djSL

iTrader: (5)

I plan on running 1000c primary only injectors with my itb setup for simplicity. I may upgrade to staged later on. A couple of quick questions I couldn't find the answers too. I am running An -6 fittings so I plan on tapping the main rail.

1. When running primaries only, I should only have to run my fuel line to the Aftermarket FPR bottom port, then out the side port to the primary rail and then back to the return line correct?

2. Is mounting to the rail a better solution? I would assume if only running primaries you would want the fpr before the fuel rail so it can control the pressure the injectors see.

Aaron Cake

iTrader: (1)

I guess it depends on the model but all Aeromotive regulators I have seen, the bottom port is return.

So you'd run pressure to one end of the rail, the other end of the rail to the Aeromotive side port, then bottom port back to the tank.

I always suggest mounting the regulator to the intake manifold area but of course space will dictate what you can do.

djSL

iTrader: (5)

Huh. I always figured you would want the regulator before the fuel rail. Not that I am doubting you by any means.

Evil Aviator

The FPR must be positioned after the fuel rail if it is to accurately meter the fuel pressure. It has always been this way due to physics. I'm questioning whether you should attempt this advanced project with your limited knowledge base, and you should too.

The fuel should flow like this: Fuel tank > 100 micron filter > EFI fuel pump > 3/8" hard line > 10 micron filter > fuel rail > input to the side of the FPR and output out the bottom of the FPR > 3/8" or 5/16" hard line > fuel tank. If the FPR has two holes in the side, then one of them needs to be plugged (-6 ORB) if using only one fuel rail. If you are not sure then read the directions that come with the parts.

Some racing organizations (NHRA?) do not allow firewall-mounted FPRs. I'm pretty sure that SCCA just requires them to be mounted somewhere in the engine bay. Anyway, check your rule book if you plan on racing.

If you use a stock S4 fuel rail, it can be easily converted to -6AN by using a M14x1.5 adapter on one end and a M12X1.25 adapter on the other end.

djSL

iTrader: (5)

I appreciate the insight. That clears up quite a few things. I have completed numerous engine swaps and builds but I have never needed to swap out the fuel system or messed with AN fittings with the modest power gains I was aiming for. Hence, the questions I had. There is always a first time for everything.

As for the rail, I already have that tapped and adapted.

misterstyx69

iTrader: (142)

hit this:
http://fc3spro.com/TECH/MODS/FUEL/pararail.jpg

(Btw,Thanks TED for the info)

GrossPolluter

iTrader: (1)

I'm pretty sure that is for a safety reason. What is the exact reason? I ended up mounting mine to the firewall, but didn't think about rules since I wont be competing in any events

Evil Aviator

The guidance usually requires the FPR, cool cans, and other fuel components to be mounted forward of the flywheel by a given number of inches so that they are not likely severed if the flywheel fails at high rpm. Like most front-engine RWD cars, the RX-7 firewall is within the danger range, therefore the restriction. This is not a factor unless you are competing under these rules, although you may want to consider this situation if you are revving the engine past 8500rpm.