irrelevent to its flow potential as it is rated with that opening.. we are trying to derive at the proper line sizing to get fuel 20+ feet to the engine where it is used.. every turn or bend in the line will increase pressure needed to get the fuel there, the size of the line will also play a key role.
kind of like this.. blow through a straw.. now blow through a garden hose... more pressure blowing through the straw, and your not going to move the same volume of air in the same given time as you can with the garden hose and the same pressure behind it.
if you are simply adding a pump to the stock single line, now you have two pumps competing to move fuel throught he same volume.. you are basically adding a pump to increase its ability to flow volume at the same pressure.. does it work.. yes.. you have two pumps overcoming the pressure and flowing twice the volume that one pump can flow at the same pressure.
the bottom line is 95% of the people on this board will never need the full potential of larger lines with twin pumps.. but there are a few who do and need even more then what twin walbros can support even with larger good flowing lines. in essence, it isn't realy a big deal to upgrade lines until you begin to see fuel pressure dropping near your torque or power peak.. when this happens.. upgrade the lines
when that maxes out.. get a weldon pump. when that maxes out.. be sure to carry dental records because if something goes wrong it may be the only way to identify you cause your putting more power to the ground then any person without some serious licensing should be allowed to have at their disposal. 
Chris
kind of like this.. blow through a straw.. now blow through a garden hose... more pressure blowing through the straw, and your not going to move the same volume of air in the same given time as you can with the garden hose and the same pressure behind it.
if you are simply adding a pump to the stock single line, now you have two pumps competing to move fuel throught he same volume.. you are basically adding a pump to increase its ability to flow volume at the same pressure.. does it work.. yes.. you have two pumps overcoming the pressure and flowing twice the volume that one pump can flow at the same pressure.
the bottom line is 95% of the people on this board will never need the full potential of larger lines with twin pumps.. but there are a few who do and need even more then what twin walbros can support even with larger good flowing lines. in essence, it isn't realy a big deal to upgrade lines until you begin to see fuel pressure dropping near your torque or power peak.. when this happens.. upgrade the lines
when that maxes out.. get a weldon pump. when that maxes out.. be sure to carry dental records because if something goes wrong it may be the only way to identify you cause your putting more power to the ground then any person without some serious licensing should be allowed to have at their disposal. Chris
03-06-2006, 07:14 AM
#64
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Join Date: Apr 2005
Location: Florence, Kentucky
Posts: 1,546
Re: Picture of my dual walbro setup
Originally Posted by NC-LT1
well that statement "all the walbros can put out" is kind of an open ended statement as I mentioned before that the pumps can put out their limit of pressure or volume, but as pressure increases which running smaller lines will do, the volume of fuel the pump can move decreases.. so yes 1/4" line can handle all the walbros can put out pressure wise but they will not flow the same volume as a larger diameter fuel line can. the outlet of the fuel pump is quite irrelevent to its flow potential as it is rated with that opening.. we are trying to derive at the proper line sizing to get fuel 20+ feet to the engine where it is used.. every turn or bend in the line will increase pressure needed to get the fuel there, the size of the line will also play a key role.
kind of like this.. blow through a straw.. now blow through a garden hose... more pressure blowing through the straw, and your not going to move the same volume of air in the same given time as you can with the garden hose and the same pressure behind it.
if you are simply adding a pump to the stock single line, now you have two pumps competing to move fuel throught he same volume.. you are basically adding a pump to increase its ability to flow volume at the same pressure.. does it work.. yes.. you have two pumps overcoming the pressure and flowing twice the volume that one pump can flow at the same pressure.
the bottom line is 95% of the people on this board will never need the full potential of larger lines with twin pumps.. but there are a few who do and need even more then what twin walbros can support even with larger good flowing lines. in essence, it isn't realy a big deal to upgrade lines until you begin to see fuel pressure dropping near your torque or power peak.. when this happens.. upgrade the lines when that maxes out.. get a weldon pump. when that maxes out.. be sure to carry dental records because if something goes wrong it may be the only way to identify you cause your putting more power to the ground then any person without some serious licensing should be allowed to have at their disposal.
