Yet another fuel system question....

I have seen aftermarket fuel rails set up both ways. Is there any advantage to running the rails in parallel vs in series?

Parallel needs more parts...I'd have to take the feed line and run a Y, then two 180* bends into the front of the rails, then out the back and run two lines into the FPR, then out from the FPR to the return line.

Series I could just run the feed line into the back of one rail, from the front of that one to the front of the other one, then from the back of that one into the FPR, then straight back to the return line. Seems much simpler this way.

Any reason to do one over the other?

 

I would think you would get a more even distribution of a fuel pressure if you did them in parallel instead of series. Whether or not the variation in fuel pressure makes enough of a difference I am unsure about

 

i would say you could get better fuel distribution in parallel...but then again it is just alot more parts!

Dustin

 

In your situation I would run them in parellel... There will be a pressure and volume drop inbetween each injector, so the first and the last injector will have different pressures. How much and is it significate, I dunno... Easiest way to describe it is to put 8 sprinklers in series on a garden hose. The first sprinkler will put out alot more volume than the last at a given pressure... Now repeat that same thing but in parellel, 4 on each side. The volume is much more consistant. You would really have to do some calculations, mainly using Bernouly's equation to measure the pressure drop inbetween each point... But a law of thermo/fluid dynamics states that a pressure drop will occur at each orfice (each injector), at each bend (the 90*s), over the distance the fluid travels, the differences in friction inbetween the rails and cross-over hoses, and the differences in sizes of the rails vs the cross-over hoses........

I took a few thermodynamics and hydrology courses in college (Physics minor)... I am a little rusty thou...

 

My boosted vette has aftermarket rails and is run in parallel

Here's a picture that should give you some plumbing ideas.



It has a stock intank and a -8 sump fitting in the tank into a 255 lph external pump, y'd together in the back, holds 60 psi no problem against 20 pounds of boost. what you can't see off of the Y is another -6 that runs to the back of the passenger side rail into a 135 fitting. In a C5 you can't go into the back of the driver's side rail clearance wise, truck shouldn't be a problem.

 

Thats a nice looking vette!

Dustin

 

yeah, just a lil bit of forced induction there with stock cubes, ls6 heads, and intake. Great example of how you don't exactly need big dollars in a longblock to make stupid power via boost, well if you have the cojones to run 20 pounds on pump gas with meth.

 

So what vehicles do you own that don't have boost???

 

um, the ones with juice?

the road race vette, the old tahoe had boost but doesn't anymore. my 96 roadmaster station wagon is stock, my 96 caddy fleetwood hearse is stock, my 55 belair doesn't have boost, but I have a boost motor sitting in teh garage for it. my bike doesn't..

but boost is just addicting, don't you think?

 

Apparently, unfortunately some can not afford it yet