Conversion to rail mounted regulator
Thread Starter
Racer
Joined: Jan 2003
Posts: 405
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From: Coconut Creek FL
Conversion to rail mounted regulator
I am converting my '99 to a fuel system with a boost referenced rail mounted regulator. I intend to use a Racetronix wired Walbro 255lph in-tank, plumbed into a Walbro GSL 392 in-line. (I will also be using a volt booster.) Plumbing the pressure side seems pretty straightforward. My concern is regarding the return...it appears that there is an existing return line plumbed into my factory system to return fuel from the stock filter back to the tank(s). Can I simply plumb my new return, from the new rail mounted regulator, back into that existing return line at the rear of the car? Will there be any issues with the fuel transfer/readings of the C5's dual tank system if I do it this way?
Thanks,
Rob
Thanks,
Rob
Safety Car
Joined: Apr 2004
Posts: 3,932
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From: Hayward California
My system is similar to what you are planning. From the tank I ran new lines from the fuel filter (non-regulated). It feeds into a regulator that forces the intank pump to see 50psi. and from there feeds the inline. From there the rails.
The return (2nd regulator now at the rails) basically uses the stock hard line (top of the drivers manifold) which leads back to the filter area and is extended back to the tank using the stock return fitting.
Prior to using the regulator btwn the two pumps I ran out of gas w/ 1/8th of tank showing on my guage. Long story, short it fired up as soon as I put gas in her and when I filled it up, the guage wasn't wrong. With the help of xtream1, who is doing and experienced the same, I tried out the requlator and I can now run her to fumes and know I''ve gotten the last drop.
The return (2nd regulator now at the rails) basically uses the stock hard line (top of the drivers manifold) which leads back to the filter area and is extended back to the tank using the stock return fitting.
Prior to using the regulator btwn the two pumps I ran out of gas w/ 1/8th of tank showing on my guage. Long story, short it fired up as soon as I put gas in her and when I filled it up, the guage wasn't wrong. With the help of xtream1, who is doing and experienced the same, I tried out the requlator and I can now run her to fumes and know I''ve gotten the last drop.
Last edited by magdc5; Jun 14, 2005 at 04:03 PM.
Drifting
Joined: Apr 2002
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From: Stealth So Cal GOCC ...comming to invade your neighborhood soon
Thanks Arnel,
I finally installed/tested my return regulator also and seem to have solved the couple of issues that I had left. All is good and am glad to hear yours is also.
I finally installed/tested my return regulator also and seem to have solved the couple of issues that I had left. All is good and am glad to hear yours is also.
Safety Car
Joined: Apr 2004
Posts: 3,932
Likes: 8
From: Hayward California
An upgraded intank and a BAP w/ a return at the rails is good for 600plus. MDMC's return system is working with 800plus at the wheels.. that's with no inline, just a MSD BAP and the intank upgrade.
Two reasons why I use an inline.. I plan on having a surge tank up front in the near future and I didn't want the BAP on the intank, or one at all. I also want overkill on the fuel if and when I want 800plus at the wheels.
Two reasons why I use an inline.. I plan on having a surge tank up front in the near future and I didn't want the BAP on the intank, or one at all. I also want overkill on the fuel if and when I want 800plus at the wheels.
Drifting
Joined: Apr 2002
Posts: 1,941
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From: Stealth So Cal GOCC ...comming to invade your neighborhood soon
Originally Posted by magdc5
An upgraded intank and a BAP w/ a return at the rails is good for 600plus. MDMC's return system is working with 800plus at the wheels.. that's with no inline, just a MSD BAP and the intank upgrade.
Two reasons why I use an inline.. I plan on having a surge tank up front in the near future and I didn't want the BAP on the intank, or one at all. I also want overkill on the fuel if and when I want 800plus at the wheels.
Two reasons why I use an inline.. I plan on having a surge tank up front in the near future and I didn't want the BAP on the intank, or one at all. I also want overkill on the fuel if and when I want 800plus at the wheels.
Thread Starter
Racer
Joined: Jan 2003
Posts: 405
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From: Coconut Creek FL
Originally Posted by hpcubed
I have a 99 as well. Do you really need a second in-line pump. What if I just ran a walbro intank to the rail mounted reg. then return to the stock return? How much fuel pressure are you guys running?
I'll be feeding a very thirsty 402 TT, so I'm going to need more than a single 255 in-tank. There is a Bosch 310 in-tank that some people are using, but it isn't a direct replacement. Being boost referenced, my fuel pressure will be ~70psi. A Walbro 255 in-tank, plumbed into their GSL 392 in-line (which is also rated 255lph), flows about 70gph @ 70psi, pulling a total of 15.4 amps (@ 13.5 volts)...sounds like an easy solution. With a volt booster, it should be able to support 800+ hp to the wheels.
