Head Unit Relocation IR Repeater


Moshi moshi.

I decided I didn't really enjoy the tablet install, so this will now be the 3rd revision of the MX-5's audio setup.


Goal was to create an even simpler interior, might even delete the AFR gauge, by relocating the head unit into the boot/trunk. I still wanted to retain full audio controls as well as Bluetooth and USB connectivity. My old audio setup worked well but the sound wasn't the greatest, probably from the lack of pre-amp/equiliser control.

Although I planned to mount the head unit in the boot, I still wanted full control of the unit, this was achieved using an IR repeater. Normally used in home theatre setups. Simply have the repeater eye in the cabin, and the repeater transmitter in the boot with the head unit.


First thing was to make up an extension harness that goes from behind the tombstone and into the boot. I used roughly 5 meters worth, and I went with something more flexible, conductor is 38/0.15 strands. And I've just terminated the ends with connectors.




Pictured below is the IR receiver unit, I've mounted this just above the rear view mirror. The harness was plugged up, and you can also see the little USB power adapter that's powering the IR Repeater.


This is where the head unit will be mounted in the boot. I've made a cardboard template for that little spot and will make it out of marine plywood and covered in automotive carpeting. You can also see the IR transmitter double sided tape right in front of the head unit's IR receiver, and the right angle USB extension cable.


The completed setup, showing how much simpler it is now. The other end of the USB extension sits in between the driver and passenger seat, and the remote control has some double sided velcro to keep it easily accessible.


Further updates...


B18C2 Swap


About time I modified the daily, needs more VTEC!

My EG5 Civic originally came with a D16Y1 (VTEC) attached to an automatic gearbox. And recently it's been overheating a lot, I suspect the water pump needs replacing as the thermostat and radiator are in great condition.

The engine I have going into the car is an Australian delivered B18C2 that came out of a Integra VTi-R, and the gearbox was originally from a B16A2. I believe it has shorter ratios than the B18C2 engine.

Gave the valve cover a thorough clean and than paint.




The engine also received a new water pump, sump gasket, head gasket and a whole bunch of new bits.


Next up was the wiring... The engine has a mixture of OBD2 and OBD1 parts, as well as some JDM bits but Australian OBD1 ECU. So I had to modify the harness a bit to get everything to work.

Wiring was stripped back and tagged.


Harness was than dummy fitted. I wanted to do a harness from scratch, but budget and time restraints didn't allow for it, maybe I'll do one later for fun.


For some reason, the engine had ODB2 injectors. So I made a custom injector harness and separated it from the main engine harness. The harness and ECU are wired for a VTEC Pressure Switch but the engine didn't have one, so that had to be deleted by running the pressure switch wire directly to the VTEC Solenoid wire.



Had to fix the alternator plug wiring too... Damn workshops doing dodgy wiring.


And the engine removal starts... More updates next post. I also removed the dash as I have to replace the automatic pedal box with a manual one, and some wiring things had to be done too. Dash doesn't have to be removed, but only takes 20mins and makes everything so much easier.


The B18C2 swap requires running a few extra wires to the ECU from the shock tower connectors, I just fed these through this grommet.


Since I have a few spare Honda harnesses to use, I de-pinned them to use in my car. Takes a bit more effort, but produces a better end product. O2 wire goes to pin A6, Knock goes to D3, Alternator Control to A16, and IAB to A17.


Next part of the wiring involved running the IAB wire and reverse switch. Again this could be done pretty quick but I decided to take a bit more time and make it neat. Everything can be accessed from the connector shown below, it's under the dash behind the fuse box.


The light green and yellow wire (two top wires) are for the solenoids in the automatic gearbox, but in manual cars they are the reverse switch wires. Both these wires goto the ECU at position A17 and A19, I just de-pinned these and they'll be wired to the reverse switch wires found in the centre console which was used by the automatic shifter.

The red wire (directly under the white/blue wire) was added and wired to the ECU pin A17 for the IAB.

That's all for now, more updates soon!


SR20 MX-5 Build Update


Previous info on the build:

We've finally started doing more work on my friends SR20DET MX-5 build! Very excited about the progress today, next week we'll be replacing the NA dash with a NB one. Everything bolts straight in but wiring has to be modified.

