Trying to go return system - please help

[1Kona_Venom]

Anything over 800 I recommend aftermarket rails. And not for HP or increased flow, but for supply volume. How much do some of you have in your car setups? You don't want to spend another few hundred bucks for piece of mind? Sounds pretty dumb to me. Hey, let me go spend 3k or 4k on a nice TS, but I am not going to spend less than 10% of that on rails.

^ this. trolling (<--me) on this thread, I initially was going to run the bap with just 80's on my 2.9 (as per my tuner) but now Im seriously considering going with MORE IS BETTER......now if I can just configure a ball park price w/o calling Lethal on a Black Friday:lol::nonono:

OP, ty again though, for asking about this :beer:

 

[MalcolmV8]

I am not questioning that the rails will or will not support big power. Instead I am saying that in a return setup, it cannot maintain the flow needed for big power.

In a return setup the regulator is trying to maintain pressure. But the fuel is deadheading in the rail.

Here is a link where I tried it. Fuel press kept falling off bad.
building a return fuel system!

Thanks for that link. I read the whole thing (all 8 pages). It had some great pictures too. I saw you setup EXACTLY what my idea was with the stock fuel rail. It didn't look like you ever tried it out? It seemed like you just got a lot of flack from the guys on the forum there and changed out your rails. Did you actually run it?

Thank you too for your pictures of how you did the return system with the new rails. It's one of the cleanest setups I've seen. The black hose (is that fragola?) and the black fittings on the end made it look like it belonged. The 180 bend you used on the driver's side is a nice touch that I had in mind.
On the passenger's side you used a 45 it looked like and went into the fender well in the front of the motor. Nice touch there too. I noticed some yellow plastic on that fitting? I assume that was unavoidable.

One thing that completely contradicts your theory of dead ending the fuel in the fuel rails on a return system is Jared's setup (Lethal's cars). If you go back to the first page of this thread and read his post again he says he has the fuel come into the FRPR and then go into Y blocks and into ONE end of the fuel rail and has the back end of them capped. He has that on his GT500 and his 03 Cobra and we know he runs big numbers in both cars. Do you think his success at it where yours failed is just because he's using the large rails?

 

[Robertp]

The drawn out picture above (the last one) is the best regulator after the second rail, this way u know all injecters are getting full pressure

 

[sn94cobra]

Thanks for that link. I read the whole thing (all 8 pages). It had some great pictures too. I saw you setup EXACTLY what my idea was with the stock fuel rail. It didn't look like you ever tried it out? It seemed like you just got a lot of flack from the guys on the forum there and changed out your rails. Did you actually run it?

Thank you too for your pictures of how you did the return system with the new rails. It's one of the cleanest setups I've seen. The black hose (is that fragola?) and the black fittings on the end made it look like it belonged. The 180 bend you used on the driver's side is a nice touch that I had in mind.
On the passenger's side you used a 45 it looked like and went into the fender well in the front of the motor. Nice touch there too. I noticed some yellow plastic on that fitting? I assume that was unavoidable.

One thing that completely contradicts your theory of dead ending the fuel in the fuel rails on a return system is Jared's setup (Lethal's cars). If you go back to the first page of this thread and read his post again he says he has the fuel come into the FRPR and then go into Y blocks and into ONE end of the fuel rail and has the back end of them capped. He has that on his GT500 and his 03 Cobra and we know he runs big numbers in both cars. Do you think his success at it where yours failed is just because he's using the large rails?

I did run the setup with stock rails. It would not hold pressure.

I tried to make my return setup as clean as possible.
The yellow ends cam with the fittings. I don't like the yellow to be honest. But I didn't want to remove them.

As for the dead heading. The returnless system works by deadheading the fuel, but the pumps have to ramp up hard to maintain that pressure. Hence why you see the FRPS at the end the rail furthest from the inlet to the rail.
The computer reads the FRPS and helps ramp up the pumps (at least this is what i believe to be true)

With a return setup, it is my belief ( I am by no means an expert) that the when the computer reads the FRPS it cannot compensate by increasing pulse width to the pumps because they are constant. Nor can it increase fuel pressure at the regulator. In a return setup the computer reads the FRPS and increase injector duty cycle.
By using aftermarker rails and having the regulator after the rails, you can maintain volumn and pressure at the injector.

I was like you, the thought of spending that much money on rails, regulator, lines and etc was expensive. But so is rebuilding a motor because you skimp on fuel.

My new theory is go overkill on the fuel. with my setup I still need to work on this.

Hope this helps.

 

[sn94cobra]

also keep in mind I am running E85. That may be why my setup didn't work. Because of the volumn it requires.

 

[MalcolmV8]

OK after many hours in the garage mocking things up with what parts I have I've narrowed it down to two designs. I have the front passenger's wheel off and plastic fender well liner off and and going over many layouts these are my final two designs I've come down to that I can do.

This first one will be a much cleaner setup but I have to think I'm limiting the HP it will support by daisy chaining the fuel rails. I have no evidence to back that up other than just logic in my head for what that's worth lol.