What are you guys using for a regulator between the pumps?
Last edited by FRC Rob; Jun 16, 2005 at 09:38 AM.
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Safety Car
Joined: Apr 2004
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From: Hayward California
Originally Posted by FRC Rob
What are you guys using for a regulator between the pumps?
I'm using an edelbrock (EDL 1729) unit I had running around.. overkill since all you want is a steady 50psi. no boost reference or more than a single feed and return necessary.
Pro
Joined: Apr 2001
Posts: 589
Likes: 0
From: Torrance CA
Originally Posted by magdc5
My system is similar to what you are planning. From the tank I ran new lines from the fuel filter (non-regulated). It feeds into a regulator that forces the intank pump to see 50psi. and from there feeds the inline. From there the rails.
The return (2nd regulator now at the rails) basically uses the stock hard line (top of the drivers manifold) which leads back to the filter area and is extended back to the tank using the stock return fitting.
Prior to using the regulator btwn the two pumps I ran out of gas w/ 1/8th of tank showing on my guage. Long story, short it fired up as soon as I put gas in her and when I filled it up, the guage wasn't wrong. With the help of xtream1, who is doing and experienced the same, I tried out the requlator and I can now run her to fumes and know I''ve gotten the last drop.
The return (2nd regulator now at the rails) basically uses the stock hard line (top of the drivers manifold) which leads back to the filter area and is extended back to the tank using the stock return fitting.
Prior to using the regulator btwn the two pumps I ran out of gas w/ 1/8th of tank showing on my guage. Long story, short it fired up as soon as I put gas in her and when I filled it up, the guage wasn't wrong. With the help of xtream1, who is doing and experienced the same, I tried out the requlator and I can now run her to fumes and know I''ve gotten the last drop.
Last edited by hpcubed; Jun 16, 2005 at 07:10 PM.
Safety Car
Joined: Apr 2004
Posts: 3,932
Likes: 8
From: Hayward California
I'm using the Aeromotive rails and wouldn't use anything else. I've read it's cleaner looking than some of the others.
HOWEVER!!!!!! I'm not sure of the others but I'm thinking it's the case with all of them.. If you're looking to use fittings on the ends towards the back of the motor, you will need to cut the fiberglass which is the water channel for the wipers.
The fitting from AN line to the stock hardlines you can get from => http://www.performanceplumbing.com/New_Products.html => part# 5800
Other than that, the transfer to and from the passenger side tank is on the existing FEED line from the tank to the filter, if you leave that line in place you should be good.
HOWEVER!!!!!! I'm not sure of the others but I'm thinking it's the case with all of them.. If you're looking to use fittings on the ends towards the back of the motor, you will need to cut the fiberglass which is the water channel for the wipers.
The fitting from AN line to the stock hardlines you can get from => http://www.performanceplumbing.com/New_Products.html => part# 5800
Other than that, the transfer to and from the passenger side tank is on the existing FEED line from the tank to the filter, if you leave that line in place you should be good.
Pro
Joined: Apr 2001
Posts: 589
Likes: 0
From: Torrance CA
Great, thanks for the information. I think that I will try to set up my fuel system before going FI.
Have you ever seen these rails? I believe it comes with the OEM fuel line adapter.
http://www.lmperformance.com/5683/68.html
Also, can the coil covers fit or be modified to fit over these rails?
Have you ever seen these rails? I believe it comes with the OEM fuel line adapter.
http://www.lmperformance.com/5683/68.html
Also, can the coil covers fit or be modified to fit over these rails?
Last edited by hpcubed; Jun 17, 2005 at 04:14 PM.
Pro
Joined: Apr 2001
Posts: 589
Likes: 0
From: Torrance CA
Originally Posted by magdc5
sorry I haven't had coil covers in a long while... I would relocate the coils for a different look and it's cooler that way for the coils.
those rails look good..
those rails look good..
Thread Starter
Racer
Joined: Jan 2003
Posts: 405
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From: Coconut Creek FL
I tried doing some further research, and some people have indicated that the fuel system likes to see about 4 bars (4bars x 14.7psi = 58.8psi) head pressure out of the in-tank pump, in order for the internal fuel transfer system to syphon over properly. Although, the 4 bar number doesn't appear to be absolute, since the systems with 50# regulators are working fine. Has anybody tried running an in-tank into a '99-'03 regulated fuel filter, and then put an in-line ahead of that? Seems like that would solve the problem in one unit, instead of using separate regulators & filters in back. Also, does anybody see an issue using a "Y" from the front & rear regulator return lines into the factory return line? (Wondering if last foot or two of the factory system could handle the combined returned volume?)