Interior stripped out, NB carpet cleaned up and going into the NA shell.

Next up was the main body wiring harness, this was previously stripped back and modified. This includes a proper relocation of the engine bay fuse box, cleaned up engine bay wiring, and separating the factory combined engine and body wiring.


Boot Light

Just a quick update, I've installed a boot light and it's amazing! Please excuse the image quality, they were all taken using my phone.

Install doesn't take very long and everything is plug-and-play. Kit comes with a LED mounted on a stainless steel bracket, boot switch and wiring harness.

Boot Light Kit -

Photo taken without flash at 9PM.

I also removed my tombstone to give it a quick coat of Plasti-Dip, the surface was a bit too rubbery/grippy for my liking so I gave it a quick wipe with some interior detailing products. Worked out very well 🙂


Centre Console Update & TSI

Small update!

I finished up my design to relocate the power window switches after deleting the centre console. The switches are automotive grade and will include wiring harness using crimped connections. A revised template for the carpet will also be included and will cover up the tunnel and fuel/boot release levers. The panel is CNC laser cut from 1.6mm thick stainless-steel sheet and all supplied hardware will be stainless-steel too.

Testing so far has been very good, functions like factory (no auto feature), and I find it easier to reach than the factory location for the switches.

Centre Console Delete Kit now available:

Below are some photos of the first prototype.

I now stock TSI kits, Turn Signal Intake. Replaces the factory light assembly, and provides a good source of cold air into the engine bay. The vents have both LED parker and indicator lights.

Not too bad hey!


ECU Mounting


I've been dreading this part of the build, was never sure how I would do it and make it neat. But everything is coming together now and so I had to do something.

Because my custom fuse/relay panel sits where the ECU normally goes, I've had to install the ECU in the glove box. It's not a bad spot to put it, just my solution isn't "clean" for my liking.

I had to remove all the internal sides of the glove box, gives much more room for the harness to hook up. I'll also make a short serial cable "pig-tail" so I can hook up the USB connection.

All the studs were epoxied into place, not very clean and not sure if it'll be strong enough. So I might go over everything with some fibreglass, any thoughts?

Test fit was good too, but I'll let it cure overnight before I tighten up the nuts.

I also decided to use the stock tombstone, goes much better with the rest of my interior. So the KG Works tombstone will be up for sale soon.


ITB Build – Part 9

Did a bit of wiring today, can't do much until my head and manifold adapter gets back from machining.

Doing continuity checks to make sure I was terminating the correct wires.

Was only able to terminate the coolant temp sender, water temp gauge and oil pressure gauge senders. Everything is heat-shrinks and sleeved, no tape will be used in my engine harness because I hate that shit when it gets old and sticky.

Sorting out where wires will go and fitted up the fuel pressure gauge.


ITB Build – Part 7


Another slow week for me, didn't get to do much and haven't been able to start the engine harness because I'm waiting for some heatshrink to arrive.

So I got the engine wiring in and quickly laid it out, my spare head went on with the Toyota COPs so I can mock everything up.

The ECU side of the engine harness, blower motor back in and the AC bypass pipe.

The main power harness going back to the battery, there's multiple runs of cable because I've relocated all fusible links next to the battery. So the entire length of cables are protected, unlike the factory cables... pretty slack of Mazda.

This is the FD RX-7 fuse holder, works great and hangs right off the battery clamp.

Connected the steering column up so I could test out the body wiring. Headlights, indicators, retractors, brake lights, horns, wipers and water sprayers all worked perfectly first go!


ITB Build – Part 3

Made little progress so not a huge update, continued removing the old wiring harness and attempting to clean up the engine bay.

Where I was at since last update and now the wiring is out.

Looks so bare with so much stuff taken out.

The new wiring slowly going in, new battery/power wires going in too.


ITB Build – Part 2

Some more progress today 😀

Had a friend come over to help strip out the interior since my cracked dash and ripped carpet will be getting replaced. Also makes it easier to get out the old wiring harness. Enjoy the madness below, sorry for the lack of photos.

Seats and center console out.

Steering column dropped and dash completely out.

Everything nearly out, just need some more free time to get the wiring harness out.