Just thought I'd ask for opinions on my AEM FPR mounted at the end of an S4 rail. I'm mounting this on my S5 TII because the stock regulator couldn't handle the additional idle flow from a rewired Walbro. I suspect the return line restriction was just too small.

And how long are the stock S4 bolts holding the rail on? They must be at least 40mm long due to the cast mounting bosses.

 

you're the first I've seen to mount an aftermarket FPR to an OEM rail on an Rx-7, although it's pretty common on other cars.

 

Will you be able to put everything back together without the FPR in the way is the question.

 

^ Indeed. My measurements say I'll fit, but the true test will be tomorrow when I try to drop it in. There's not much wiggle room either way.

 

And will he be able to adjust it when its all together.

Keep us informed.

 

Not bad, hope evrything fits good!

 

Well, I made it work with a custom bracket, but wouldn't recommend this mod. Pulling the UIM is a bitch as it is, and installing a FPR at the end of the rail makes it even more of a PITA. I did it for the stealth installation tho, and it beats a giant FPR mounted to the firewall IMHO. Setting the fuel pressure is no problem since the adjusting screw faces out with plenty of access.

An elbow for the fuel pressure gage sender provided clearance to the throttle cable bracket, but adds even more clutter to an already crowded spot.

Enjoy the pics.

 

Do you know whyno one does? Is the flow rate of the OEM rails rather low hence a bigger FPR will do no good without upgraded fuel rails

 

no.

 

Ok if the oem fuel rails flow fine how come no one upgrades theFPR, is it not nesascary until really high horse power applications

 

Actually I know quite a few TII and FD owners who upgrade the FPR. They just typically mount it to the firewall or near the frontside of the secondary rail and run -6 hose to it. i wanted to try something different and needed the additional return flow and pressure adjustability due to the fuel pump upgrade.

Eventually I'll run a variable speed pump controller to minimize the return flow.