Edit: On second thought, there's going to have to be a pressure differential between the pumps...I'd need the rail regulator set higher than the one in back. I guess that's why they've been setting 'em at 50#. (By the time I add in the cost of the second regulator, I'm getting closer to the cost of a Bosch 310lph in-tank...maybe that's not such a bad option afterall?)
Edit: On second thought, there's going to have to be a pressure differential between the pumps...I'd need the rail regulator set higher than the one in back. I guess that's why they've been setting 'em at 50#. (By the time I add in the cost of the second regulator, I'm getting closer to the cost of a Bosch 310lph in-tank...maybe that's not such a bad option afterall?)
Last edited by FRC Rob; Jun 20, 2005 at 11:22 AM.
Safety Car
Joined: Apr 2004
Posts: 3,932
Likes: 8
From: Hayward California
With a single Bosch 310 intank you'll still need to figure in the cost of a BAP..
Check this out if you hadn't already:
Link comparing intanks and intanks w/ inlines
Bottom line is w/ the addition of an inline, flow is increased and more easily sustained when needing above 70psi. Regarding the amperages required... it shares the load so that neither pump works nearly as hard.
Check this out if you hadn't already:
Link comparing intanks and intanks w/ inlines
Bottom line is w/ the addition of an inline, flow is increased and more easily sustained when needing above 70psi. Regarding the amperages required... it shares the load so that neither pump works nearly as hard.
Instructor
Joined: Aug 2003
Posts: 241
Likes: 0
You cannot install an inline on a FFS fuel system, unless you install a regulator/return line that will sense the fuel pressure that builds between the inline and injectors. What occurs is that pressure builds up between the inline and the injectors. The in-tank regulator only sees the pressure between the pumps, and not 'ahead' of the inline. Eventually, the pressure rises to 120+++ and your injectors lock up. Reason being is the inline pump is only flowing one-way..
Hope I explained that right....but most importantly, this is not theory. I just tried this last month !
My 408 stroker is STARVING for fuel, the in-tank cannot keep up with the 42lbers (which flow 50lbs at 60psi) I am currently installing a BAP. I am going with the new Racetronics fuel pump harness and Kenne Bell BAP.
Hope that helps!
Hope I explained that right....but most importantly, this is not theory. I just tried this last month !
My 408 stroker is STARVING for fuel, the in-tank cannot keep up with the 42lbers (which flow 50lbs at 60psi) I am currently installing a BAP. I am going with the new Racetronics fuel pump harness and Kenne Bell BAP.
Hope that helps!
Safety Car
Joined: Apr 2004
Posts: 3,932
Likes: 8
From: Hayward California
Originally Posted by FRC Rob
Has anybody tried running an in-tank into a '99-'03 regulated fuel filter, and then put an in-line ahead of that? Seems like that would solve the problem in one unit, instead of using separate regulators & filters in back. Also, does anybody see an issue using a "Y" from the front & rear regulator return lines into the factory return line? (Wondering if last foot or two of the factory system could handle the combined returned volume?)
Edit: On second thought, there's going to have to be a pressure differential between the pumps...I'd need the rail regulator set higher than the one in back. I guess that's why they've been setting 'em at 50#. (By the time I add in the cost of the second regulator, I'm getting closer to the cost of a Bosch 310lph in-tank...maybe that's not such a bad option afterall?)
Edit: On second thought, there's going to have to be a pressure differential between the pumps...I'd need the rail regulator set higher than the one in back. I guess that's why they've been setting 'em at 50#. (By the time I add in the cost of the second regulator, I'm getting closer to the cost of a Bosch 310lph in-tank...maybe that's not such a bad option afterall?)
Safety Car
Joined: Apr 2004
Posts: 3,932
Likes: 8
From: Hayward California
Originally Posted by PowerKraus
You cannot install an inline on a FFS fuel system, unless you install a regulator/return line that will sense the fuel pressure that builds between the inline and injectors. What occurs is that pressure builds up between the inline and the injectors. The in-tank regulator only sees the pressure between the pumps, and not 'ahead' of the inline. Eventually, the pressure rises to 120+++ and your injectors lock up. Reason being is the inline pump is only flowing one-way..
Hope I explained that right....but most importantly, this is not theory. I just tried this last month !
My 408 stroker is STARVING for fuel, the in-tank cannot keep up with the 42lbers (which flow 50lbs at 60psi) I am currently installing a BAP. I am going with the new Racetronics fuel pump harness and Kenne Bell BAP.
Hope that helps!
Hope I explained that right....but most importantly, this is not theory. I just tried this last month !
My 408 stroker is STARVING for fuel, the in-tank cannot keep up with the 42lbers (which flow 50lbs at 60psi) I am currently installing a BAP. I am going with the new Racetronics fuel pump harness and Kenne Bell BAP.
Hope that helps!