p.dicko

Does anybody have any info or pics on converting to parrallel fuel rails on a 92 wrx ,and which pressure regulator to use? shall be doing the work myself ,using fuel hose and Y connectors.any help cheers.

Slowboy Racing

There is plenty of recent info on how to do this and where to get the parts needed.

A couple of links here.

NorthUrsalia.com: Series To Parallel Fuel Delivery
https://www.scoobynet.com/general-te...light=fuel+mod

dazdavies

iTrader: (22)

I got mine from Zak at Mocom Racing - Performance car and trackday products

The braided lines and fittings were sourced locally but the two rails were from him here's a pic of mine

If I recal they are £130 but he'll give you £50 back if you send him your standard ones. So £80 for a pair is a bargain and they are excellent quality.

Also would use either an SX, aeromotive or fuel labs regulator. stay away from the FSE ones.

Here's a pic of mine in situ



Although mine are phase 2 he does phase 1 rails too. give him a call.

Daz

p.dicko

thanks for the advise got a better idea now , but still not sure about the return feed to tank, and plumbing up a different pres reg ?

MrRA

I've decided on this mod. The OE fuel rail setup really is awful.

Will probably go for the Perrin setup or similar.

dazdavies

iTrader: (22)

Its a doddle if using parallel rails.

Basically your feed from the fuel filter which is fed from the tank goes to a T piece that splits to the back of each rail.

The front of each rail goes to a T piece which is then fed off to your regulator. The regulator then feeds back to the tank return thus keeping the fuel in the rails at a constant pressure. If thats not clear enough I'll draw a detailed diagram. If you want me to do that just PM me.

Basically you're reversing the flow too.

Setting it up is a doddle providing you have a Fuel pressure guage.

Need any help give me a shout.

Daz

harvey

iTrader: (48)

Why go to the expense of parallel fuel rails if you are not going for mega power?

MrRA

That is a point but surely increasing the efficiency of the fuel system - which some consider very poor in OE setup - can't be bad thing.

I'm doing personally and I won't be running mega power either. I practice continuous improvement in work and as such am always looking to gain the few % here and there, it's in my nature I'm afraid

But as I know from this forum that you extensive experience with these cars, could you maybe expand upon your comment just to give the whole scenario as regards when and when not to go parallel, as it were. I've read a few cases where the loss of engine was put down to number 3 running lean, the last to receive it's fuel thanks the 'series' designed OE fuel rail setup.

davedipster

Has anyone put pressure gauges on the std rails to see what each injector gets under high load? some on here have rubbished the idea of cylinder 3 going lean because of poor fuel pressure cos the std setup is rather good.

dipster

frayz

iTrader: (7)

Personally mine will be a parallel setup for peace of mine when under high load conditions.
Also coming from Zak @ Mocom racing :

catalunya199again

whats wrong with the fse i have one and its not missed a beat and working fine on my setup and im running 320bhp

dazdavies

iTrader: (22)

Prior to my engine build I had the standard rails. My theory is that the Walbro pump over powered the standard reg thus letting too much fuel back to the tank causing Cyl# 1 to run lean and I lost a piston due to det.

The parallel rail elimiates this problem by feeding each rail at the same time with the same quantity of fuel.

As for FSE's I have heard several reports of eratic behaviour with them and several well documented and catastrophic failures.

Haven't heard of any with the SX and fuel lab variants

Daz