Forums Forums Builds & Mods Mazda 323 GTX – WRC for the Common Man – Part Deux Reply To: Mazda 323 GTX – WRC for the Common Man – Part Deux

Cameron AlbeaCameron Albea
Post count: 537

I figure we’re way overdue for a GTX update. Header is taking time as we’ve been busy at Composimo, but here’s a few pics of it in progress.

PRL Motorsport Flange

Starting to take shape. This is more or less where it stands today.

In the meantime, I’ve been working on the ECU and electrical system.

The megasquirt has been pretty easy to map out. Thankfully, I have an excellent guide written by Ethan Ott for SpitfireEFI (Ethan, thank you tremendously) on how to install the Megasquirt ECU with the 323GTX harness.

Only complaint about the MS system…..anyone see what’s wrong? That’s right! The diagram is backwards. I found this out after about 20 minutes of backprobing the db37 looking for a specific ground…that was fun.

Next step was to get the old harness out of the car. If you ever do anything with engine harnesses or plugs, anything, get this tool kit. Easily saved me an hour of work.

Harness out and exposed.

Next up was mapping the harness out and figuring out where it all went. I didn’t know where this was heading, but it seemed like a good idea. The full wiring diagram in the service manual was invaluable.

It was around this time that I started thinking about what the megasquirt could and couldn’t run. The Evap system was first to go as the solenoids are operated from the stock ecu. Since it’s old enough, and since the county I’m in doesn’t have emissions, it’s not a big loss. Don’t worry, we’ll still have some kind of vent for the gas tank.

So much room behind the intake manifold now. So what do you do with the 4 plugs that would’ve gone to those solenoids? Well, no sense in keeping them.

Everything cut, heatshrunk, then taped back neatly to the rest of the harness. I left enough room on both ends to reverse this in the future if need be.

This…started out as just removing a few plugs. It did not end at a few plugs.

14 in total were removed. This really cleaned up the harness and will make it a lot easier to tuck in the engine bar. This is where we’re at now. Plans are to get the gtx harness mated to the MS harness here in the next week or so, everything is already mapped out so that wont take long. With that, we’ll end there. Thanks for reading.