1.6 Harness into 94 1.8

[Short Story] My sort of built 92 chassis got into an accident and there is no way to recover my lost, besides taking the parts off and transferring into another shell. A friend of mine is donating me his spare chassis (94/95 M edition) because he has no use for it. He is taking the drive train, brakes, engine harness, and suspension components.

Has anyone swapped their 1.6 engine harness into a 1.8? The reason why I want to do this, is because I already modified many parts of my harness to run a 1.8 (NB) tps, IAC (NB), toyota cops, and had the car safely tuned. It is currently making 295whp 271tq

[Parts List of 1.6 Chassis]
Engine:
+99' Engine (1.87)
+ARP Head studs
+ARP Main Studs
+2001+ oiling system
+ACL Race bearing set (Main, Rod, Thrust)
+Fel-Pro Headgasket set
+M-Tuned H-Beamed Connecting Rods
+84mm - 9:0.1 Wiseco Pistons
+Supermiata HB
+1mm Oversize Valves (Supertech) Exhaust and Intake
+Supertech Springs, Retainers, etc
+Garage Star Water Pump Pulley (1.8)
+Fidanza Adjustable Cam Gears - Silver
+Fab9 Solid Motor Mounts 88D
+NGK Nickle 1-Step colder plugs Gapped at .030 (BKR7E - O'rileys part ref: 4644)
+ 94 1.8 Alternator
+GarageStar Alternator Pulley
+ 2000 NB Starter
+323 GTX Turbo PCV
+Rotella T6

Intake:
+HellaFababrications Custom "Race" Aluminum Intake Manifold
+Skunk 2 Throttle Body
+2.5" Intercooler piping
+HKS Mushroom/Superflow Air filter

Exhaust
+Custom Equal Length Bottom Mount turbo manifold- Fabricated by HellaFab
+3" Stainless Steel exhaust (V-Banded)- Fabricated by HellaFab
+3" Stainless Steel piping (Cat delete- V-Banded)- Fabricated by HellaFab
+3" Stainless Steel Vibrant Muffler (V-Banded)- Fabricated by HellaFab

Cooling
+Begi Spacer w/ fittings
+Water Neck Delete - Freeze plug + Custom Block-off plate
+Coolant re-route (Followed RevLimiter's +Write-up) w/ Escalade hoses
+Ebay hose Splicer
+Flipped lower water pump housing
+Fab9 Stage 2 Intercooler

Turbo
+IWG = Internal Wastegate
+BorgWarner EFR 6758 (3" exit)
+Turbosmart BOV Fixed 50/50

Fueling:
+Deatschewerks (sp?)200 fuel pump
+1000cc Injector Dynamics
+FM Dual Fuel rail

Electronics:
+Megasquirt PnP v2 engine standalone
+Turbosmart Manual Boost Controller
+Innovate MTX-L Wideband
+IAT sensor/Speed Density Sensor
+Custom Toyota Coil-on-plugs (1.6)
+Autometer Boost Gauge

Both cars are OBD 1, so it should be a good swap.
How much of the harness is he taking ?
Just the engine part ? and you will have a better time doing this.

It would be easier if you just bought him a harness and have him leave the one in the car alone.

I cant imagine swapping the entire harness.

Hope he does not cut it out.
Good luck

Quote:

---

Originally Posted by 90blue

Both cars are OBD 1, so it should be a good swap.
How much of the harness is he taking ?
Just the engine part ? and you will have a better time doing this.

It would be easier if you just bought him a harness and have him leave the one in the car alone.

I cant imagine swapping the entire harness.

Hope he does not cut it out.
Good luck

---

He's taking most of the harness. All there's left is the interior harness.

Will I need to only transfer the 1.6 engine harness? (Fuse block, ecu harness plugs, etc..)

you'll probably need to swap EVERYTHING, or do a lot of cutting/hacking/praying

Seems like too much effort, IMO

Silly question; why don't you transfer everything from your old car to the new one?

I've swapped the front harness on my car for a clean one. It isn't difficult, but if I were to do as you are, I would swap over the entire harness, including the rear. I would mark and label connections, look at factory service manuals between both cars, and take lots of pictures. You will probably want to swap over the dashboard, if intact, too. The issues you could run into are mounting points for the front harness behind the dash. The 1.8 cars, the ECU in behind the passenger seat, the 1.6, as you know, is in the foot well. So, strip both cars, lay in you harness, reassemble.

Quote:

---

Originally Posted by HarryB

Silly question; why don't you transfer everything from your old car to the new one?

---

This is the original plan. Since I have the dash and everything else that works as a 1.6 harness.

Quote:

---

Originally Posted by kung fu jesus

I've swapped the front harness on my car for a clean one. It isn't difficult, but if I were to do as you are, I would swap over the entire harness, including the rear. I would mark and label connections, look at factory service manuals between both cars, and take lots of pictures. You will probably want to swap over the dashboard, if intact, too. The issues you could run into are mounting points for the front harness behind the dash. The 1.8 cars, the ECU in behind the passenger seat, the 1.6, as you know, is in the foot well. So, strip both cars, lay in you harness, reassemble.

---

I figured it wouldn't be too bad. I memorized most of my harness (1.6) since I wire tucked 2 1.6 and replaced the engine harness numerous times (for other Miata enthusiasts)

Ah I just realize the new shell has ABS and power steering. Hm. Possibly cap the ps lines on the rack and move the brake lines from the 92 shell to the 95 shell.

Or remove ABS, swap over front subframe?

Suspension are interchangeable, just remove the sensors.

OTOH….ABS is a separate system, you may could keep it.

Quote:

---

Originally Posted by kung fu jesus

Or remove ABS, swap over front subframe?

---

Would it be easier to "loop" the ps lines that are on the steering rack? I was thinking swapping the brake lines from my 92 and use the calipers/rotors/pads (since they are already 1.8). The ABS module is alerady damaged.

Thank you Mazda Roadster members for the help.

Quote:

---

Originally Posted by ADOBOMiata

Would it be easier to "loop" the ps lines that are on the steering rack? I was thinking swapping the brake lines from my 92 and use the calipers/rotors/pads (since they are already 1.8). The ABS module is alerady damaged.

---

You can do that with the PS rack. It's pretty well documented around the web for guidance.

If the ABS is damaged, me personally, I would remove it, but weigh out the possibilities of salvaging it to make it work.