Here is a design that will be a lot harder to pull off with such tight space to work with but I think it's doable. The Y block will be in the passenger's fender well and the FRPR will be in the engine bay right up by the passenger's side fender well. I theorize that this setup will support more HP than my design above.

 

[sn94cobra]

The first one is how I have mine. If i can get my pumps lined out, it will support plenty of power that way. Mine is currently supporting 675-700 rwhp on E85.

 

[MalcolmV8]

The first one is how I have mine. If i can get my pumps lined out, it will support plenty of power that way. Mine is currently supporting 675-700 rwhp on E85.

That's pretty stout. I'm sure it can handle a lot more too. When you look at -10 or -8 line versus the stock stuff and those Fore/DX rails compare to stock there's just such a ton more fuel flow happening.

What does it mean "If I can get my pumps lined out"?

 

[cbr repsol]

how are u getting a single feed starting from the hat? A return hat has 4 ports, return line port and 3 feed ports.(Unless somethings changed) So running twin 400s u need to block one with a plug and run both feed into the yblock within the first 5-6 feet or so. Then running the -10 to fuel filter then to fuel pressure regulator. I didnt see any fuel pressure regulator in your drawings, if u dont put one in u hill have a Shi* ton of pressure.

 

[sn94cobra]

That's pretty stout. I'm sure it can handle a lot more too. When you look at -10 or -8 line versus the stock stuff and those Fore/DX rails compare to stock there's just such a ton more fuel flow happening.

What does it mean "If I can get my pumps lined out"?

I still am having a little fuel pressure drop at the top of the rpm. This is even with a BAP and 60 psi base pressure. I think I either have some week pumps or a line leaking inside the hat connecting to the pumps.

I never witnessed fuel pressure drop on race gas. just with the E85.

This was a 708 rwhp pull. So the pumps must not be too bad :rockon:
http://www.youtube.com/user/wldtang?feature=mhee

 

[MalcolmV8]

how are u getting a single feed starting from the hat? A return hat has 4 ports, return line port and 3 feed ports.(Unless somethings changed) So running twin 400s u need to block one with a plug and run both feed into the yblock within the first 5-6 feet or so. Then running the -10 to fuel filter then to fuel pressure regulator. I didnt see any fuel pressure regulator in your drawings, if u dont put one in u hill have a Shi* ton of pressure.

You're thinking of the old triple pump hats. They don't make those anymore.
The current hat(s) made by DX and Fore only have two connections. Feed and return. Both are also only dual pumps now days.

Even my old dual pump Fore hat currently in the car only has a single feed. It has a Y block built into it... so to speak.

As for fuel pressure regulator in my pictures it's the item labeled FRPR (fuel rail pressure regulator).

 

[MalcolmV8]

I still am having a little fuel pressure drop at the top of the rpm. This is even with a BAP and 60 psi base pressure. I think I either have some week pumps or a line leaking inside the hat connecting to the pumps.

I never witnessed fuel pressure drop on race gas. just with the E85.

This was a 708 rwhp pull. So the pumps must not be too bad :rockon:
wldtang's Channel - YouTube

I wonder if you're hitting the limit of one fuel rail feeding the other fuel rail? On E85 you're trying to feed some 40% more fuel. That's why I'm leaning towards the second pic I have that feeds each rail independently from the Y block.
Of course maybe you just need stronger pumps too. You have the GSS342 pumps don't you? (walbro 255 lph) or was it the or was it the DX stryker pumps at 340 lph? I forget now. Either way some DCSS-405 400 lph pumps may fix that.

Base pressure of 60 PSI is really high isn't it? Although I suppose it doesn't matter does it, it's just what ever your tune is designed to deal with.

Nice pull on the dyno man. Your car sounds wicked.

 

[cbr repsol]

u have to regulate the pressure before it goes into the rails. The way u have it ,its regulated before it goes back in the tank which does nothing.

 

[MalcolmV8]

u have to regulate the pressure before it goes into the rails. The way u have it ,its regulated before it goes back in the tank which does nothing.

You sure about that? I think you're wrong lol. I don't actually have one yet to read the instructions but from everything I've read on the net so far seems to indicate they have INPUT port(s) and a RETURN port. They do not have a regulated OUTPUT port.

The way I understand it working in my above pics is say the pumps are putting out enough fuel to be at 70 PSI, if blocked off, but I only want 50 PSI the regulators sit after the fuel rails and bleed off excess pressure via the return back to the tank. After all PSI can only build up if there's lack of flow. Open up a return path to bleed off excess fuel back to the tank and the PSI will drop. That's how it keeps your rails at X PSI.

I could be completely wrong in which case I have to go back to square one and start re-designing my layouts. I'm sure someone who's done a return system can tell us for sure how the fuel rail pressure regulator works for sure.

 

[TRBO VNM]

Can you elaborate on how it did not work for you? I'm not saying you're wrong, just trying to understand it. Especially when Kenne Bell says stock fuel rails support over 1000 wheel hp. It's not like KB is just some random idiot, they are a well respected company that's done a lot of testing. Have you seen this link?
http://kennebell.net/KBWebsite/Common/pdfs/DoINeedLargerFuelRails.pdf



I really don't mind spending the money on some fuel rails if they're needed. I'm just trying to justify it when I see a very reputable place like Kenne Bell prove with many tests that stock fuel rails are good to 1000 + wheel hp.
http://kennebell.net/KBWebsite/Common/pdfs/DoINeedLargerFuelRails.pdf

BTW, thanks again for the call this morning. Lots of good info I appreciate. Based on your explaination I believe this is the setup you normally go with

My other option of course is I could just leave everything alone and put a BAP on my GT pump setup for some $200 and get the same support for my 600 ~ 700 whp as an $1800 fuel system.

No problem. Like I said, give me a call if you have any other questions.

But why are you posting the same link twice in your thread? And after it was posted in a previouv post oke:

I did read it and really, they have their opinion and I have mine. Working on these cars long enough and others, I have certain criteria I stick by and recommendations to others. Fuel is one thing I don't mess with and don't care to short change myself on or others. I provide the info and my thoughts on it and let others decide what they want to do. 9.9 times out of 10, I am the one that says I told you so.

how are u getting a single feed starting from the hat? A return hat has 4 ports, return line port and 3 feed ports.(Unless somethings changed) So running twin 400s u need to block one with a plug and run both feed into the yblock within the first 5-6 feet or so. Then running the -10 to fuel filter then to fuel pressure regulator. I didnt see any fuel pressure regulator in your drawings, if u dont put one in u hill have a Shi* ton of pressure.

As he stated, it is one outlet and inlet on the newer hats. Although, I think with triple pump hat, you still have three ports, but it is designed now with a return port built in so you don't have to weld a return fitting to the tank.

Fore had like 3-4 different designed hats and now them and Lethal/DivisionX have revised things so the hats have single ports for dual pumps.

And he has a regulator on the schematics. I forgot the letters he used, but typically it is FPR.

u have to regulate the pressure before it goes into the rails. The way u have it ,its regulated before it goes back in the tank which does nothing.

This is incorrect. There are many different ways to run the setup. I have mine as one of his diagrams...feed the rails from my y-block and then other end of rails goes to regulator and then back to the tank. You can feed the regulator and then feed the rails if you want, but you don't have to. Plenty of options.

Malcolm,

Mount the y-block under the car. Not in the wheel well. I put mine under the front floor board just in front of the seats(under the car of course). You can lift the carpet and drill a hole, use some RTV around the hole on the bottom between the block and floor board to help seal it and prevent water from getting there and rusting. That hole is to mount the y-block if you didn't catch that.

And man, you are making this difficult on yourself. LOL

 

[MalcolmV8]

Thanks Jason. More great advice and info I really appreciate. Do you put the Y block under the car instead of the passenger's fender well for clearance issues?

Don't mean to make it look hard on myself lol. I just really like to understand how everything works. My car is probably one of my favorite hobbies. The more I understand it the more I can make changes, enhance, modify etc.

Thanks again
Malcolm

 

[cbr repsol]

thanks for clarifying trbovnm.. i wasnt aware it would work that way. im used to feeding the regulator first. Is there any benefit to doing it the other way?

 

[MalcolmV8]

I wasn't aware you could feed the regulator first. If so I could feed the regulator and then feed one end of the rails and cap the other end and have a lot less work to do right? Much cleaner looking setup too.

 

[black03]

I wasn't aware you could feed the regulator first. If so I could feed the regulator and then feed one end of the rails and cap the other end and have a lot less work to do right? Much cleaner looking setup too.

That's how I run return setups on all of my cars as well as how we set up the complete return systems we sell.

Jared

 

[TRBO VNM]

Thanks Jason. More great advice and info I really appreciate. Do you put the Y block under the car instead of the passenger's fender well for clearance issues?

Don't mean to make it look hard on myself lol. I just really like to understand how everything works. My car is probably one of my favorite hobbies. The more I understand it the more I can make changes, enhance, modify etc.

Thanks again
Malcolm

Mainly clearance but also in case you need to do any maintenance for any reason it is easier to access.

And yup, why I help and like working on cars. I enjoy it. People think I am crazy for doing it as a second job, but I am always going, always haved something going on and really can't just sit there and do nothing. It is hard for me to enjoy vacations because I rarely ever can sit and do nothing.

thanks for clarifying trbovnm.. i wasnt aware it would work that way. im used to feeding the regulator first. Is there any benefit to doing it the other way?

Well, from what I have read and talking to people, the way I have it setup helps maintain the pressure better, but the possible downfall is the fuel has an opportunity to heat up. But really not enough to be a concern and affect things. IMO, I would not dead end a rail in a return style setup. Look at our #7 and 8 pistons and the coolant dead end in the head.

That is the trick with these larger blower. How to route everything so you have the best possible setup, but able to get it all installed.