What does this line near my fuel rail do?

[Pixel6]

Hi guys, first post.

I recently picked up a 91 Silvia, and am in the process of going thru it and restoring some parts, and upgrading others.

While pulling the turbo to upgrade to the T28, I was looking at fuel management upgrades like the Walbro 255, and 555cc injectors, new FPR, and I came across this I think fuel line system (red lines, and part I am holding). Anyone know what it’s called and what it does? Has a filter on it, and goes to to a little module that’s just zip tied in place.

Would like to understand what it does, to determine if it’s unneeded Japan emissions stuff, or practical to keep.

I looked in the service manual, but without a part name, or reference to what it does, I can’t seem to find this in the book.

Thanks.

[nisileighty]

The thing you’re holding is an Apexi pressure sensor. Does your car have an Apexi AVCR boost controller?


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[Pixel6]

Ah hah!

Yes sir it does.

This is my first turbocharged car, so I am very new to boost concepts and the supporting devices. Just watching tons of build videos and reading forums. So many little things that make the whole system work well. It’s crazy.

A lot of new parts are going in over the next few weeks to support the T28 turbo upgrade I’m doing including a hallman boost controller, AEM Wideband, EFI ECU, MAP sensor, Air temp sensor, Fuel pressure sensor, full color display. (I kinda went bananas on Black Friday)

Thankfully I have a few specialty shops that are helping me out (I’m doing as much of the work as I can myself, but it’s the easy stuff that’s hard to mess up like short shifter, radiator, seats, bushings, wheel spacers & studs etc.) and both shops specialize in drift car builds. One is more fabrication, repair, maintenance, and the other is for the ECU, Tune, and supporting devices to be wired.

Anyhow, I’ll find a way to clean upgge Apexi sensor routing away from the throttle cable with its current zip tie setup, and perminantly mount it.

(I was misinformed of it being emissions related when purchasing the car.)

Thank you kindly for your help.

Don’t judge me too hard lol. I just want to learn.

[nisileighty]

Welcome to the schassis and turbo would man.

You’ll want to make sure you get a tune before you do much, if any, driving with the aftermarket ECU, MAP, injectors, etc. If you upgrade your cooling system, clutch, exhaust, and other things you’ve listed, you should have no problem hitting the 300-320hp mark.

My current setups. 330 whp SR20, 450 WHP RB25
https://uploads.tapatalk-cdn.com/20171210/3524985c4d8a2aa3edc22198dd288bad.jpg
https://uploads.tapatalk-cdn.com/20171210/a133b5b17a894f3de4de743b1622b942.jpg

[Pixel6]

The thing you’re holding is an Apexi pressure sensor. Does your car have an Apexi AVCR boost controller?

Hmm. I just read that more closely. It has an Apexi boost gauge and a turbo timer on the A-pillar, but I’m not sure there is an Apexi boost controller installed anywhere. The gauge can work without a controller via the stock waste gate on the turbo assembly yea?

I’ll take a look closer look tomorrow. I’ve only had the car 2 weeks, and it’s mostly been at a shop waiting on parts I ordered after I found it had a bad gasket on the stock turbo. So took the turbo & manifold off, then decided on getting the T28 (which came in today... awesome). Manifold just came back from the ceramic coating place.

So yea, learning a lot in a short time frame.

[nisileighty]

Is the gauge mechanical? In other words, does it have a vacuum line going into the back of it, or only wires?

I’m uncertain of every Apexi product that uses that specific pressure sensor, but I know for sure the AVCR does, which is why it’d make sense if your car has one. Who knows?

Trace the wire to the source.


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[Pixel6]

Well, here’s my list of things that I’ve gotten for it so far. (After a few comments)

The plan is to install the new turbo with reclock plates, and the boost controller (bypassed), fuel pump, fuel pressure regulator, then pull the clip on the stock waste gate to run nearly no boost pressure and drive it to the tuner, who’ll do the injectors, ECU, wideband, sensors, display etc... then have him get it to his trusted tuner.

So tomorrow it’s the radiator, short shifter, and anything else we can knock out that is sort of pre-turbo install.

Here’s that list. Did my research seem to lead to good choices in your opinion?