Chris
kind of like this.. blow through a straw.. now blow through a garden hose... more pressure blowing through the straw, and your not going to move the same volume of air in the same given time as you can with the garden hose and the same pressure behind it.
if you are simply adding a pump to the stock single line, now you have two pumps competing to move fuel throught he same volume.. you are basically adding a pump to increase its ability to flow volume at the same pressure.. does it work.. yes.. you have two pumps overcoming the pressure and flowing twice the volume that one pump can flow at the same pressure.
the bottom line is 95% of the people on this board will never need the full potential of larger lines with twin pumps.. but there are a few who do and need even more then what twin walbros can support even with larger good flowing lines. in essence, it isn't realy a big deal to upgrade lines until you begin to see fuel pressure dropping near your torque or power peak.. when this happens.. upgrade the lines
when that maxes out.. get a weldon pump. when that maxes out.. be sure to carry dental records because if something goes wrong it may be the only way to identify you cause your putting more power to the ground then any person without some serious licensing should be allowed to have at their disposal. Chris
03-06-2006, 01:55 PM
#66
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Join Date: Jun 1999
Location: The Haven, Fl
Posts: 972
Re: Picture of my dual walbro setup
I got a kick out reading NC comments. I just got my -an 10 lines but they aren't for the fuel system though but OMG that's a huge azz line! I can't imagine anyone running something that big but I see I know people do.
Anything wrong using a 8-an line for the feed and a 6-an for the return instead w/ a dual fp setup? What are you guys doing exactly for the feed line in terms of putting a -an on there or are you cutting it off completely and doing like that pic shows?
Anything wrong using a 8-an line for the feed and a 6-an for the return instead w/ a dual fp setup? What are you guys doing exactly for the feed line in terms of putting a -an on there or are you cutting it off completely and doing like that pic shows?
03-06-2006, 07:54 PM
#67
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Join Date: Aug 1998
Location: Los Angeles, CA
Posts: 1,384
Re: Picture of my dual walbro setup
Originally Posted by ZBLKHELLRZR
I got a kick out reading NC comments. I just got my -an 10 lines but they aren't for the fuel system though but OMG that's a huge azz line! I can't imagine anyone running something that big but I see I know people do.
Anything wrong using a 8-an line for the feed and a 6-an for the return instead w/ a dual fp setup? What are you guys doing exactly for the feed line in terms of putting a -an on there or are you cutting it off completely and doing like that pic shows?
Anything wrong using a 8-an line for the feed and a 6-an for the return instead w/ a dual fp setup? What are you guys doing exactly for the feed line in terms of putting a -an on there or are you cutting it off completely and doing like that pic shows?
-B
03-08-2006, 01:38 AM
#70
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Join Date: Aug 1998
Location: Los Angeles, CA
Posts: 1,384
Re: Picture of my dual walbro setup
Originally Posted by atljar
So easy once you said it like that My final rendering.
The Four way switch may be a little tricky to find. It may also be called a DPDT Polarity Reverse switch. Just make sure it has 4 extermal terminals, not 6. Maybe 97WS6Pilot could share where he found his.
My final rendering.The Four way switch may be a little tricky to find. It may also be called a DPDT Polarity Reverse switch. Just make sure it has 4 extermal terminals, not 6. Maybe 97WS6Pilot could share where he found his.
I have a racetronix harness sitting on my desk and apparently they run a 10 gauge from the alternator to a relay, and there is a factory style plug that switches on the relay which feeds the pump with the 10 gauge wiring. Now how do we go about upgrading the stock wiring along with the 2nd pump?
