Hey guys i have a rx7 FC s4 and i am looking at running dual fuel lines but with the standard fuel rails.
Is this possible and anyone got any pics on this?
I have twin 044 pumps and surge but run standard fuel line from the pumps.
Cheers guys

 

If it's an s4 the rails are threaded. Here is one arrangement

 

hey mate thanks for the reply,
Yeah i am pretty sure its a s4 rails as the car is a s4 but i did change the manifold so not sure if it is s5 rail or not what is the difference?
Only thing is i will be running dual fuel lines to the rails so one rail per pump not just a splitter before.
I have a aeromotive reg on the rturn all ready and dual 044's and a walbro intake fittted

 

thus an s5 rail is not threaded on the ends (everything is basically one piece), so you can't install adapters like you can on the s4

 

don't forget you'll need two pulsation dampeners with this set up. if your secondary injectors are 1600cc or bigger you'll probably even need three.

A local builder here used that image and ended up blowing up his motor under "mild" conditions. IIRC he changed with FPR to a true dual and added a 3rd dampener and is still using that setup to this day.

 

and so are people NOT using pulsation dampeners.

 

so if i run two fuel lines, one line per rail then i have to run dampners?
at the moment i just run a fpr

what do the dampners do ???

 

fuel pulsation dampeners do exactly as they say.

when a larger injector opens up it lets fuel out from inside the rail. this creates a small low-pressure wave that ripples outward as the fuel rushes to fill the the empty space above the injector. if this low-pressure wave is above the other injector when it opens, less fuel is forced out of the injector causing a lean condition. the larger the injector the larger the pressure wave thus the need for another dampener.

pulsations are also caused by the fuel pump and small moments of fuel pump starvation. so yes you need a minimum of 1 FPD,

currently my set up feeds the secondary rail (the larger injectors) first and there is a FPD on both ends end.

 

I would love to see some actual proof of it, beyond "Look what happens when you shut water taps on old pipes" I haven't seen any of those running 8 1600cc's on aftermarket throttlebodies use them, and strangely enough they don't seem blow up for no other reason but harmonics in the fuel rails. Correlation is not necessarily causation...

 

that local builder who lost his motor to while using only one FPD found a 16page report on fuel system harmonics from the Chief engineer/mechanic at GM. what i so briefly summarized is what the what the engineer said but he went into a lot more detail on it and about the the many other related issues that also effect fuel delivery.
at a time i ran with no FPD and i didn't loose a motor but i was never able to get the HP out of it that similar builds had done. when i upgraded to the turbo i have now i used only one FPD and never blew up a motor but when it's so easy to have one or two FPDs it doesn't hurt to be safe/overkill.

 

Banzai Racing contacted Aeromotive a long time ago and they claimed that their regulator does a sufficient job that a separate dampener is unnecessary.

My natural reaction to this is skepticism, but there really isn't much anecdotal evidence of problems due to a PD elimination + external regulator setup.

See this post:

https://www.rx7club.com/showpost.php...8&postcount=14