CHRISPY

exactly

2001WS6Vert

The regulator only bleeds off pressure. There is a straight shot from the pumps to the rails. If the pressure drops it is not from the regulator as it cannot add pressure only reduce it. If there is more pressure than the regulator spec (say 58lbs.) the regulator can maintain that pressure because there is available pressure above the regulated pressure. Once the pressure is below the set regulated pressure the regulator is out of the picture because there is no additional pressure to bleed off. If pressure drops below the regulated pressure there is no fuel being bypassed and all that is available is going to the rails. So the problem is in the lines.

Racetronix

iTrader: (2)

You only understand part of the theory here. You are missing one key element!

In this case the DP system is capable of producing enough volume at the required pressure at the tank end to overcome any frictional losses in the factory feedline in order to maintain stable rail pressure ONLY if the point of regulation is at the rail.

Dropping pressure is due to the lack of regulation at the fuel rail. If the return line was at the rail then pressure would be stable.

In other words the problem is with the position of the regulator in the LS1.

Q. If the pressure is stable at the back of the car under W.O.T. (58PSI) where the regulator is in an F-LS1 but the pressure drops at the fuel rail due to line drop WHERE do you suppose the problem is?

Q. Why don't '97 C5's with front-mounted FPR's experience the same level rail pressure loss as compared to later model C5's or F-LS1 cars with rear-mounted FPR's?

Q. How can the regulator adjust for line pressure drop (by backing up the feed line to the point of pressure relief at 58PSI) if it is located at the back of the car where the line drop is not occurring?

Go plumb a pressure gauge into the back of an F-LS1 car which has rail pressure drop and come back and tell us what you find!

Then relocate the regulator at the front of the car with a return line without upgrading the feedline and you will find that the pressure is stable which indicates adequate volume.

So in conclusion if you want to save a more than a few bucks relocate your regulator to the end of the fuel rail with a return line!!!

Blackbird

Great info. I know what I will be doing if it looks like I start running out of fuel with my new setup.

LASTLS1

iTrader: (7)

Great info! I'm in the middle of setting up a new fuel system ASAP!! I just want to buy the right stuff first.

qqwqeqwrqwqtq

I have an LT1, but it made 740 rwhp with dual intanks and stock lines/rails.

Right now it's at 868 rwhp with dual intanks, and has the stock fuel filter and some of the stock feed line. (-6 replaced the plastic under hood fuel line to connect to the aftermarket rails)

cablebandit

iTrader: (37)

2001WS6VERT-did you ever gut the dampener on the original fuel rail?

2001WS6Vert

No. I did the fuel rails 1st and then the lines with the Aeromotive regulator. No more fuel problems. The fuel pressure drop that I had after doing the rails did not seem to be enough to effect the power. I just didn't like to see any drop in pressure at all.

HUGGER ORANGE SS

iTrader: (2)

Dual Walbro's. Stock fuel Line, Stock fuel Filter, Stock Regulator. 621RWHP at 10 - 11psi of boost..

It's holding up perfect on my setup. With a single fuel pump, I start to run out of fuel at 5000 rpms. With both on 58psi all the time at WOT.

Here's a link to my Dyno Graph.
http://www.dynopro.com/mhhr_detail.asp?ID=5

Pictures of my Duel Pump Setup are in my Sig..

Regards,
Clint

1INSANEGTO

iTrader: (13)

Can the dual Walbro mod be performed on the 2004 GTO? I know this is a old thread but it was said it could be done but I have yet to see anyone who has done it.

1INSANEGTO

iTrader: (13)

Good pics Clint. Do you know if the Fuel bucket for your car would fit in a gto. I know there is a 8.1L fuel bucket mod but i do not know if you can fit 2 fuel pumps in it

Ryan K

iTrader: (11)

Dual Walbro's and 650rwhp with an automatic here. Stock lines, rails and regulator.

JASON 77

iTrader: (22)

bringin up a very old post. what are people using for a return line with the dual FP setups?

right now i have a single racetronics and rewire, running billet rails stock fuel line, filter and using the evap line as a return. FPR is mounted on top of that evap line, then in back of car the evap line has been disconnected from the rest of the cannister and dropped into tank via bulkhead fitting.

JoshuaGrooms83

iTrader: (2)

doing a little digging to revive some new info. wondering about this as well

Tirefire

iTrader: (1)

You can do what he's doing, eliminate EVAP and use it as return or buy a -8 line for supply and use your old factory supply as a return. It's a bigger line so it should support more fuel.. old post LOL

JoshuaGrooms83

iTrader: (2)

ok, im thinking im going to go the EVAP route since that aleviates buy more steel braided lines. alreadt bought 12 ft of 4an and 15 ft og 10an for more rear mount turbo build ive been doing... ug that was alot of money for some hose.

and yes lol quite an old post but thought to dig up one then to make a new one.



Ive decided to put the FPR on the stock fuel rail and then plumb a new dedicated fuel return 3/8 hardlline back to the stock plastic fuel return line and block off the t-block.

transamws6baby

iTrader: (6)

I will be running dual walbro pumps in my stock fuel bucket. some people say to go with show me speed's kit to save money. I have found out it is the same price as Racetronix dual walbro kit that come assembled with a billet Y vs. plastic. What do you think??? I have a single walbro 341 which I don't think I can use...correct?