Split fuel rail mod

[zarnah]

can anyone write up how to do the split fuel rail mod? thinking of doing it to my new engine before I put it in my wagon

[Guest]

search other sites. www.rslibertyclub.org has the writeup there

[funkytown]

I just did it last night - based in wellies i will show you..

I have a couple of photos i can post up over the next few days

[zarnah]

mint that would be cool if you could do that!

[funkytown]

PM me with some details and we can sort something

[nt_a_foz]

I also will be doing in the next month or 2 when building my new motor so a how to would be great.

Cheers

[zarnah]

ok well I headed on over to rslibertyclub.org and searched for ages and still couldnt find the thread on how to do it. but then I am pretty damn cabbage on a computer lol! someone with better computer skills than me be kind enough to find it for me and email it to me? [email protected] really want to get onto it, got the boys lined up for the weekend to chuck the engine in so wanna get it done before then...........

[zarnah]

AHA!!!! cheers Ryan!!! I also found this pic which makes it look simple using an aftermarket fuel reg (which I have) anyone know if I set it up like this, what sort of pressure should i have the reg set at? should i just have the adjustment wound right in so it holds as much pressure as possible?

[Guest loren]

43 psi.

[zarnah]

mint! think i got it all sorted now!! i'll get onto it tommorow and see how I go. One more question-- anyone know what the torque figures are when bolting the manifold back on?

[driftrex]

 zarnah said:

mint! think i got it all sorted now!! i'll get onto it tommorow and see how I go. One more question-- anyone know what the torque figures are when bolting the manifold back on?

that setup looks identical to mine, works really well, as for the torque i got no idea i just did it by feel hahaha. and yea i run about 45psi. my fuel pump wouldnt do anything over 62psi.

[ReubenH]

This is taken from my single conversion thread. Same idea between all of them, this is specific to V3/4 manifolds though.

~

Split fuel rail mod:

This is a very easy mod, you need:

8 feet of EFI (Electronic Fuel Injection) hose. 8 ft is really just enough. I think you need 9 feet for BE's and BH's as the filter is not in the engine bay

A few hose clamps (6 should do it, you can reuse the originals for the rest)

2 T sections

A second right hand fuel rail

Now, cut your fuel rails like so:

Now take the injectors out of your old left hand rail, and swap them over. TAKE CARE. There was a great thread on how to take them out, but sadly it was lost in the sever F*** up of 09. Basically, it's a bastard of a job, and it's easy to brake something. just be patient, and use force (as bad as that sounds).

Bolt both fuel rails onto the intake manifold, and cut your EFI to length. I recommend you arrange them under the BOV return/crank case breathers. it makes things tidy and easy to install. Sorry, no pics of how to arrange it. You'll see what i mean though.

Now put the final length of EFI hose on the 2 T sections, loop it around as you don't know what length the supply and returns should be yet. You'll cut it once the manifold is installed, and the engine is in the car. Mark which line is the fuel return, that will be the line with the fuel regulators on it. This line will be longer FYI. Once the manifold is on and the engines in the car, don't forget to hook up the vacuum lines on the regulators too.

That's the split rail mod complete. simple huh

[PhatRS]

 loren said:

43 psi.

With the vacuum line disconnected too IIRC.

[Guest loren]

 PhatRS']

[quote name='loren said:

43 psi.

/quote]

With the vacuum line disconnected too IIRC.

yes, that's the static pressure.

[nt_a_foz]

Reuben your set up is set up differnt to the photo up above by zarnah??

Youve crossed diagonally were as the other ones just gone each end joined to each end..

Does it matter which way??

[Pappu1]

is there an issue if the factory FPR is used instead of an adjustable one?

[Guest]

the difference between the two photos is one runs a adjustable fpr and the other one (2nd one) is using the stock fpr. i dont think there will be an issue if the factory one is used

[Guest loren]

 nt_a_foz said:

Reuben your set up is set up differnt to the photo up above by zarnah??

Youve crossed diagonally were as the other ones just gone each end joined to each end..

Does it matter which way??

Makes no difference. The fuel will still feed to injectors at the same time, then the next two, then go

through the FPR and back to the tank.

One thing I would do differently from 99% of the setups I see, is not put the T's in the middle of the lines,

as you will not be able to access the hose clamps once installed. The hose clamps can get a bit loose after

the first few weeks and start leaking. It will make no difference to the performance to have them on the side.

[Guest]

No won't matter, it is only crossed over because he has two FPR one on the end of each rail.

[Koom]

 ReubenH said:

Now take the injectors out of your old left hand rail, and swap them over. TAKE CARE. There was a great thread on how to take them out, but sadly it was lost in the sever F*** up of 09. Basically, it's a bastard of a job, and it's easy to break something. just be patient, and use force (as bad as that sounds).

Easy way to get the injectors out is firstly take the cap off the top i.e. two 8mm hex head screws, then rotate the injector in the rail. This breaks the seal that has formed after years of being bolted in place and then they are pretty easy to pull out from there.

[rex-leggy]

i didnt even change fuel rails just added regulator to other side with a bit of fuel hose .

did leak at the start not because of the way i did it ws because ya cnt trust other ppl ta

put fuel lines on tight haha . he even didnt put the vac hose on . wata nob .

so just make sure your hoses are tight or ul waste a heap of petrol.

[wildturkey]

i'm looking at the split setup too on my 89 rs leggy........I've been told I can run 2 right hand rails with the factory fpr's (1 on each side i guess). Is this just as good a setup as splitting them and running a single aftermarket fpr?

[Guest loren]

 wildturkey said:

i'm looking at the split setup too on my 89 rs leggy........I've been told I can run 2 right hand rails with the factory fpr's (1 on each side i guess). Is this just as good a setup as splitting them and running a single aftermarket fpr?

you don't need an aftermarket FPR at all unless you want to change the fuel pressure.

The first time I did this I jut used one stock FPR.

TBH I would be worried about using two different stock FPRs... what guaruntee have you got that

they are set the same? although I guess you could just put a pressure gauge on each one... but

still, it's more complex than required.

[Koom]

 loren']

[quote name='wildturkey said:

i'm looking at the split setup too on my 89 rs leggy........I've been told I can run 2 right hand rails with the factory fpr's (1 on each side i guess). Is this just as good a setup as splitting them and running a single aftermarket fpr?

/quote]

you don't need an aftermarket FPR at all unless you want to change the fuel pressure.

The first time I did this I jut used one stock FPR.

TBH I would be worried about using two different stock FPRs... what guaruntee have you got that

they are set the same? although I guess you could just put a pressure gauge on each one... but

still, it's more complex than required.

Prodrive used to use this setup on the Group A cars. There's also alot of people around running two factory regs without issues. If one of the regulators was relieving at a lower pressure than the other, then that would be the pressure throughout both fuel rails (to a certain degree, I'm not gonna get entirely into the fluid dynamics here) and the second regulator just wouldn't relieve.

If you fitted a fuelpump that could supply a big enough flow rate that one regulator couldn't cope, then you could possibly create a situation where one rail "could" be at a significantly lower pressure than the other but the chances of doing that through factory fuel lines is rather slim.

[ReubenH]

 loren said:

TBH I would be worried about using two different stock FPRs... what guaruntee have you got that

they are set the same? although I guess you could just put a pressure gauge on each one... but

still, it's more complex than required.

More complex than required? it's easy as pie and works a treat. And they have stickers on them with a part number, kinda helps in matching them up.