Mazda MX-6 Forum banner

1 - 3 of 3 Posts

2,743 Posts
Discussion Starter #1
Here is a short list of the things you will need to successfully complete a LX/DX -> GT swap. After the list of things needed, I will briefly explain how to do it (how i did it).
I HIGHLY RECOMMEND that you get a "donor" car that you know ran while the engine longblock worked, and get all of the electrical parts from that car.

Parts needed from GT (if i think of anything else ill add it)
  • Engine (complete engine: distributor,IM, etc)
  • Exhaust manifold,turbo,o2 sensor housing,downpipe (if not included in "engine")
  • Transmission
  • All engine mounts (i believe you can use the same rear transmission mount, but its just makes things simpler if you have ALL the mounts for the GT engine)
  • Intercooler/IC piping.
  • TB boot (could be included with IC piping)
  • GT spindle assemblies
  • GT axles
  • GT jackshaft/intermediate shaft
  • GT shift linkage and torque arm (i just grabbed the complete shifter and everything)
  • Complete GT wiring harness from the same year engine.
  • All pressure and vac sensors from the firewall.
  • Ignition/coil unit.
  • GT ecu from the same year as engine
  • Boost gauge.
I removed my old engine with a cherry picker and cleaned out the engine bay. Pulled all the wiring, sensors, ignition, and engine mounts. While i had the old engine still up on the hoist I removed the transmission, starter, PS pump, alternator, and a/c pump. Picked up the new engine and put all the accessories on that engine (ps pump, alternator, a/c pump), put on the starter, and put on the clutch and transmission. Attach the intermediate shaft to the rear of the engine.

The next step was to get the engine bay ready for the engine. Its actually very easy to get the wiring harness through the firewall and connected to the ECU. Once those were installed, i put all the sensors on the back wall and bolted down the ignition unit. I left the wiring harness disconnected from anything so i could have room to play with it if i needed too. The engine mounts bolt right up.. leave the engine side loose and flipped up so you can get the engine in. I had to drill some new holes in the bumper/radiator supports to properly bolt the IC in.

Dropping the engine in was a little bit tricky. The engine has to be cocked at a major angle so that the tranny if facing down. Slowly lowering the engine in and righting it at the same time (recommend at least two people doing this). Once i had the engine reasonably close to where it would sit height wise, i pushed it as far forward in the engine bay as I could, to make it easier to connect the vacuum hoses to the sensors on the fire wall. Connecting the upper wiring is fairly self explanatory: plug the connectors that fit together, together. Since you removed the lower wiring harness, it shouldnt be too hard to figure out how it connects to the starter. Once I had all the rear wiring connect, i slid the engine back into place, and bolted down the engine mounts. From here inside the engine bay is basically just connecting all the plugs, and making sure things look right.

The only things left to do are to put on your GT spindle assemblies, attach the clutch line and bleed it, attach the shift linkage, attach your boost gauge, hook up all the IC piping, and pray that you did everything right.

With all this being said, I recommend that you dont attempt this swap. Just buy a GT.

  • Like
Reactions: Mazdaman92

4,971 Posts

4,971 Posts
AdderMk2 said:
You CAN turbo the LX motor... but do the obvious checks first... compression etc... pop off the oil pan and do a bearing inspection, make sure none of your rods are cracked...

keep in mind that you still need to
#1. provide an oil feed (get the oil line from a GT and drill/tap the appropriate spot on the back of the block
#2. profide an oil drain (same as above, but you only need a single fitting available at autozone or your local car shop, and its on the front of the block)
#3. coolant feed... (again ^^^^ just above where the oil drain is)
#4. get the GT metal coolant pipe that runs from the water pump outlet to the rear of the motor, it follows along the side of the engine near the EGR tube

fuel will be an issue for you.. i recommend getting in touch with someone who knows about ECU systems.... if you would like, contact Fastest95PGT about possibly running a megasquirt to control your fuel... thus saving you a really messy wiring job, and not having to [dizzle] with changing ECU's

The two of us are setting up our cars with the MS-1, I may decide to run the V.3 board, but Jeff may slap my nuts and make me settle for a v2.2 board..
(we are currently working on a solution to the 1g spark control issue)

*edit* if this post doesnt get me karma... im gonna :cry:
Give it to him here:
1 - 3 of 3 Posts