Thoughts about the fuel rail and FPR

Ok... got a question... if you disconnect vacuum from the stock FPR, will it stop interfering?

Reason I ask is my fuel rail I've got installed "works" at the moment, but I'm sure the FPR is not up to snuff (rail is off a CA20E, i.e. not a normally boosted engine). What I wanted to do was just buy a Z32 FPR, because its normally a fuel line in fuel line out, i.e. it doesn't bolt directly to the fuel rail like the DSM and CA18DET ones do, and just put it AFTER the fuel rail before returning to the tank... the Z32 also has a dampener... which works in a similar way but on the other side of the fuel rail keeps fuel flowing in smoothing and the FPR keeps the rail pressurized...

Z32 FPR:
http://courtesyparts.com/Merchant2/graphics/00000001/z32/22670-00001.jpg
On this one, the line at the top goes to the rail, and the line at the bottom is the return to the tank.

Z32 FPD:
http://courtesyparts.com/Merchant2/graphics/00000001/z32/22675-00001.jpg
On this one, the bottom at the top goes to the rail, one on the top goes to the incoming fuel line.

The FPR is normally mounted upside down compared to its shown positions when installed on a Z32 engine...

I just PITCHED a set of these I had the other weekend when cleaning my garage... they would have been perfect to try, though they were rather old... =( (I took them off my Z32 back in 2000, so yeah, they were a little used, hehe, but it would have been cheaper than buying new ones to try).

These are unfortunately not cheap solutions... they run ~$65-68 a piece... =( but... it might be a viable solution to trying to custom fab a fuel rail and buy and adjustable FPR. These units normally work on SIX 370cc Injectors and are normally fine for SIX 555cc injectors. Normally guys only install adjustable FPRs on Z32 when they go with HUGE turbos on the Z32 and have 555cc injectors and they need the additional fuel pressure to compensate for the boost levels they're running.

Just wanted to see what you all thought, and if anyone had considered this stuff before... ^_^

How about the "rising rate" type from www.nismoparts.com They got an adjustable, rising rate, universal one for $107......part number 22670-RR710. Looks similar to the one in your photo.....

how about the obx adjustable fpr i am using with my fuel rail.. goes for 85bucks on ebay all the time

The OBX one is not a Rising Rate type....is it?
I could be wrong, but isn't a rising rate fpr good to have when applying more boost?? I always heard this anyways :dontknow:

The OBX one is not a Rising Rate type....is it?
I could be wrong, but isn't a rising rate fpr good to have when applying more boost?? I always heard this anyways :dontknow:

well if you start with a non turbo platform then ya its good but if you already have boost then it better to use a 1psi boost=1psi fuel.. keeps the computer happie cause if not you will get really rich when you get up in the 10+psi of boost and you will more then likely lose power up that high in boost

i used the CA20E fuel rail and FPR on the CA20ET project and never had any problems with the car ever having fuel problems, thats also because I never boosted past 9psi. But i think the stock FPR works fine.

well if you already have boost then it better to use a 1psi boost=1psi fuel.
So what exactly does that mean? Will one like your OBX fpr rise with boost pressure, or does it maintain and stay at what ever psi you set it to regardless of boost?
I would think yours would still rise with boost pressure as long as the fpr had a vacuum source.....right?

it has a 1:1 ratio of boost to fuel pressure increase...

lets look at this with an example: say you boost 15psi of boost pressure that means you system as it sits(stock) has 38psi at idle plus another 15psi for the added 15psi of boost since the stock fpr is 1:1...this is technically the best way to add the needed fuel when you increase positive pressure..

now from a raising rate fpr....most ones are 1:2 so 1psi of boost equals 2psi of fuel.. so we have 38psi stock and then 30psi of added fuel pressure form the boost thats 68psi on your system.. no that way more then it should ever see...

the reason people use a rasing rate is because its almost a cheap way to be able to support a big turbo.. lets say we where to throw a t3/t4 and boost 13psi.. the stock fuel system would lean out.. but with a raisgin rate you may be able to squeeze enough fuel thru the stock system to keep things stoich...but what you really need to do is get bigger injectors and then use a 1:1 ratio fpr with the new larger injectors.. al you rally need the adjustable fpr for is the use a new rail and to set the pressure at or a tad above normal pressure

hope that makes sense if not i can explain more

Got it..........thanks