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engine swap, higher pressure bolt in fuel pressure options?

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engine swap, higher pressure bolt in fuel pressure options?

Old 02-11-19, 09:29 PM
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engine swap, higher pressure bolt in fuel pressure options?

hey all, i just swapped an F20 into my fb. yeah yeah shoot me w/e, i went from 12a, to half bridge 13b to pport 13b.
anyway, i need much more fuel pressure then what the stock gslse and all other trim sa/fb's supply but we have it easy! inline fuel pumps only!
SO my question IS, what upgraded bolt in fuel pumps are out there ? i feel like this is easily google-able but i wanted to ask anyway. probably just look for an inline that supplies my desired fuel pressure..
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Old 02-11-19, 11:31 PM
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What pressure do you need? How much fuel (GPH) do you need?

Why not just weld in a solution to your tank? The problem with inline is that you're going to have to upgrade the lines going into the tank to prevent hose collapsing.
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Old 02-12-19, 08:55 AM
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Stock GSL-SE pump is actually really overbuilt. It will easily flow what an F20 requires at its pressure.

I used to run Bosch roller pumps, but anymore I just started using cheapo Ford truck inline pumps. They cost a lot less and last just as long, and would feed my 260-odd horsepower bridge port just fine. Summit repackages them as EFI swap pumps and sells them for $100-ish, but you can buy them on Rock Auto for far, far less.

I do have a mildly extensive surge tank in place, though. A generic low-pressure fuel pump feeds a cylindrical tank vertically mounted in front of the rear axle, and at the bottom of that is the feed to the high pressure pump. The return from the engine also feeds this surge tank and the very top has a port to return to the fuel tank. It turns out that what my biggest problem was with eating pumps was when the pump would suck air in left corners below half tank, or going uphill with a low tank. The surge tank allows me to run the car until the main tank is practically dry (you can hear the low pressure pump rattling when it sucks air!) and the main pump never sucks air.
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Old 02-16-19, 08:46 AM
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so i researched it, looks like i only need about 40-50, which is less than a stock gslse puts out i believe?
are gsl/gs/base model fb's have the same lines as gslse's ? as far as line collapsing goes
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Old 02-16-19, 10:53 AM
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Not certain what line collapsing goes means? GS,GSL have 8mm feed and 6mm return lines. SE has 8mm feed and return lines. You need to have at least SE spec fuel lines. Without looking into fuel pressure/volume requirements for powerplant you're using,i would suspect you would need 3/8"-6-AN fuel and supply lines from tank to fuel rail,more so if fuel injectors used are not oe spec or any other components of fuel system on engine are modified.
Trying to use undersize and dissimilar feed and supply lines only leads to driveability,tuning issues and an unhappy fuel pump living a short life. Fact,not my opinion. Look thru any engine swap that went from carb fuel system to FI with running problems,noisy short lived fuel pump issues and the common denominator is mismatched undersize supply and return lines.
You will need to address fuel slosh with less than 1/2 full tank causing engine stalling,hesitation,surging as pickup tube is uncovered and sucks air-makes fuel pump very unhappy.

There will be no "bolt in" solution to this,fabrication will be necessary. Regarding fuel pump selection...criteria for choosing pump is not to attempt to choose one based on average running pressure of system as pressure doesn't remain static in different driving scenarios. In acceleration or anything other than idling and light cruise,the fuel system needs to enrich air/fuel mixture and this is done by using a map or vacuum signal to ecu and fuel pressure regulator in fuel rail that all FI systems have. When manifold vacuum drops,the vacuum diaphragm in regulator restricts the amount of fuel volume being returned to the tank which raises line pressure which richens air/fuel mix along with ecu upping injector duty cycle on time to fine tune fuel injected as required by amount of power needed. Average fuel rail pressure increase in this scenario is 12-15 psi. A fuel pump selected solely on basis of static fuel pressure will neither be able to supply increased pressure and volume for anything other than idle/cruise situations.
Every factory FI system design includes a pump that develops considerably more pressure/volume than engine will need in any particular scenario to allow oe manufacturers to design a fuel map to control injectors to feed the engine what it needs in those scenarios and basic fuel pressure is controlled by fuel pressure regulator in fuel rail which determines rail pressure in all operating conditions. So...selecting a fuel pump should be done by considering what it can flow. This spec is seen as GPH gallons per hour or LPH liters per hour. When selecting a pump for a custom setup always err on more volume than less. Choosing a pump without a comfortable GPH-LPH rating will lead to leaning out air/fuel mixture at full throttle situations as the pump is maxed out which can be disastrous in other than NA applications. Selecting a pump with a higher than anticipated need will afford that comfort margin,allow flexibility in ecu mapping and unneeded/unused fuel will be directed back to fuel tank.

Again without knowledge of oe fuel pump pressure/volume specs,which could be easily found with some research,a rough guess from displacement of engine you're using would be 190-225 lph pump. If you anticipate running it hard,or mods to injectors or fuel rail/regulator go with higher lph#. Pump PJ recommends suits your needs well.

Strongly recommend you read thru chuylers fuel hard lines post in this forum from beginning to end. Will certainly provide you with what you need to do and what not to do for a proper FI conversion.

Last edited by GSLSEforme; 02-16-19 at 10:56 AM.
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Old 02-16-19, 09:15 PM
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Originally Posted by GSLSEforme View Post
Not certain what line collapsing goes means? GS,GSL have 8mm feed and 6mm return lines. SE has 8mm feed and return lines. You need to have at least SE spec fuel lines. Without looking into fuel pressure/volume requirements for powerplant you're using,i would suspect you would need 3/8"-6-AN fuel and supply lines from tank to fuel rail,more so if fuel injectors used are not oe spec or any other components of fuel system on engine are modified.
Trying to use undersize and dissimilar feed and supply lines only leads to driveability,tuning issues and an unhappy fuel pump living a short life. Fact,not my opinion. Look thru any engine swap that went from carb fuel system to FI with running problems,noisy short lived fuel pump issues and the common denominator is mismatched undersize supply and return lines.
You will need to address fuel slosh with less than 1/2 full tank causing engine stalling,hesitation,surging as pickup tube is uncovered and sucks air-makes fuel pump very unhappy.
The 8mm (or less I am using an SA tank) feed line wasn't enough for my purposes. With a comp 140 Mallory pump I had to downsize the inlet to match the rubber hoses coming from the tank and feeding the pump. I kept burning up brushes in that pump (at the time I thought it was a bad design). I put in a 3/8 line (a wee bit bigger) and used a different pump (msd2225); now I have plenty of fuel. I passed the pump over to a buddy of mine and when he saw the downsized junction on the Comp 140 he said that line collapsing will cause extra strain on a fuel pump. If you use a large pump with a small line (inappropriately sized for the pump) the pump will suck the line down and collapse it. It happens a lot in older 911's with their dry sump oil system (only on a much larger and more viscus scale).

Seemed logical and my issues were solved with a larger inlet hose; so I just figured that was my issue. I don't know if I'm using the right terminology.

OP: if you have a wrecked S2000 and you are not highly modifying the S2000 engine why not rob the fuel tank top out of it and weld it in? No guess work involved there. I'm with GSLSEforme on this one.
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