Rx7TyreBurna

iTrader: (1)

Well, my problem is that I want to use an external FPR on my car. I have an S5 fuel rail with the FPR cut off, and I have an S4 fuel rail with a 5/16" barbed fitting on the end that used to have the FPR.

Problem is, the holes where the bolts go through to hold the fuel rail down don't line up on the S4.

Welding a barbed fitting onto the end of the S5 would be very difficult. There is probably 2-3mm of space on the bottom end where the injector goes into the fuel rail.

So, because neither seem like they are going to work. I was wondering how hard it would be to make my own fuel rail? If I bought some square aluminum and welded barbed fittings to each end, and then drilled out holes for the injectors and somehow fit the little round metal fittings into the fuel rail. Would this work, or is there more to a fuel rail then I think?

I can get a piece of 1"x1"x4' square aluminum for about $10. Welding etc would be pretty easy. I think the hardest part would be getting those round fittings to slide in there and be air tight.

Thanks guys. Just trying to make this work. My other idea is to cut the mounts off the S4 rail, and weld the S5 mounts onto the S4.

13b4me

As long as it stays pressurized, a larger rail isn't going to hurt you at all. The question is why are you installing an aftermarket FPR on a N/A car? You don't mention any mods that would necessitate one.

Rx7TyreBurna

iTrader: (1)

I was told that if I had the walbro 255 in there, the stock FPR wouldn't be able to let enough out and it would cause my injectors to shoot a little more fuel because of the higher pressure.

The FPR I got only cost $40, and it has a little fuel pressure gauge on the FPR. I also like knowing that the fuel pressure is set correctly.


Thanks for responding.

13b4me

You don't need a FPR for a Walbro.

TeamWireRacing

You can just cap the end of the S5 rail where the FPR used to be (making doubly certain that the end is sealed). Then tee the FPR into the return side where the return line comes out from under the intake on the driver's side.

I'm mounting my FPR to the LF strut tower.

ISC Racing will even sell you a modified rail if you don't feel like messing with it yourself.

http://www.iscracing.net/2nd_Gen_Parts.htm

Second item on the right.

classicauto

iTrader: (3)

And he doesn't need a walbro for his N/A.............unless its a monster bridge port or something

But FWIW, KG parts makes aftermarket rails for these cars.........not sure if they fit N/A's though.

Rx7TyreBurna

iTrader: (1)

LoL... i know. I have to type it constantly.... i am thinking about changing my sig to say it....

My old pump was dying, so I had a walbro laying around from another mazda. 87 mazda 626 LX. So, I checked and they were exactly the same. So, I popped the walbro in and called it good. But people are saying it can make me run too rich because it creates too much pressure or something.

13b4me

You could sell the Walbro and buy several N/A pumps, or maybe even a TII pump if you were feeling froggy. :p

NZConvertible

You don't need one, but you should get one unless you like pissing away fuel needlessly. Even on a Turbo, but expecially on an NA, unless you have some way to tune the mixtures electronically you need to reduce fuel pressure to the stock 36psi static pressure to avoid this.

But your last post is right on. For all the cost and messing around with FPR's and fuel rails, just buying the right pump is a much smarter move...

13b4me

Yea I was just basing that on his sig, which states he's running an SAFC-II. That's plenty of headroom to get his fuel pressure in check. I wouldn't recommend one for a TII by any means, but they are perfectly suited to leaning out the stock N/A map.

Thanks that's basically what I was getting at.

NZConvertible

They're perfectly suited to leaning out the stock TII map too.

13b4me

I just don't like bandaids. To me they're in the same class as an FCD.

NZConvertible

How is a fuel controller a "band-aid"? It's not there to fix anything.

And before you get on the standalone soapbox, do you hear anyone telling you how if you wanted a sports car you were dumb for buying a Mazda instead of a Porsche? Same flawed logic.

Both are interceptors, so they are in the same class.