Has anybody had any luck with any of the aftermarket FPR adapters that allow you to replace the existing FPR with a converter from the nipple-oring setup into the fuel rail to some threaded connection? If so, what brand and what sizes work? I am trying to fit an adjustable FPR on my fuel rail. Also, if I cant find something that works, can I just put my adjustable fpr after the stock regulator increasing pressure throughout the whole system?
How much extra pressure are you going for? And for what purpose? You CANT put it directly in line after the existing one, as the outlet from the OEM one is low pressure with a hose clamp and not a crimped fitting, so it would most likely leak / blow off when the outlet pressure built up.
I have seen oem style variants for Audi and Volkswagen sold by ATPturbo and I have seen home made variants though they simply use a stiffer spring for increased rail pressure. I don't know of any that are adjustable sold specifically for the celica. You can buy AN Banjo fittings to suite Toyota fuel rails that can be ran to a external fuel pressure regulator.
I thought that the FPR was held on not with a banjo fitting, but a nipple/o-ring fitting with bolts through connected flanges. And yes, I realize that the current way the stock FPR is set up would leak under 55psi, but I would make a change to that fitting to prevent leaks. It is a lot cheaper to modify an FPR than it is to tap the rail. Unless there is an adapter that exists like this: http://www.turbosmartusa.com/wp-content/uploads/2011/11/FPR-Ada-ToyotaSubaru.jpg I would be left with that option.
Our FPR is located on the left side of the fuel rail, right behind the oil filler cap. Its a threaded fitting with a lock nut and copper washer. On top it has a fuel outlet to return to the tank which has a hose clamp, and above it is a vacuum hose. The vacuum hose assists pulling the valve open at low throttle as you do not need high pressure, and when you open up the vacuum is less, and the valve will maintain a higher fuel pressure. Depending on how much extra pressure you want, you may be able to cheat it with an additional in line reg, and put a proper hose clamp on the line to stop it leaking. It would probably work quite fine for a few more psi. You could also remove the vacuum line, but that would only increase at low throttle and not much at WOT Ideally I would remove and replace with a new after market one. I can get the thread and bolt size if you would like, it won't be for a few days until I can get over to where my spare motor is to check it though. Then you could get s banjo fitting to suit it and run whatever you like!
