Firechaser

Love the dual-fed rails...same setup I made for the GN...every cylinder gets fed now!

Exotic-metal55

I posted a few years back about our very small fuel rail inlet issue. This was the same time I posted how we needed larger injectors above 520 hp, injector info and how our fuel pressure goes from 80 psi to 62ish psi above 4500 rpm. I drilled my inlet from 5mm to 6mm at that time but that was just slight help.

This duel line and Y inlet set up ,has been used on performance cars for a while and is really nothing new. Just new for our cars and another option I wanted to share, if you need a more stable fuel supply. I have the stock in tank fuel pump , that feeds a bosch 044 inline pump and I used 8an main line to my Y fitting. I am also using 715cc Injector dynamics injectors , as the 550CC will start to get near max duty cycle at 600 hp. Also needed the larger injectors to run the E85 , as you need about 28% more fuel. Going to E85 last year and just changing to 715cc injectors, I was pretty much dead on with my AFR. There are online calculators for fuel flow and how much HP you can make per line size and 5mm sucks for making a lot of power.

chawkins2001

How does your car idle with the 715CC squirtters, is there any idle hunt there?

Mine hunts slightly, but I am on 1000cc slugs, and I have a different line and pump setup than yours for my E85.

GT-ER

My car has 750's and my tach doesn't budge at idle, I do kind of feel a slight vibration in my steering wheel that oscilates which could maybe be due to the injectors, or due to my wobbling pulley...who knows...lol

Exotic-metal55

Have not started this new engine yet but last year the idle was very smooth with the 715cc Injector dynamics. Like ID says, "the 725 injector exsist for the application, where rthe 1000 Id is a littel to big"

Check out the flow, engineering data and you can see how these injectors have reached near cult status, as they say.

http://www.injectordynamics.com/ID725.html#Dynamic Flow Characteristics - 4.14 Bar (60 psi)

IMO, we can run all the loops, big pumps and larger injectors we want but if you leave this 5mm ID fuel inlet,,, all that other work and flow is no help. Even the stock line is only 6mm ID, so limited again but helped by our high fuel pressure some. I had a picture showing this but cant find it at the moment.


GT-ER , may I ask what brand injector you are using?

If any of you decide to assemble the bottom end of one of these engines, the bearings are color coded and can use specific color/sizes for each jouranl. Nissan has done the same thing with thier engines and it is tricky to getting this right. Even if you take apart the botom end to clean and inspect, bearings need to go back where they came from. Color codes are marked on the crank and also on the block next to each journal, where the oil pan seals.

GT-ER

I got my injectors from EC but they arent the ones on the website. I think they are the same red 750's that Five-O Motorsport sells.

benzmodz

To save more weight install some helium in the cabin ... then phone me.