Dual Feed Fuel Rail
 

I was wondering how many of you guys are running a dual feed rail? At what level of boost does it become necessary?
FYI, I'm at 7.5 pounds with my 1.6 injectors. If the clutch holds, I'll turn boost up a little when I get bigger injectors.

Edit: Did you notice a difference in egt after installation of the dual feed?

Thanks

The fuel rail is benificial to all cars as it distributes the fuel more evenly, to all the injectors. Unless you are going to run very high fp and huge injectors i wouldn't worry about it.

I agree. I doubt the factory fuel rail is doing much harm on a 1.6 at 7 psi. But having balanced flow is good insurance if you have the time to play around. Many people drill/tap the end of the factory fuel rail for 1/8NPT and put a barb fitting in there to make it dual feed. If you like bling and being broke you could buy a Vishnu rail. Jim B sells/sold an aluminum rail that should be better than stock too, but looked too crude for me, so I decided to made my own for shitsngiggles. :bigtu:

http://www.shoremotorsports.com/pics.../FuelRail2.jpg

Tim that looks really nice. It would look even nicer under my hood. :)

As for the original question, I agree that balanced flow to all injectors will never hurt. If you have the time and/or $$$, it'll give you an extra measure of safety.

I can't find it, but there was an old thread on another forum where Shiv (maker of the Vishnu rail) said something to the effect that stock injectors will never outflow the stock rail b/c their size so you're probably okay with the stock rail and 1.6 injectors. Bigger injectors and more power is another story as already said.

Are you guys serious?????

The DIY dual feed mod is so cheap to do and so easy.....why wouldnt you do it...
Ive done it on my car and it didnt take very long to do and is cheap insurance for your motor........DO IT!!!!

My only concern with modifying the stock rail is it failing. At over 100psi of fuel pressure it sure would suck having high pressure fuel spraying all over the engine. I guess if you are careful it shouldn't be a problem, but I'm paranoid like that.

use JB weld as a thread sealant

I haven't checked the pressures, but from what I understand the Pierburg can supply over 140psi of fuel when clamped off. My JB Welded fitting held the pressure fine, I'm not too worried about it since I'll only be pushing 108psi or so.

Regular fuel injection hose (SAE30R9) is required to have higher working pressure rating (125psi) and minimum burst pressure rating (900psi). If you are worried about pressures in your fuel lines then, look for an SAE rating on the hose. SAE30R6 and SAE30R7 are low pressure hose for carburated enginges (rated for 50 psi and a minimum burst pressure of 250 psi) and SAE30R9 is a higher pressure fuel injection hose. If your hose has a number between R7 and R9 it is a medium pressure hose.

From what I've spoken to with Corky the same thing applies to the rail itself. He's much more conserned with the FPR failing before the lines and hoses fail.

It's not that the fuel pressure would cause a failure, but sure would suck if it ever did fail at over 100psi.

Having said that ... what sized fitting are you guys using? :)

1/8" to 5/16

That's 1/8 NPT to 5/16" barb, I believe.

yeah, too many extra letters to type.

I run a DIY dual feed (OEM tapped at one end). No idea when you need it but I am running 12-13 psi right now on 440 injectors.

Exactly. I'm quite confident in my abilities, but if it ain't broke then there's nothing to fix... I'd rather invest limited resources (and time IS a resource) into meaningful mods. If it's not necessary at 8 psi and 230cc injectors, then there's no use. OTOH, if it keeps the temp at #4 down, then it would be worthwhile.

I think it's safe at any level since it will balance out your flow through the rail. Who needs a #4 failure!?!

Thanks for your answers guys. Did anyone notice any change in egt after this mod?

Thanks

I know several people who have lost #4 @ 8psi. Why risk it?

Loosing #3 and #4 cylinders probably has more to do with poor water circulation than the fuel rail.

This post made me do a lot more reading up on dual feed fuel rails and learned two interesting things from some old threads about people who did some actual dyno testing.

#1 dual feed stock rail (~$10) was just about as good as vishnu/FM/****'s for most applications on the dyno. Granted, the more radical the setup, the higher end stuff started to make some gains over the stock mod.

#2 More than just for safety, most people on the dyno were able to advance their timing a few degrees b/c of the dual feed rail and hence make more power. Interesting....

Someone should post a "How to make a double feed fuel rail." I looked but didn't find anything (with pics), if someone has one with photos then post it if you could.