Plumbing in a Fuel Pressure Regulator
Thread Starter
Joined: Mar 2003
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From: Hamilton Ontario
Plumbing in a Fuel Pressure Regulator For those that have a external fuel pressure regulator. Where did you locate it, what did you run for a return fuel line. Steel, braided or just a reinforced rubber gas line. I wouldn't expect the return line wouldn't have to handle that much pressure.
I posted this in the fuel section but I thought I may get more answers in a section where a external FPL would see more use.
I posted this in the fuel section but I thought I may get more answers in a section where a external FPL would see more use.
I always mount mine under the hood somewhere. I run braided line, but any line rated for the pressure is fine. The return will flow but since its just dumping back into the tank or cell, there really isn't any pressure on it.
I put mine directly on the rail, made a little braket to support it.
I used fragola push lock hose for fuel line.
I used fragola push lock hose for fuel line.
Use these threaded ones and you will never have an issue. The ones with plastic lock like the stock lines pop off on some people.
http://www.summitracing.com/parts/rus-644123/overview/
I'm about to do mine and I'm going to try and cheat. Not sure if it will work, but I'm going to use these fittings and try and use the 5/16" emissions line as my return.
http://www.summitracing.com/parts/rus-644123/overview/
I'm about to do mine and I'm going to try and cheat. Not sure if it will work, but I'm going to use these fittings and try and use the 5/16" emissions line as my return.
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I think the best place for a reg is after the rails. Think about it ,all a reg is is a restriction in the line to keep pressure up. On my build I'm using -8 to the rails, y fitting into -6 to each side of rails, -6 to reg, -6 return .this will insure full volume to injectors. When placed before the rails, the higher the fuel pressure, the lower the volume.
I made a mount 6" off the firewall for the reg, ran a #10 pump to fuel rail, #8 cross over, and back out to reg.-I ran a #8 return-prob over kill for what I have, used reg quality stainless braided
Kind of a crappy picture, lol
Kind of a crappy picture, lol
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Verdad Gallardo TECH Fanatic
Joined: Jan 2010
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From: sarasota fl
Use these threaded ones and you will never have an issue. The ones with plastic lock like the stock lines pop off on some people.
http://www.summitracing.com/parts/rus-644123/overview/
I'm about to do mine and I'm going to try and cheat. Not sure if it will work, but I'm going to use these fittings and try and use the 5/16" emissions line as my return.
http://www.summitracing.com/parts/rus-644123/overview/
I'm about to do mine and I'm going to try and cheat. Not sure if it will work, but I'm going to use these fittings and try and use the 5/16" emissions line as my return.
I ended up just going with an push lock and 1/2 feed line
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Joined: Jan 2010
Posts: 1,074
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From: sarasota fl
I think the best place for a reg is after the rails. Think about it ,all a reg is is a restriction in the line to keep pressure up. On my build I'm using -8 to the rails, y fitting into -6 to each side of rails, -6 to reg, -6 return .this will insure full volume to injectors. When placed before the rails, the higher the fuel pressure, the lower the volume.
(But somtimes your motor came with returnless style fuel rails lol)
I'm also using -8 with dual walbros, hopefully it works out for me,
Many have done it before with no issues, however we know this is not "ideal"
I like the idea of running the supply line to each rail separate, or with a Y between the FPR and the rails. I myself am new to the EFI setups, but it seems for a big hp engine with really high flow rates, if you run the rails with 1 supply and then a crossover line for the other rail, you could have some loss of pressure and or flow to the last injector in the series and maybe even before that last one. So with the Y each rail is only supplying 4 injectors instead of the one inlet supplying 8.
Thoughts? Or is this overthinking it?
Thoughts? Or is this overthinking it?
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Joined: Jan 2010
Posts: 1,074
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From: sarasota fl
I like the idea of running the supply line to each rail separate, or with a Y between the FPR and the rails. I myself am new to the EFI setups, but it seems for a big hp engine with really high flow rates, if you run the rails with 1 supply and then a crossover line for the other rail, you could have some loss of pressure and or flow to the last injector in the series and maybe even before that last one. So with the Y each rail is only supplying 4 injectors instead of the one inlet supplying 8.
Thoughts? Or is this overthinking it?
Thoughts? Or is this overthinking it?
I like the idea of running the supply line to each rail separate, or with a Y between the FPR and the rails. I myself am new to the EFI setups, but it seems for a big hp engine with really high flow rates, if you run the rails with 1 supply and then a crossover line for the other rail, you could have some loss of pressure and or flow to the last injector in the series and maybe even before that last one. So with the Y each rail is only supplying 4 injectors instead of the one inlet supplying 8.
Thoughts? Or is this overthinking it?
Thoughts? Or is this overthinking it?
If they can survive going 10K RPM's my stuff should survive at 6500, lol
Carbs are completely different and also very low pressure. Usually below 6psi. They do flow well but its only 2 bowls being supplied, not 8 injectors. So the carb does push out a lot of fuel volume equal to the fuel if it were an EFI system. But there is flow loss and pressure loss when you run any length and making turns. Its psychometrics, or pressure and flow loss factors.
Carbs are completely different and also very low pressure. Usually below 6psi. They do flow well but its only 2 bowls being supplied, not 8 injectors. So the carb does push out a lot of fuel volume equal to the fuel if it were an EFI system. But there is flow loss and pressure loss when you run any length and making turns. Its psychometrics, or pressure and flow loss factors.