EFI fuel lines - are the stock ones big enough?

[AE71 Rolla]

I ran stock lines in my AE71 when i had the 4AGTE on 14psi of boost, running a bosch 040 fuel pump (400hp rated) and i had no trouble what so ever with not getting enough fuel. in fact it was overfuelling like a bitch

[Gilly]

i find this to be a bit of a personal opinion thing. i've heard of people successfully using the stock lines to feed 4AGE/ZE/TE's. personally i use the size lines the engine in question used originally, as Matty said that is 8mm feed and 6mm return. As Jase said use the original steel feed line as the new EFI return and run a new 8mm steel or rubber (EFI Rated) hose as a feed. i use rubber hose but it really isn't the best solution as it can be easily damaged causing leaks etc, my cars have all been engineered using rubber hose, but i may look to steel lines for longevity this time.

to answer the original question IN MY OPINION, no the stock steel lines are not big enough. if you've spent the cash to build up a 4AGTE spend the extra bucks to get your fuel lines up to standard. the rest of the fuel system sounds ok, i would personally run an intank pump to fill the surge tank then just the one external pump feeding the engine, that would be enough for your 150-160KW ATW's mark

[hillclimb86]

i re did my feeder line a while ago used bundy tube from tweakit used about 4.5 metres but that allowed for a mistake had to start again and used braided line and clamps to join to pumps and surge tank i just took the whole brake and fuel lines from under car took out old return and shaped bundy tube took a while fiddlely too worth it though peace of mind

[balistic]

Hey guys, just continuing on from this, I dug up some 10mm hard line tube out of the garage which I had stashed from an old project. I know 8mm was recommended but does anyone see any problems using 10mm for the fuel feed and the old skinny feed line as the fuel return? Will having such a size diff between the feed and return line cause a problem, (ie will too much restriction in the return cause fuel pressure stability issues)?

[PuGZoR]

What I'm doing is using 3/8" braided stuff as a feed (250PSI rated so it's sweet for EFI, for a 25ft silver length from Rocket Industries it's like $70 delivered I think), but I'm actually taking out the stock return line and putting it in there, meaning my new return line will be the larger 6mm ex-feed line. The braided stuff is a lot easier to work with if you want to follow the stock lines, in my opinion anyway.

[juzzo84]

i was running an ae71 on totally standard fuel lines, with a 20v turbo, running 1jzgte injectors and was making 125rwkw without a fuel problem at all. All i did was run a low pressure pump into a surge tank and then a high pressure camira pump up to the fuel rail. NO DRAMA'S whatso ever!!!
juzzo

[Joel-AE86]

I know 2 people who i'm fairly certain run standard ADM fuel lines in their 4AGTE's and both make around 150rwkw with no hassles.

I used to run my surge tank in my engine bay and had a lower pressure supply pump feeding through the stock lines into the surge tank, and then a high pressure pump from the surge tank into the fuel rail. In my new setup i'll be mounting the surge tank in the boot and running my high pressure pump into the stock fuel lines then into the fuel rail. Dunno if this setup will have any issues?

[balistic]

I'm thinking I could get by with the OEM lines, but decided whilst I have the car stripped down to a rolling shell I may as well do it properly and re-route a larger fuel feed. I'm going for a bit of overkill on the fuel system(being a track car) with twin Bosch motorsport fuel pumps from a 1.5litre surge tank.(had this stuff sitting around in the garage, so may as well use it!)



I havent looked into the tank yet, I'm assuming there is some kind of OEM lift pump inside the tank? Any suggestions on a cheap upgrade for this to feed the surge tank?

[PuGZoR]

If it's an ADM hachi, then no, you'll need to get a lifter pump. A lot of guys are using Carter pumps I think, but I just got some 100L/hr thing from Ripco. Cost me like $130 or something, I think, just low pressure piece of shit to supply the surgie. Should be sweet.