Dual Entry Fuel Rail

[75coupe]

So I have a new sard fuel reg, fuel rail and dekka 840cc injectors for an E85 setup...

its a dual entry fuel rail, I can either run it as a stock setup and block the centre return, or run dual entry with the centre return going to the fuel reg.

but is it ok for my to use a Y splitter to supply either end of the fuel rail or do I need a two pump fuel setup to supply either...

Im thinking it will be fine using a splitter as surely either way wouldnt change fuel pressure at all but just thought I would check before I get all the lines made up and install it all...

I did a search but couldnt find this scenario

on a related topic, has anyone made up their own braided lines with speedflow fittings or do people usually get someone else to make up the lines?

how hard is it to do yourself?

any special tools required?

or do I just get someone experienced to make up the lines?

Any cheap good place to get fittings and line from?

[JonnoHR31]

Y piece should be fine. would be easier to just block the centre and run it like the standard setup tho, less lines and fittings that way

[75coupe]

what about tuning factor? any change in fuel delivery?

[XRATED]

With the amount of flow you will need for the E85 it's worth the few extra bucks to pop in a t piece or y piece and run the extra line to the front of the rail... It dosn't have to be a billet alloy- cnc machined- aerospace y piece... a plain steel or bronze T piece will do.

J.

[75coupe]

so split the line after the fuel filter obviously yeah?

what would the neatest why to arrange speedflow fittings and lines, anyone with ideas?

[Nee-san]

In high flow applications IE E85 + big horsepower using big injectors etc, it's pretty easy to see how there would be a substantially pressure drop over the length of the rail. especially since our engines are long (comparatively)

[75coupe]

so are you saying dual entry is good idea with E85 setups?

what fuel pressure do you think I should be chasing?

[Nee-san]

I will say that Dual Entry is Better.

Necessary, I can't say but I'm certainly doing it with mine, HKS rail, fed from both ends with the FPR in the centre mount point.

When I referenced E85 I did so because generally the flow required for this type of fuel is far greater then in petrol applications generally ~30% more.

think about it,

Fuel comes in one end at pressure, but is being drawn out by 6 Injectors one after the other, by the time the fuel reaches the other end, you can see how there would be a pressure drop.

As for what pressure you should run, talk to your tuner.

[mattis96]

i would get someone to put the fittings on the hose for you, i watched you tube videos on how to do it and looked piss easy, gave it a go and ended up screwing the thread on the fitting, but that was my first time trying it though, but thought much less frustrating to get someone else to do it

[DVS JEZ]

I will say that Dual Entry is Better.

Necessary, I can't say but I'm certainly doing it with mine, HKS rail, fed from both ends with the FPR in the centre mount point.

When I referenced E85 I did so because generally the flow required for this type of fuel is far greater then in petrol applications generally ~30% more.

think about it,

Fuel comes in one end at pressure, but is being drawn out by 6 Injectors one after the other, by the time the fuel reaches the other end, you can see how there would be a pressure drop.

As for what pressure you should run, talk to your tuner.

I agree word for word.

[r33_racer]

Its not as bad as you think. The pressure is the same from the regulator back as that is the point from which the pressure is controlled. You would only get a pressure drop if your fuel system cant keep up with fuel usage. If that is the case then you would notice that on the dyno as it would lean out.

We run a single entry/exit rail on our car with methanol and 2000cc injectors and its fine. We used to run a dual entry but its just extra lines and fittings and ultimately not really necessary from what I can tell.

[89CAL]

Its not as bad as you think. The pressure is the same from the regulator back as that is the point from which the pressure is controlled. You would only get a pressure drop if your fuel system cant keep up with fuel usage. If that is the case then you would notice that on the dyno as it would lean out.

We run a single entry/exit rail on our car with methanol and 2000cc injectors and its fine. We used to run a dual entry but its just extra lines and fittings and ultimately not really necessary from what I can tell.

This more so is tru. Given the restriction (regulator) is creating pressure for the injectors, all pressure inside the rail should be equal as long as your pump can deliver.

[Nee-san]

Well in my post I said it may not be necessary but given what I know I feel it would be beneficial but I'm not going to preach on about it, there will always be some sort of pressure drop, you are also helping your pump by working it less.

[89CAL]

Remember that there is still only one line from the pump to the rail, so the pump can only flow what it can get through that first single pipe.

Perhaps it will distribute the fuel better then a single feed I'm jot going to argue that. But you aren't going to get more flow, or if you do it won't be a great deal

And you will not save your pump wear either, it is still restricted by the fuel reg no matter if you have 1 feed or 20 feeds

[DVS JEZ]

You would only get a pressure drop if your fuel system cant keep up with fuel usage. If that is the case then you would notice that on the dyno as it would lean out.

We run a single entry/exit rail on our car with methanol and 2000cc injectors and its fine. We used to run a dual entry but its just extra lines and fittings and ultimately not really necessary from what I can tell.

Not entirely true. U wont notice a lean out on the dyno if its slight and only the rear cylinders. Best way to check is with individual exhaust runner temperatures.

I agree that it is unecassary to run a twin entry but if he already has all the gear it wont hurt to fit it.

[75coupe]

I think I'll run the dual entry setup, may as well its one extra line and a y-splitter...

how hard is it to install egt sensors for each runner for extra tuning info?

would it be worth it?

I plan on getting a wideband afr, but thought egt for each runner as well might help.

[DVS JEZ]

What manifold are u running? If there is access to the runners i just use a infra red thermo gun. Hold it on medium load on the dyno and check. Then do a full power run and check.

[75coupe]

hmmm Im just running stock manifold, im guessin drilling into the cast manifold runners to insert a sensor aint a good idea either.....

ok just wideband afr guage it is then.... now to figure out where to fit all these guages on the dash, (4x defi - oil temp & pressure, water temp and boost plus the wideband afr...)

thanks everyone for the responses...

[r33_racer]

Not entirely true. U wont notice a lean out on the dyno if its slight and only the rear cylinders. Best way to check is with individual exhaust runner temperatures.

I agree that it is unecassary to run a twin entry but if he already has all the gear it wont hurt to fit it.

Yeh im not saying to not do it, I run a dual feed setup myself on the road car because im running two pumps. I get the idea behind it but havent read, seen or heard of a necessary benefit from it, so the point becomes more a preference as both ways work perfectly fine.

Im referring to a slightly harsher lean out. I didnt mean in a slight amount because of the pressure drop across the rail from front to back which is what i think you may be thinking of.

Yes egt's for each runner would be a good way to check that but not everyone has them or a common use for them especially on a road car, though I also have one for each runner on mine lol.

[lachlanw]

theres not gonna be a pressure drop . the pressure is the same from the back of your fuel pressure reg all the way to your fuel pump rotor . (near as makes no fkin difference )