It will fit in the rail but the return tube may need to be bent. My question is why you want to use one?
first off... like the signature.. it is.
but from what i know of my pressure regulator, it's pressure is only changed by a: the pressure from the fuel pump, b: when the injectors spray, and c: by the vaccuum hose coming off of it. and vaccuum is only effected by engine bore size, vaccuum solenoids (the parts in the vaccuum sys controlled by the ecu), and if there's a leak.
but you're using a different ecu all together.
the nismo fuel regulator will be in line with your engine's train of thought.
you've got JWT cams, and a JWT sr20 ecu... i'm guessing because where you're going with all this is that you're getting more power out of an engine... no s#!^ huh? lol,and some of this might be no brainers but i don't know what you need to know.. well when you change stuff on your engine (like the ECU that controls and tunes everything) you have to go through and make sure everything is lined up. this is a guess, i don't know your engine, know the specs, or know the programming for the JWT sr20 ECU, but i'm thinking the GA16de's pressure regulator doesn't have the same output flow as the SR's... and if the programming was a little off.. then it's trying to get a fuel pressure regulator that's designed to work with one ECU, to work with a completely nother one that's made for performance. hence, why they told you to put on a Nismo regulator.. if you're running rich.. maybe lower flow? (which is wierd cuz it'd mean the slower engine uses more fuel, but it could also mean that the pressure isn't high enough for a faster engine, so you're getting less fuel.. but then it should be lean) *someone help me out here, i'm rambling* i gotta read up on fuel regulation again.. hell, it could be something with the vacuum solenoids that operate the pressure regulator not having the correct info coming from the ECU.. in fact though... i have to reread my vaccuum diagrams.. if i remember correctly mine's always under vaccuum, so there's no solenoid to adjust the pressure regulator... but i gotta look again. i know the pressure is constant for the most part. maybe two positions/ two pressures it switch from but those two can't change of it will act all wrong... these basically set up the correct pressure for the injectors so that when the injectors get their ECU signal (via the cams-to-CPS*crankpositionsensor*) they spray out the correct flow for amount, duration for amount, and damnit... something else.
but from what JWT told you... i'm thinking they're thinking that either you just need that performace pressure regulator and it'll be all good, or you need them to rewrite some of the programming, or the whole system isn't fully in tune yet cuz you need to change out some other components to get the correct amount of power for that ECU.
another thing to look into that you're going to have come up later on down the road.. if you're trying to get SR power from the GA, then you need to realize what exactly is being programmed into your ECU... what it is, how it reactes via sensors... what about this.... you say you're running rich... by running a reprogrammed SR ecu in a GA... think of all the things that haven't been modded or switched out yet, that the AIR/FUEL RATIO coming from the ECU will be restricted by.
your throttle body and airbox, your intake, your injectors, your fuel pump, fuel filter..... ...and after all of that... your combustion chamber. know what i mean? course this is why making a race car takes so much.. the parts are expensive and if you only put on one part of a system at a time it's like trying to drive a truck around that started out with stock tires and you're buying/installing the monster truck tires one at a time.
this is where some ppl mess up, and not saying you have cuz i don't even know the engine's full history, what all you've done... etc. ...but when you start changing the harmonics of an engine, you have to do the whole system as a whole unless you're willing to deal with stuff that's a little off.
....you put on highflow injectors w/o changing the rest... they won't have the fuel pump, the filter, the pressure regulator, the bigger combustion chamber, and the correct amount of air in the mixture to support them... same thing with anything else...
you drop cams in your engine to play with the AIR/FUEL... you need to play with all the other cooperating components on the car which you did by putting on a reprogrammed SR20 ECU... but now you need to tweak it out.
you need to line up the rest of the engine's train of thought. but don't forget, you keep shoving more and more fuel into the cumbustion chamber and you won't have enough room for air to mix with it. err.. i mean you'll be rich. *that's right right? rich means you've got too much fuel... ugh.. i need coffee...* looks right, gonna leave it..
check this out real quick..
MSD Rich/Lean Indicator - JEGS
something you'll need the more you play with your engine. but it's real primitive, just gives you a warning, it's not some $600 piece of software that'll explain in ultimately hard to understand bits of every piece of info your engine tells your ecu... but it lets you know right away that you're out of tune. If the oxygen level is high, a red light comes on to indicate a lean condition; a green light indicates low oxygen and a rich condition.
Your theory about fuel pressure is not correct at all. The fuel pump is mechanical and the fuel pressure regulator simply regulates fuel pressure based on an orifice size and vacuum. The ECU cannot and does not control fuel pressure or the amount of pressure created by the fuel pump. All OEM Nissan ecu's are programmed to run and assume 3 bar of fuel pressure.lol, seems to me like you know your car better.
you could teach me some stuff..
the mixtures and ecu rev codes are somethign i can't wait to learn if i ever get there.
what do you mean exactly when you speak of "only at 11" or 12,13,14... on the fuel..
sometimes i feel like i'm learning all this crap just to fill up my head... came so close to gettin to play with all that shi stuff on my 240, and now i'm back to square one...
tell me some about your air/fuel ratio...
FIRST OFF, the idea of droppin a reprogrammed performace ECU onto a similar sized, slower engine is magnificent. totally do-able but i start to think of all the incongruencies.. all the little defects in doing somethign like that.
unless like you, you switch the cams at the same time. but i mean more like how they did it... got all the sensors to work with it. you know what i mean?
which is why i said i could remember whether or not there was a solenoid attached to the vacuum line going to the Fuel Regulator...Your theory about fuel pressure is not correct at all. The fuel pump is mechanical and the fuel pressure regulator simply regulates fuel pressure based on an orifice size and vacuum. The ECU cannot and does not control fuel pressure or the amount of pressure created by the fuel pump. All OEM Nissan ecu's are programmed to run and assume 3 bar of fuel pressure.