What fuel lines with EFI fuel tank.
 

I have a 78 trans am with a fitech efi setup W fuel command center under the hood. The pump just died for the 2nd time so i have decided to put a new efi fuel tank in it. Can i use the existing steel lines or should i be running all new braided fuel lines and get rid of all the steel lines. My steel lines are in good shape and if i dont need all new lines it will save me a few bucks. I dont want to shortcut anything either. I haven’t seen a lot of plumbing info for EFI setups on the TA’s. Thanks for any advice.

More than likely the steel lines that you currently have are not large enough (specifically the return line) to flow the necessary amount of fuel required by the setup.

You will need at minimum a 3/8" supply and return line. Most of the return lines from the factory on these cars are actually more of a vapor return that is not designed to pass much actual fluid. Most of the time they are 5/16" and may crimp down smaller in certain places. It's not adequate for returning lots of fuel back to the pump. The net result is that the return line starts to build pressure in the line, which then increases fuel rail pressure as the pressure regulator is unable to cope, then you get an oscillating rich/lean condition that causes surging and stalling of the engine.

For long term use without the need to replace lines, going to a properly sized stainless steel hard line is preferred. That said, if the car is not used often, is not driven or stored in lots of inclement weather etc. you can certainly do EFI rated soft line.

This kit is cost effective, contains quality parts and is everything you need for the fuel system. https://www.tanksinc.com/index.cfm/p...rod/prd548.htm

I have been running that kit on my wife's chevelle now for several years and my Firebird has a piece meal kit of the same type that has been in-service without issue since 2015. Just know that a soft line system will not last as long ultimately as a proper stainless steel hard line system.

Great info thank you i had no idea about the return line causing issues. Will this fuel line pass tech inspection if i want to make a run down the 1/8th mile. The car has never been on the track but we have one opening up in town so i my have to see what the car will do.

It's crazy to use hose where metal or OEM-style hard-plastic tubing will suffice. Tubing has a longer service live, costs less, weighs less, and is less permeable than rubber hose. It costs MUCH less than Teflon/PTFE liner hose.

"Hose" should be kept to a minimum--only where needed to allow for engine shake, or to make connections to other components.

My car is teched to 11.50 with the pressure rated hose. This tech was done at Bandimere Speedway, which is an NHRA track. They don't necessarily have a reputation of being stringent with the rules, but also not over lax with them either.

That's a hard question to answer. If one were to go by the book to answer that question it would have to be no. I haven't seen a recent addition of the NHRA rule book but if memory serves me, they don't like to see more than about 12 inches of rubber fuel line throughout the car.

That said, in most cases going through tech they probably don't care much on a typical 12 or 13 second street car rolling in and likely won't scrutinize a car like that too much. They'll just check a few basics, then limit you to 11.50 if you don't have a roll bar. Some of the faster cars they might take a closer look at. Just depends on the track and what kind of mood they are in.

I've been through tech where they checked lug nuts, battery, overflow bottle, opened up the trunk and the spare tire wells looking for nitrous, even had me put the car in gear and try to start it making sure I had a working neutral safety switch, lol. Then other times they don't even ask to open the hood. Just never know but I will say one thing, It's never been consistent.

I used Inline Tube 1/2" stainless steel supply and 3/8 return. They are already pre bent and fit right where the original line was. I'm using a Tanks Inc. tank with a Walbro fuel pump and an FITech 1200 Power Adder (which I am about to sell), the point is I have a similar set up as what you are about to do.

& the 3/8 return works ok? i always hear the return has to be the same size as the feed line. going pre bent metal lines seems to be the better way & if a 3/8 return is ok that makes it even easier.

It depends on how far you are regulating it down, how big the pump is that is required to feed the HP you have etc...

If you are running a simple 500hp setup with a carb, and regulating it down to 6-7 psi, you can run a typical 255 LPH pump. In which case you can probably get away with a 3/8 return line. I still generally run a 1/2" return anyway because the cost is the same, and it leaves room to grow later. I tend to like running a bigger pump than required anyway to give some wiggle room that the formulas don't take into account like friction and G forces that affect fuel delivery. Plus most of the pump ratings are free flow anyway.

I agree with a lot of what Jones is saying. But be careful, I put in a Walbro 340 LPH pump and that friggin' thing puts out 90 PSI of pressure dead headed. Lol

I used a combination of 3/8 Copper nickel tubing and Earls Vaporguard hose.

https://www.amazon.com/Brake-Line-Co...0482360&sr=8-3

I've never seen copper tubing used on a vehicle before. Why did you choose copper?