Ahem;

NRG steering Lock:
Whiteline HICAS lockout bar:
Razo (3) pedals:
Razo dead pedal:
Energy steering rack bushing kit:
Energy racing subframe bushing kit:
Pioneer Nav System:
1080p Backup camera:
B&M short shifter:
H&R 15mm wheel spacer:
H&R 25mm wheel spacer:
Koyo N flow Radiator:
P2M Brass shift bushing:
ISR engine valve gasket:
Energy suspension bushing kit:
Oem Nissan/Garrett S15 T28 Turbo:
ISR suspension arm package:
Dif 28 turbo reclocker:
NRG seat harness bar:
(2) ISR full engine gasket set:
Aem wideband gauge:
(4) Toemi 555cc injectors:
Hallman boost controller:
(20) ISR wheel studs:
Walbro 255lhr fuel pump:
Cometic head gasket:
ISR Fuel Pressure Regulator:
(8) Energy Racing Manifold Bolts:
ISR Turbo Line kit:
Ride height adjustment:
4 wheel Alignment:
Moog ball joints:
(2) Sparco Evo ii seats:
(2) oem conversion Brackets
(2) Sparco 6 point Harness:
(2) Billet aluminum seat mounts:
(2) Install Hardware kits:
Pro48 EFI ECU:
Plug in pin kit (ECU):
3 1/2 bar controller:
MAP sensor:
Air temp sensor:
Fuel pressure sensor:
Controller with Full Color display:
ECU coupler for clean rewire:
Comm cable for laptop tune:
Manifold ceramic coating:
Door strikers:

So basically I got the larger Nissan S15 T28 Turbo for ~300WHP with a custom tune,
suspension upgrades, a stereo, and some nice seats.

Soon I’ll order a Z32 brake conversion setup, a Cusco bolt-in cage (maybe half cage depending on my head height with the Sparco seats), 2 way LSD, and stronger clutch.

[Pixel6]

Is the gauge mechanical? In other words, does it have a vacuum line going into the back of it, or only wires?

I’m uncertain of every Apexi product that uses that specific pressure sensor, but I know for sure the AVCR does, which is why it’d make sense if your car has one. Who knows?

Trace the wire to the source.


Sent from my iPhone using Tapatalk

I think only wires. I’ll investigate closer in the morning. I’m quite curious now if there’s a controller lurking about the engine bay.

[nisileighty]

Nope, the AVCR looks like a big calculator so you’ll know. It also requires wiring to the ECU for RPM, TPS, etc for the boost by gear/speed feature.

If the gauge only has wires, that’s what the sensor is for.


Sent from my iPhone using Tapatalk

[Pixel6]

Welcome to the schassis and turbo would man.

You’ll want to make sure you get a tune before you do much, if any, driving with the aftermarket ECU, MAP, injectors, etc. If you upgrade your cooling system, clutch, exhaust, and other things you’ve listed, you should have no problem hitting the 300-320hp mark.

My current setups. 330 whp SR20, 450 WHP RB25
https://uploads.tapatalk-cdn.com/20171210/3524985c4d8a2aa3edc22198dd288bad.jpg
https://uploads.tapatalk-cdn.com/20171210/a133b5b17a894f3de4de743b1622b942.jpg

It already has an ISR down/mid pipe setup (cat delete). Not sure on the muffler, but it’s a 2 outlet design that looks pretty good to me.

I need my engine bay to look that clean. So nice :)

[nisileighty]

but it’s a 2 outlet design that looks pretty good to me.



Sounds like a stock muffler to me.

I need my engine bay to look that clean. So nice :)
Thank you. You picked a good platform

[w0nderbr3ad]

Might be a check valve/filter for the map sensor.

[nisileighty]

Might be a check valve/filter for the map sensor.



This. The little orange spinning top looking thing on the red vacuum lines is just a filter.

[Pixel6]

This. The little orange spinning top looking thing on the red vacuum lines is just a filter.

Yup, got it all sorted out today.

Installed the Walbro 255 fuel pump, and am really happy with the soldering job I did. Unsoldered the old connection and soldered straight to the spades. Replaced the fuel filter with a new one from a z32. Looked to be the same size as the one I had on there originally. I thought the s13 fuel filters were smaller than the Z?

Anyhow,

I also unscrewed and pulled off the “T” on the end of the fuel rail, and put on an ISR fuel pressure regulator (single “L” elbow). Rerouting the vacuum line (including the filter) that used to go to the T on the end of the fuel rail, and am running the vacuum line over to the FPR I mounted on the shock tower in the morning to prepare for the new T28 turbo I’m putting on in the afternoon.

Also bob at the shop also got the Koyo radiator mounted... but the shroud sits back about 1/2 an inch too far on the top bolt for some reason. So he needs to make a little bracket for it.

I put on the B&M short shifter as well. Not a fan of those 2 back bolts and the knuckle-busting , but love the feel of the new lever and brass bushing, especially since there’s almost no play on the lever now.

And bob got the front tension rods installed. Waiting on the rest of the suspension kit until we can take the subframe off to replace all the bushings.

So yea, finish up the fuel system tomorrow, install the hallman boost controller and get the turbo and new lines on, and she should be ready to get to the other shop for the MAF, sensors, ECU and tune!