-B
03-08-2006, 09:24 AM
#71
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Join Date: Aug 2001
Location: wilmington, NC USA
Posts: 252
Re: Picture of my dual walbro setup
I run mine parallel, I purchased two walbro kits and wired them so that both relays were activated by the factory wiring harness.. both pumps have their own wiring harness with 10 gauge wiring. the relayts are both activated at "key on", with the size lines and regulator I am runnning I did not notice any fuel pressure spikes, the system is capable of returning the fuel to the tank without rail pressure going crazy. stayed steady at as low as 30 psi rail pressure.
system is -8 feeds from pumps Y'd to a -10, and then split back to -8 at the rails and into a A1000 EFI aeromotive regulator with -10 inlet and outlet, return is a -6.
Chris
system is -8 feeds from pumps Y'd to a -10, and then split back to -8 at the rails and into a A1000 EFI aeromotive regulator with -10 inlet and outlet, return is a -6.
Chris
03-08-2006, 09:46 AM
#72
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Join Date: Feb 2001
Location: Cincinnati, Ohio
Posts: 3,068
Re: Picture of my dual walbro setup
Originally Posted by blown383
Are you using the stock wiring to power the first pump? Also what guage wire are you using to power the 2nd pump?
I have a racetronix harness sitting on my desk and apparently they run a 10 gauge from the alternator to a relay, and there is a factory style plug that switches on the relay which feeds the pump with the 10 gauge wiring. Now how do we go about upgrading the stock wiring along with the 2nd pump?
-B
I have a racetronix harness sitting on my desk and apparently they run a 10 gauge from the alternator to a relay, and there is a factory style plug that switches on the relay which feeds the pump with the 10 gauge wiring. Now how do we go about upgrading the stock wiring along with the 2nd pump?
-B
If you want to upgrade, I would copy what Racetronix did because they seem to have bunches of research into their stuff. So 10 gauge. You could go even bigger and its not going to hurt anything, 10 gauge off the top of my head seems a little small, but without knowing the amperage draw on the pumps, its a guess.
Run 10 gauge from the battery to the relays, and 10 gauge from the relays to the pumps. Ground both the pumps with 10 gauge, shorter the grounds the better.
The switch side of the relay can be small gauge, its just a turn on circuit.
As for running power from the alternator, instead of the battery...
You can get a little more voltage to the pumps like that, but with twin walbros I doubt you will need it. You also run into the problem of cranking/fuel pump prime then. Once again I dont have the wiring in front of me to see how they do it.
I also know that Racetronix sells a dual walbro intank setup, even though they dont advertise it. Maybe call them and see if you can buy the wiring harnes, and then add in the hobbs switch to that?
The switch side of the relays you can run something small
03-08-2006, 10:16 AM
#73
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Join Date: Jan 2003
Location: Breese, IL
Posts: 799
Re: Picture of my dual walbro setup
Originally Posted by NC-LT1
I run mine parallel, I purchased two walbro kits and wired them so that both relays were activated by the factory wiring harness.. both pumps have their own wiring harness with 10 gauge wiring. the relayts are both activated at "key on", with the size lines and regulator I am runnning I did not notice any fuel pressure spikes, the system is capable of returning the fuel to the tank without rail pressure going crazy. stayed steady at as low as 30 psi rail pressure.
system is -8 feeds from pumps Y'd to a -10, and then split back to -8 at the rails and into a A1000 EFI aeromotive regulator with -10 inlet and outlet, return is a -6.Chris
system is -8 feeds from pumps Y'd to a -10, and then split back to -8 at the rails and into a A1000 EFI aeromotive regulator with -10 inlet and outlet, return is a -6.Chris
Since my fuel pressure won't hit 60psi until about 17psi of boost, I run the standard pressure 255lph walbros (GSS307) that I picked up new for the whopping price of $60 a piece. You can always drop the pressure and up the injector too.
03-08-2006, 10:26 AM
#74
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Join Date: Apr 2005
Location: Florence, Kentucky
Posts: 1,546
Re: Picture of my dual walbro setup
I just wanted to update everyone on the testing of my dual walbro.
