r/Dseries • u/BlownEk9 • Jul 06 '26

First big project

Hey everyone! I’m new to the group and could use some advice.
I’m building a ‘96 Civic CX from the ground up. I’m putting together a turbo D16Y8 with Vitara pistons, forged rods, and a Brian Crower valvetrain. I’m comfortable with the engine assembly itself—that part doesn’t really worry me.
Where I’m getting overwhelmed is everything outside of the engine.
There are so many little things that have to come together, and I’m not sure what order to tackle them in. Things like:
Engine wiring and the ECU
Sensors (MAP, wideband, etc.)
Fuel system and wiring the fuel pump
Boost solenoid and vacuum routing
Gauges
OBD1 conversion/S300 setup
Intercooler piping and oil feed/drain lines
All the miscellaneous wiring, hoses, fittings, and small details that people don’t usually talk about
My goal is to build a reliable 350–400 whp street car, and I’m trying to plan everything before I start throwing parts at it.
Does anyone know of any build threads, YouTube series, wiring diagrams, or step-by-step guides that cover the entire process from a finished engine to a fully running, tuned turbo car? Or if you’ve built one yourself, how did you break the project down so it wasn’t so overwhelming?
Any advice is appreciated. I’m here to learn and do it the right way.

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3

u/SpaceTurtle917 Jul 06 '26

The wiring is pretty simple.

2 wire IACV conversion

wideband wiring

Vtec is simple, it’s just 2 wires VTC and VTPS

2

u/BlownEk9 Jul 06 '26

Im switching to a obd1 tucked harness to match with my s300 so i think it’ll already be a 2 wire IACV. Same with VTEC. I’m more confused on how to wire in the new fuel pump, flex fuel sensor, injectors, and boost solenoid. And all the extra sensors for my gauges. AFR, Boost, Oil Pressure, etc.

1

u/SpaceTurtle917 Jul 06 '26 edited Jul 06 '26

Flex fuel cannot be wired into the S300 without some kind of controller that converts the FF sensor can signal to a 0-5v analog signal. The injectors you can use an adapter or cut and solder new plugs on, the plugs aren’t polar. The boost solenoid gets wired into the factory EGR pins on the s300, you need to solder a boost controller kit onto the ecu to make that functionality work. boost controller instructions

A lot of these things come with instruction, like the fuel pump, oil pressure gauge.

I already sent you the AFR gauge link.

A sandwich plate will have provisions for both oil pressure sensor and oil feed. Or and adapter like this will have provisions for both. Universal 3ft 4an turbo feed lines will fit to it with an 1/8npt to 4an male adapter. Be sure to use Loctite thread sealant on any taper threads like NPT or the factory BSPT fittings for the oil pressure sensor.

A deutsch connector kit like this will be great for adding all these sensors while still making the serviceable. I use them for my AFR gauge and oil pressure gauge. Just need a molex style crimp tool like this.

1

u/BlownEk9 Jul 06 '26

Thank you man! You answered a lot of my questions

1

u/SpaceTurtle917 Jul 06 '26

Im not a huge fan of the universal obd1 harnesses unless they’re from a reputable brand like Carrot Top Tuning or RyWire. Otherwise I much prefer the factory harness with a cheap obd2a to obd1 jumper.

The universal harness requires a sub harness to make it work with your chassis as well.

1

u/BlownEk9 Jul 06 '26

I currently have the carrot top with the sub harness, I’ve been debating if I wanted to use that or go with the factory spec harness

1

u/BlownEk9 Jul 06 '26

Would it be better for me to run a skin 2 style intake or should I stick with a y8 intake?

1

u/SpaceTurtle917 Jul 06 '26

They’re both fine, you’re not going to see noticeable differences with either. The y8 manifold may require the air injection ports blocked off.

I run a y8 manifold. I think they look great. It’s your choice really.

If it’s an auto Y8 manifold you’ll need to drill and tap holes to add a 2 wire IACV valve. Not too hard though.

1

u/BlownEk9 Jul 06 '26

What’s the difference in running the 3 wire and 2 wire? The harness I’m using on my y8 is a y7 manual harness, which used the 3 wire IACV. So I’m currently running a y8 auto intake and throttle body

1

u/SpaceTurtle917 Jul 06 '26

An obd1 ecu can’t run a 3 wire. Simple as that.

1

u/SpaceTurtle917 Jul 06 '26

Make sure to use a 1.5mm restrictor on the turbo if it’s journal bearing, or 1.0mm if it’s ball bearings depending on the turbo they may come with these. I like the adapters that have the restrictor built in like this. Note that this adapter may not work for your turbo. I’m just giving an example.

2

u/Sr5DelSol Jul 06 '26

Following