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fuel system help!

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Old 10-05-2013, 11:10 AM
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Default fuel system help!

I'm swapping a carbureted lq4 into my Laguna . Ik I am going to have to sump my gas tank and run an in line fuel pump. My questions are , do I need a fuel pressure regulator? Do I need to run a return line? And what size fuel line should I run?
Old 10-05-2013, 11:14 AM
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What are you doing with this car? Cruiser? Drag racing? Street strip? Demolition derby? Get away car?

What is your set up details?
Old 10-05-2013, 11:45 AM
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Street strip pretty much. Want to be able to cruise and not have to worry about it and on occasion take it to test and tunes. It's a lq4 with PRC cnc ported ls6 stage 1 heads with an edelbrock victory Jr. Single plane intake and Idk what cam I'm going with yet. It weighs 3740 ibls has 411's and a 28 inch tall tire.
Old 10-05-2013, 12:22 PM
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You have many options, a Holley blue or black with a dead head regulator will work without a return line. Or you can step up to a more reliable setup as the aeromotive street and strip that requires a bypass or their pump that has a return built in.
Old 10-05-2013, 12:31 PM
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Based on what you are saying, I will tell you what most guys with set ups like that are running. Most are running the Aeromotive Street Strip pump.

Some guys like me are running the 3/8" steel line, others are running a 1/2" braided all the way from the tank. If you have a good pump, you can make quite a bit of power through a 3/8" fuel line. If you look in my signature, you will see what I mean.

I run a return line fuel system, but you do not have to.You can run what they call "dead head" style with no return line.

If you run no return line system, the best regulator for the money is the Holley 803:
http://www.summitracing.com/parts/hly-12-803/overview/

If you decide to run the return style system then you can run the Holley 803BP:
http://www.summitracing.com/parts/hl...03bp/overview/

I run a return style fuel system because it helps eliminate vapor lock in the Florida heat. Others run return style fuel systems because they have a high pressure fuel injection style fuel pump and most of those require return lines.

You do not have to run a return style system with the Aeromotive S/S pump.
Old 10-05-2013, 01:05 PM
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So a return style setup would probably be the most reliable?
Old 10-05-2013, 02:40 PM
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It is the most consistant pressure.
Old 10-05-2013, 07:59 PM
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Originally Posted by ZONES89RS
It is the most consistant pressure.
And not prone to vapor lock, as Tigger said earlier...
Old 10-05-2013, 08:06 PM
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And keeps the pump cooler.
Old 10-06-2013, 09:50 AM
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Thanks for the info that really helps
Old 10-06-2013, 01:13 PM
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Here is a pretty good link that describes some of the different things to think about when setting up a fuel system

http://www.centuryperformance.com/fo...ish-Tendencies

That automotive SS pump seems to be the popular option these days, but it is an awfully big pump (not to mention more expensive). If your LQ4 is near stock HP then you not only don't need but really don't want anything that big. All a pump that size is going to do is make more noise. It is also big enough you will pretty much be forced to a return style regulator or risk cavitation/vapor lock.

There are a lot of pumps around 90 to 100 gph that are internally regulated. This means you can run a single line from them to the motor with no regulator. While not the "best" set up in terms of fuel flow, regulation and vapor lock, it is a common set up that works and can save you some bucks.
Old 10-06-2013, 01:41 PM
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Originally Posted by Pop N Wood
Here is a pretty good link that describes some of the different things to think about when setting up a fuel system

http://www.centuryperformance.com/fo...ish-Tendencies

That automotive SS pump seems to be the popular option these days, but it is an awfully big pump (not to mention more expensive). If your LQ4 is near stock HP then you not only don't need but really don't want anything that big. All a pump that size is going to do is make more noise. It is also big enough you will pretty much be forced to a return style regulator or risk cavitation/vapor lock.

There are a lot of pumps around 90 to 100 gph that are internally regulated. This means you can run a single line from them to the motor with no regulator. While not the "best" set up in terms of fuel flow, regulation and vapor lock, it is a common set up that works and can save you some bucks.
I am not a fan of self regulated pumps. Pressure adjustments are a pain in the rear. And, the pressure is indexed at the pump and not at the carburetor. So, anything in between the pump and the carburetor can influence the pressure.
Old 10-06-2013, 10:15 PM
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The motor will not be stock I bought PRC cnc ported ls6 stage one heads for it I'm going to do a custom ground cam and an edelbrock victory Jr intake
Old 10-07-2013, 07:36 AM
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If it is in your budget, do a return style system. Its better for the pump and keeps options open for down the road. Im running a Fast EZ efi system on my 72 Camaro with the Aeromotive HP700 pump. Im running at 43psi with the EFI, BUT if I wanted to change over to a carb, it is a simple swap. The pump will work with either one, at low or high pressure, and with the return style system, its not taxing the pump to do big PSI swings between carb and EFI. The only thing I would have to change to go carb would be a low pressure style regulator. And like Zone said, you have much more consistent pressure without the" dead head surge".
Old 10-07-2013, 08:24 AM
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Originally Posted by speedtigger
I am not a fan of self regulated pumps. Pressure adjustments are a pain in the rear. And, the pressure is indexed at the pump and not at the carburetor. So, anything in between the pump and the carburetor can influence the pressure.
Yeah, return style is "better", I run one myself (with a 140 gph pump no less). Yet the fact remains most OEM sets ups and lots of hot rods successfully run with no return line or at best a dead head regulator.

My only point about the motor being near stock is the higher the HP the more effort that needs to go into the fuel system. The OP should read that link I posted, they cover all the options in good detail there.
Old 10-07-2013, 09:47 AM
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I have my edelbrock quiet flo 160 gph pump to a dead head regulator. It's not quiet but I've never noticed the gauge fluctuate or bounce any. I have a quickfuel regulator and 8an or 10an line I forget which it is. I'd think with a return style regulator I could see a sound change on the pump but I haven't been too worried as this system hasent let me down yet.



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