I did a couple of wide open throttle runs today. The A/F ratio is 12.0 from 2000 to 6200rpm. I didn't have to change my tune at all.
The second pump is coming on at 3-4 psi. The fuel pressure was 47 at 9 psi of boost.
My primary/secondary switch is working fine. I can switch it while I'm driving without even a hiccup. If I turn it to the center off position the car will die after about 5 seconds.
One thing interesting to note: My car idles at 38 psi on primary and it idles at 40psi on the secondary.
This could be caused by one of two things:
1. Bigger wiring and more amperage to the secondary
2. The secondary is new.
This is subjective, but the car just feels smoother at high boost/high rpm. I think it could be getting better cylinder distribution. This is just seat of the pants so who knows.
I did a couple of wide open throttle runs today. The A/F ratio is 12.0 from 2000 to 6200rpm. I didn't have to change my tune at all.
The second pump is coming on at 3-4 psi. The fuel pressure was 47 at 9 psi of boost.
My primary/secondary switch is working fine. I can switch it while I'm driving without even a hiccup. If I turn it to the center off position the car will die after about 5 seconds.
One thing interesting to note: My car idles at 38 psi on primary and it idles at 40psi on the secondary.
This could be caused by one of two things:
1. Bigger wiring and more amperage to the secondary
2. The secondary is new.
This is subjective, but the car just feels smoother at high boost/high rpm. I think it could be getting better cylinder distribution. This is just seat of the pants so who knows.
Last edited by 97WS6Pilot; 03-08-2006 at 10:36 AM.
03-08-2006, 11:59 AM
#75
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Join Date: Aug 1998
Location: Los Angeles, CA
Posts: 1,384
Re: Picture of my dual walbro setup
Originally Posted by atljar
(I just drew this, havent actually done the swap)
If you want to upgrade, I would copy what Racetronix did because they seem to have bunches of research into their stuff. So 10 gauge. You could go even bigger and its not going to hurt anything, 10 gauge off the top of my head seems a little small, but without knowing the amperage draw on the pumps, its a guess.
Run 10 gauge from the battery to the relays, and 10 gauge from the relays to the pumps. Ground both the pumps with 10 gauge, shorter the grounds the better.
The switch side of the relay can be small gauge, its just a turn on circuit.
As for running power from the alternator, instead of the battery...
You can get a little more voltage to the pumps like that, but with twin walbros I doubt you will need it. You also run into the problem of cranking/fuel pump prime then. Once again I dont have the wiring in front of me to see how they do it.
I also know that Racetronix sells a dual walbro intank setup, even though they dont advertise it. Maybe call them and see if you can buy the wiring harnes, and then add in the hobbs switch to that?
The switch side of the relays you can run something small
If you want to upgrade, I would copy what Racetronix did because they seem to have bunches of research into their stuff. So 10 gauge. You could go even bigger and its not going to hurt anything, 10 gauge off the top of my head seems a little small, but without knowing the amperage draw on the pumps, its a guess.
Run 10 gauge from the battery to the relays, and 10 gauge from the relays to the pumps. Ground both the pumps with 10 gauge, shorter the grounds the better.
The switch side of the relay can be small gauge, its just a turn on circuit.
As for running power from the alternator, instead of the battery...
You can get a little more voltage to the pumps like that, but with twin walbros I doubt you will need it. You also run into the problem of cranking/fuel pump prime then. Once again I dont have the wiring in front of me to see how they do it.
I also know that Racetronix sells a dual walbro intank setup, even though they dont advertise it. Maybe call them and see if you can buy the wiring harnes, and then add in the hobbs switch to that?
The switch side of the relays you can run something small
Here is a pictureIt looks like their regular harness thats doubled up with dual 20amp fuses, 40 amp relays and pig tails for the hobbs switch and fuel pumps. Now if I fabricated something like that I'm not too sure if its gonna cost $200.
-B