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Hi SAU,

I was looking on my S2 RB25DET stock plenum and i found a pipe that is protruding out of the plenum looks to be a vacuum inlet however i am not sure what it connects too and what this pipe is actually used for, Does anyone know ? i have attached pictures below. I tried searching however nothing came up.

post-66083-0-96078200-1376551241_thumb.jpg

post-66083-0-45276800-1376551250_thumb.jpg

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Fuel pressure regulator. This is the best and most accurate point to get the signal from as its the closest available before combustion. I also tee of this for my boost gauge but not boost controller.

Edited by SargeRX8

Thanks for the reply. Just to clarify my FPR is connected to the bottom pipe via the black hose should I leave that how it is (all stock RB25 have it like that) and connect boost gauge to the pipe that's exposed or T it off?

Why is there two pipes for the FRP ? Should the top one exposed be used by a boost gauge?

The boost guage uses one on the opposite side at the firewall, I have the fuel reg and the boost controller connected by a tee piece but that outlet in your pic is not on my series 2 plenum, looks like you have one extra outlet there.

post-70965-0-13434200-1376611893_thumb.jpg

Edited by AngryRB

Yeah I thought so normally people just T from the stock boost gauge connection, and I have only seen this extra outlet on one other RB25 :/ just need to know what it can be used for it what it should be connected too! Everyone seems to think either thing it's for boost gauge or FRP

Edited by DarkRyda

so it was just sitting there with nothing attached? Would have idled heaps bad. Our have you messed around and forgot how it goes back together?

No mate the engine hasn't been running I just pulled it out of a car doing an engine swap and i would like to know what that pipes for so I can hook it up when I do the conversion in a few weeks.

It was just sitting there I presume the previous owner removed something before he sold me the car, it was a write off got hit from the back I kept the engine and parted out the car. Hope that helps clarify everything.

Edited by DarkRyda

cant be a series 2 plenum then cause its different to mine, I wonder if a series one plenum looks like that at all,

must be for something that needs vacuum, not sure if R33's have ABS, just a random thought if that's related or not.

neos have a couple of lines like that and what looks like a couple of regulators (only one is a regulator though) http://www.skylinesaustralia.com/forums/topic/426682-confusing-r34gtt-fuel-rail-pics/

maybe that could help?

heres a photo of that port on my neo plenumattachicon.gif20130819_155601.jpg

Thanks for the help, where does that connect to? looks like some sort of regulator? where does the bottom regulator pipe connect to?

I have attached another view if anyone's interested.

post-66083-0-28914900-1376910917_thumb.jpg

Edited by DarkRyda

It's definetly a S2 engine out of a 1998 GTS-T most don't have that on the plenum iv only seem a few RBs have it!

Thanks mate ill look into the fuel damper. Where does the bottom of the fuel damper connect to mate?

Edited by DarkRyda

It's definetly a S2 engine out of a 1998 GTS-T most don't have that on the plenum iv only seem a few RBs have it!

Thanks mate ill look into the fuel damper. Where does the bottom of the fuel damper connect to mate?

Not sure if they just a straight swap but maybe previous owner put a series 1 plenum on a series 2 motor or maybe its just a whole series one motor together that previous owner may have changed at some time??

If you are talking about the fuel pressure regulator then the vacuum line on it connects to the side of the intake plenum.

Not sure if they just a straight swap but maybe previous owner put a series 1 plenum on a series 2 motor or maybe its just a whole series one motor together that previous owner may have changed at some time??

If you are talking about the fuel pressure regulator then the vacuum line on it connects to the side of the intake plenum.

It's definetly a S2 motor as I have previously stated. No ignitor for coilpack on the back of engine, S2 coilpacks with built in ignitor, S2 engine Loom, S2 ECU, Pink Label AFM (3pin),TPS.

I know what series the engine is I just want to know what the extra pipe is for I think your getting off track the plenum itself isn't the issue here it's the extra perturbing pipe just want to know what to do with it block it off or use it for boost gauge or connect it to a fuel damper etc....

Edited by DarkRyda

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