Tpx

So I have a HSR, with the provided fuel rails and crossover tubing from the driver fuel rail to the passenger fuel rail. It links the front of the two rails together. The fuel is delivered to the rear end of the driver side rail. Anyone who has a HSR knows all about it just look under your hood if confused.

Anyway, I am going to get rid of the rubber lines that are poorly routed with braided lines, AN fittings, and a new regulator from aeromotive. I want to rip out all the existing tubing and regulator so that I just have the fuel hardlines that end on the drivers side frame rail, and the fuel rails on my intake with no crossover.

Then I will plumb up my fuel pressure regulator on the frame rail next to the hardlines and plumb the return right there, since it seems reasonable, run a Y block after the regulator to split the fuel lines into two, and then run separate fuel lines to the front of each fuel rail.

This, to me, sounds more logical due to the travel the fuel has to do if it wants to get to the last injector in the line: it has to go from the drivers side rail, past 4 injectors, to the crossover pipe/hardline, back across 3 more injectors, just to reach the last injector. Doesn't sound sensible.

Will there be any problems splitting the fuel lines into two, so that the rails each get their own line straight from the regulator? Or should I run two regulators one for each rail? Are there going to be any issues removing the crossover pipe between fuel rails? Is the frame rail a bad place to mount a regulator?

Thanks for your input.

vetteoz

iTrader: (13)

Makes no difference; all injectors are seeing the same pressure which is all that counts.

Sounds like a lot of work for no gain
Usual setup with EFI is to have reg after rails ; not before ( as with carbs )
The regulator works best when the rails are between it and the fuel pump. Drops in pressure due to acceleration are compensated for more quickly.

High performance dual feed systems split supply line to each rail and then join lines to single reg after rails

Tpx

Well I was thinking under WOT the fuel might not be able to make it to that last injector at full pressure, but under a duel feed system at most only 3 injectors are sucking fuel before that last one. Since they fire in batch mode, I thought this was a better solution.

I was thinking of putting the regulator after the rails, but wasn't sure that was a smart idea. If others have done it in high performance situations then that's good enough for me. I like it that way more anyway. Thank you for sharing your experience/knowledge on this subject.

86White_T/A305

The way mine is setup is that the fuel feed line goes into the rear of the passenger side rail,then crossover tube to the driver rail,then the kirban regulator and out to the return line. At 47psi of pressure I dont see any issues,i cut the factory lines at the frame and flared the ends and rain steel braided lines upto the hsr.

Orr89RocZ

iTrader: (20)

It does make a slight difference in fuel delivery on higher hp applications to run parrallel lines instead of in-series like normal fuel line routing is done, or atleast thats what i've heard. GMhightech had an article on this for an LT1 and says fuel pressure distribution across the rails suffers with in-series routing on applications over 350 hp.

Not sure how true that is, because if the fuel pump is strong enough it will flow enough fuel to keep pressure in the system and negate any fuel injector consumption losses. 350hp LT1 isnt consuming that much fuel and there are guys making well over that on stock lines.

May become an issue if you are pushing the limits of the hp potential that the rails can provide however. If the rails are large enough then it shouldnt matter but i guess when you get to that point of maxing out the HSR fuel rails, which may be 1000hp on those rails, you could perhaps suck the one bank dry or cause a large pressure drop between the first rail and the second. Not really sure. Makes sense to me if you had enough fuel pump, you would beable to provide fuel pressure no matter what the consumption rate is.

If you want to do two separate lines, do the regulator after the rails. Split feed line into 2, feed rails, and then y back into the reg then single line to return on tank.

Tpx

Thanks for all the comments, it's a great help to me to throw up a theory I had then see it confirmed or shot down by others who had done or heard of the same idea. Every shared experiance helps.

So far looks like I was wrong about pressure drop, after testing this while driving uphill at full throttle there was only a 3 psi drop on the second rail, which isn't drastic.

In any case, I will take the consensus advice and run the reg after the rails utilizing two Y blocks one before one after.

vetteoz

iTrader: (13)

You can compact the installation by installing a Aeromotive # 13301 reg ( very compact ) directly on the end of one fuel rail and running the return line from other rail into it.
Return line comes out bottom and has provision to mount gauge on one of the spare ports
Saves having the 2nd Y fitting
#13301 comes with two springs; one for carb and one for injection
(20 - 65 psi )

breynolds

iTrader: (1)

My question is this:

If you decide to go this route and use an aftermarket FPR that mounts on your firewall or something like that, what do you do about the FPR that bolts to the fuel rail? Do they make something to plug the hole?

Orr89RocZ

iTrader: (20)

if you wanted to run an external regulator, dont buy the holley rails. I believe the edelbrock Victor E EFI rails will bolt up just fine. It looked like it fit fine on my HSR when I had the two side by side.

Else have someone weld a plug in there.

breynolds

iTrader: (1)

I understand that portion, but that doesn't answer MY question. Is there no easy way to do this for the person that already has the Holly rails?

Orr89RocZ

iTrader: (20)

I said you can have someone weld in a plug I dont think there is a way to do this other than make a plug that simulates the tip of the regulator with an O-ring. Something like a plate with a pipe nipple on it and an o-ring to clog up the rail hole.

Maybe you can hollow out a cheap holley regulator and run thru it. I think making a plug would be the best cleanest option, but if thats unsuccessful then try to resale the holley rails and go aftermarket with another setup.

I dont think you will beable to get a tap in there to make it a threaded plug so that option may be out.

I was in this predicament when i went with my dual pump fuel system and external reg. I looked at welding a plug and tapping but decided to ditch the HSR completely. Wish I would have tried it again.

vetteoz

iTrader: (13)

Best I could do was tap hole 18mm ; couldn't get pipe plug that size so cut down a 18mm bolt , slotted end to use screwdriver and put it in with permanent sealant,
No probs so far

85mcss

iTrader: (5)

would it be frowned upon to plug the existing fpr's outlet as a temporary fix? Anyone tried that?

85mcss

iTrader: (5)

Also, is there anyone running the kirban or accufab thats over 600hp?

I feel like I am working on an old dinosaur now... the Stealthram.com site has been shut down... UGH!

vetteoz

iTrader: (13)

But there are ways

http://web.archive.org/web/200710210...com/index.html

Most of the links work