It’s called NiCop, I believe. Most all the parts stores keep it. Very easy to work with. That’s it’s main advantage.

Murf


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Ok. News to me. Advantage vs. AL, SS, or carbon steel? Copper would look kinda weird to me.

I ran 1/2" od AL supply and return lines many years ago. I'm converting to LS engine now. I am thinking about changing it out to SS. Anyone have pics of Inline Tube or other brand pre-made lines installed?

Copper Lines would not be allowed on any SCCA type Race car at a club event.

Too soft and too easy to be damaged and a potential fire from the rupture of the line.

Tom V.

That makes sense. This copper fuel line thing has me scratching my head. Engineering choice of materials 101.

Here's a picture of the 1/2" stainless lines I did on a 2nd gen Firebird. They simply run along the factory route so not much to see, even come with the spring wire wrap like factory. Most people looking at it wouldn't even notice it's 1/2" line.

The NiCopp or Cunifer brand tubing isn't pure copper, it's a nickel-copper alloy. It's relatively new in the US but has been used for years in Europe for brake lines as well as fuel lines, so it has the ability to handle high pressure. The big advantages over steel are it won't rust, and it's easy to bend and flare. It is DOT approved, if you're going racing I suspect it's probably OK but check with your sanctioning body.

edit: when I say 'relatively' new, it has been available in the US for probably 20 years now; it's just that it's been in use in Europe a lot longer than that. I believe it's OEM on Porsches as well as some other makes, so it's most likely OK for competition use.

I’m using nicopp for fuel and brake lines on my Firebird pro-touring project…mostly because I want to bend and flare all the lines myself. I practiced with other materials and found nicopp to be the easiest to work with.

If I saw it approved in a recent SCCA manual, I would change/amend my post above.

Tom V.

This is from some years ago. 4/10/2011

https://forums.maxperformanceinc.com...d.php?t=662999

Quoted from Post #5

"

DOT APPROVED
FOR BRAKE AND GENERAL
AUTOMOTIVE APPLICATIONS

NiCopp® is a nickel-copper alloy brake tubing that meets SAE Standard J1047 and ISO 4038, meeting all international and U.S. requirements for brake tubing. This alloy is approximately 9.2% nickel, 1.4% iron, 0.8% manganese, and 88.6% copper. Under the UNS system, this alloy is designated as UNS C70600. NiCopp® therefore has the strength and structural integrity of steel lines, but with the added benefit of being much more corrosion resistant. NiCopp® is also easier to bend and form than steel tubing. Nickel-copper, commonly referred to as '90-10 copper', has been used on several European vehicle brake systems since the 1970's, including: Volvo, Audi, Porsche, and Aston Martin.

NiCopp® has been used on hydraulic/fluid transfer systems on vehicles where steel lines and tubing are commonly used. This includes brake, fuel and transmission systems. NiCopp® is considered the super-premium brand in brake lines and should be considered where the underbody of the vehicle is subjected to the harshest environments, where the longest life-span for lines is required, and/or where direct OEM replacement is desired.

* • NiCopp® Does Not Rust or Corrode
• DOT Approved for Hydraulic Brake Systems
• Bends 58% Easier than Steel Tubing
• Available in Coils of 25' and 100'
• Finished Lines Available for Domestic & Import
• Black Oxide Fittings 2X Corrosion Resistance

NiCopp® lines and tubing meet the following specifications:
SAEJ1047
ISO 4038
SAEJ1650
DIN 74234
BS2871

Tom Vaught

ps If it will pass the "Gorilla Stomp" test by the Scrutineer/Inspector from the SCCA you are good to go. Have seen many "copper brake lines" fail that test. NiCopp MAY pass that test. "

"Gorilla Stomp" test is both feet on the brake pedal (as in a panic stop with lots of force to the pedal and lines generated). Street driving and never in a panic stop might last for years and years.
Would you want your wife and kids in the car if you had to do a panic stop and the line failed?????

One other option might be one of Holley's in-tank pump /regulator combos. Here's the listing for your Firebird: https://www.holley.com/products/fuel...s/parts/12-304

The neat thing is that you retain your stock tank. The pump and regulator are mounted on the pickup, so there is no return plumbing to worry about. The regulator is pre-set to 58psi. So all you need is the stock steel fuel line forward, but remember to replace any rubber line with EFI rated hose and clamps. On the FiTech throttle body, cap off the return port and the possibly the vacuum port to the built-in regulator. Something to think about anyway.

fwiw, I did this "dead head" style setup previously on my '38 Chevy street rod FiTech setup. But as these new Holley products weren't available at that time, I used an in-tank pump with an LS-style Corvette fuel filter/regulator unit instead which shortened the return as much as possible. I wish something like this was available back then.

That's happened to me a few times. I just play dumb.


I don't know why's it's not working sir, I promise I'll get it fixed before next time. lol

Perfect! Thanks! It looks better than my AL lines for sure. Where do they route/stop up front?

They run along the factory route up the passenger side frame. For this particular year (72) they run on top of the frame by the control arm and then terminate where the short section of a 3rd set of lines would have been that run across the front of the engine cross member over to the fuel pump under the front of the oil pan.

On a 70 model like mine they make a turn behind the engine cross member and run under the rear of the oil pan and then over the cross member to the fuel pump.

Here's a picture of the front section of the 1/2" lines in the factory location (for 72) That lone bolt next to the cross bar of the upper control arm is where another line clip goes, which will hold the lines closer to the control arm where they should be. I just didn't have it installed yet for this picture.

thats one thing i dint like about the earlier 70-73 cars is the passenger side fuel line & the line going across the front of the oil pan... the later years & the OP's 78 are a much better design, routing on the driver side & not crossing over the cross member or oil pan.

I actually like this design on the 72 where it crosses in the front under the oil pan. It gets plenty of air flow up there and basically comes along the side frame rail where it isn't all that close to the engine.

I don't like my 70 though, it's a little different. It crosses behind the cross member under the engine between the cross member and oil pan sump, then runs up and over the cross member along the oil pan rail to the fuel pump so it's packed with a lot of heat and doesn't get nearly as much air flow as the front version.

Depends on what you are going to do. For me, running the line up the passenger side of the car and engine ended up with a cleaner install. I had an almost a straight shot from the rear frame rail where I have the LS regulator installed, along the SFC to the front frame rail and up into the engine compartment along the upper control arm mount and terminating after clearing the control arm. I had to put two 45 degree bends in the entire line.

i suppose theres pros & cons to both ways depending on what youre doing. i just like the 78 routing on the driver side for stock mech pumps better since the line doesnt need to make a right angle turn all the way across the front of the engine to reach the pump like on 72's... even with air flow the line is actually clamped to & touching the oil pan which transfers a lot of heat in stop & go driving or sitting in the staging lanes at the track.

where it runs on top the frame next to the engine its very close to the headers if you have bigger pipes, my line is all of about 2" from the big 2" tube super comps i run, way to close for comfort, i had to use some heat wrap on the line in that area its so close. you can kid of see it in this pic, runs very close, would be much cleaner & away from major heat sources on the driver side. they make the later year driver side run in 1/2" too & would be much easier than trying to convert a later year car to passenger side routing.

That doesn't look too bad for clearance. I think even with the RA manifolds on the 72 I did it was still just a couple inches. I'm okay with that. As long as I can get a hand between fuel lines and heat sources I've never had an issue, and being where it is with plenty of air flow tends to mitigate any would be issues.

On my 70 the factory didn't come up and over the frame rail like that. It's all hidden behind the engine cross member and runs under the oil pan sump. What's worse is it makes a turn to come up and over the cross member on the driver side, still running under the engine between the block and the RA exhaust manifold where there is a ton of heat and very little air flow. I've just never like fuel lines running "under" engines like that.

I'd much rather have that come up the top of the frame rail by the upper control arm. It seems to be the lesser of 2 evils I think. Honestly though I don't think there is a real good way to do it on these 2nd gens.

Coming up the passenger side is fine, but I'd like that better if the car didn't have power steering, and the front mounted steering box. Which I think is why initially on the 70 models like mine when they crossed under the back of the engine, they didn't come up and over the top of the frame there, and ran it under the engine along the block instead. Of course the starter is there too.
baaaaa lol Always something

that pic is kinda deceiving since the close area is hidden by the A-arm mount part of the frame. the heat wrap does its job & ive never had any type of vapor lock or hot fuel issues, just closer than id prefer.

He said Copper-Nickel. Not copper. Big difference. OEMs use it

I cannot overstate how much I love working with copper-nickle tubing. Makes plumbing a car so much easier.

I don't have a problem plumbing regular steel lines. Easy enough to work with :noidea: