Project SC : 2JZGTE ECU Wiring into SC300 Guide

To prep the SC for the GTE swap, I’ve sourced a MT GTE ECU and a Aristo ( JDM 2JZGTE ) engine harness. For those doing this swap into a SC300, the wiring is a lot easier than the typical S-Chassis wiring in that many of the vehicle’s functions and wires are the same.

Given the similarities between the SC300 and the MKIV Supra, this is really no surprise, however you will need to lengthen and extend the third plug or body plug as well as rewire.

This body plug disconnects from the sc300 along the firewall, next to the ABS module and near the windshield.

Upon splicing open this harness, you will notice many similarities with your Aristo harness.  The large connector on this harness connects to the SC300 body plug and also the small plug that leads to the ECU.

For ease of wiring installation, we are eliminating the following wires (Traction Control D17,  Pressure sender ( Dummy Light ) D10, and Transmission Shift indicator D1)

Use the following pinout and match the corresponding colors accordingly.

courtesy of clublexus.com. not my pic

The Aristo harness and ecu plugs :

For a pin by pin how to, refer to this chart here :

Now with your engine harness properly wired, you may now remove your old SC300 harness and install your GTE ECU and plug it in. Next up, we start yanking weight in preparation of motor swap, as well as installing a new Cometic head gasket, ARP head studs and selecting our turbo setup.

Happy boosting!

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Project SC : A New Beginning… Or is it?

I have to admit that moving from the nimble and athletic S14 chassis to a heavy pig like the  Z30 ( or Soarer if you are in Japan ), hasn’t been an easy transition for me.

It’s taken some time, but the comfort of the SC300 and overall finish make for an excellent street car and comfortable cruiser. However the issue of curb weight / power to the wheels is still undeniably present, but nothing a 2JZGTE swap won’t fix.

First however, I’ve got to ditch the belt driven fan assembly, because…. well…. it’s stupid. Not only does it constantly spin and create a drag on the rotating assembly, but its freakishly huge and bulky, taking away precious engine compartment space.

Upgrading to a slimline fan assembly

We’ll be using a Mishimoto fan shroud, and 2 12 inch dual speed fans for A/C connectivity ( California is hot! ) as well as a fan controller for maximum reliability.

This will be replacing this honking huge piece of crap.

For a fan controller, I personally love the Derale lineup of controllers which feature a safety bypass, dual speed control as well as your choice of probes and temp senders.

For this install, I have opted for the push in style of connector for ease of install. Why? well the 2JZGTE is a very high temp motor, and given the turbocharged nature of this motor cooling is of the utmost importance, especially on a daily driver.

However a true 3 core radiator is not in stock currently from Mishimoto or Fluidyne, two of my favorite radiator companies. So for the meantime, we’ll be rocking this push in style sender until our permanent radiator arrives.

This install is berry berry easy sir.

First we crack the 12mm nuts on the fan assembly, while keeping the tensioner tight on the belt itself. There are 4 10 mm bolts that hold the shroud in place, you may or may not need to remove your factory battery to remove the shroud.

Once these have been loosened, then undo the tension by turning the belt tensioner clockwise. Slip the accessory belt over the pulley and then proceed to carefully remove your factory fan and shroud.

Install of the new assembly is very straightforward, outside of a fabricated driver side mount.

After wiring in the ground to the Derale relay, we start up the SC and get it to operating temps very quickly. The slimline fan not only makes the engine bay look more clean and organized, but gives me at least 5 more inches to move and wiggle when the GTE motor is ready to go in.

I also ditched my Stern ST7’s for another set of Stern wheels, this time in 19 inch and ST11. With 19×8.5 in front and a 25 offset with 19×9.5 in rear with a 30 offset gives me a good stance and is cheap enough so that I won’t cry when a rim bends due to California highways.

Not really looking to change much more of the looks about the car until after my motor swap is completed. Lots of work on that front so I’ll be busy no doubt there.

First however, I’ve got to prep the wiring for the GTE swap, which means lots of wires and a lot of cursing. Fun.

Next up : Wiring up the 2JZ engine harness and combining with the SC300 body plug for a true plug and play installation.

Happy boosting!

Project SC : Setting the Stance with Megan LP Coilovers

Welp, it’s about that time to get off my lazy behind and finally get some work done to the SC. While the car was lowered by the previous owner, the KYB shocks weren’t up to the kind of punishment that only Bay Area highways can provide.

Where else to go for a good coilover set that won’t break the bank? After much deliberation, I went with the LP series Megan Racing coilovers for the MKIV Supra.

These Megan LP coilovers provide a 32 levels of damper force adjustment and separate spring perch height and shock length adjustments. Without camber plates however, it essentially ensures I cannot lower the car TOO low as the SC300’s stock camber adjustments do not allow for anything greater than -3 degreees.

First we begin by removing the rear trunk area and deck lid, allowing us access to the rear shocks and the gas tank.

Now undo the 3 14mm nuts holding the top perch of your coilover in place. With these nuts removed, you can now go under the car and remove the 19mm bolt that goes around the lower control arm.

After removing that 19mm bolt, you can now pull out the old setup and put in the new Megan Coilovers.

Depending on how low you decide to set your SC, you may or may not have an issue with the rear sway bar linkage not fitting.

To remedy this issue, we’ve gone ahead and installed some BLOX adjustible end links to tie things together.

After lowering the car, the LP’s put me as low as I need to go ( maybe a tad TOO low to be honest ). With the car’s stance figured out, we move on to POWER!

Next up, swapping in the Aristo 2JZGTE and WIRING it up… yay?

Happy boosting!

Project SC : A new beginning

Well, maybe not a NEW beginning, but Project 2JZ-240SX has certainly taken a turn as the S14 undergoes surgery, I begin tearing into my new whip, a 92 manual SC300.

The car is monstrously heavy compared to the S14, and with the blown shocks and other Mickey Mouse work done to the SC, it rides like a boat.

Response is dull, steering feedback is lacking, and the car plows into every corner, pushing until the limit, when at long last I can bring the heavy rear end of the car around. Sadly the car doesn’t have enough steering angle to compensate, and the heavy nature of the car makes it difficult to step out as easily as the S14 did.

Compared to the athletic and nimble S14, it’s clear what the SC will become, a nice street car with a 2JZ swap in it. I am considering BAR legality currently, to see if it’s worth the hassle of legalizing the motor upon swapping into my SC.

The paint on the car is in decent shape, the tan interior is very clean, albeit ugly as sin. I make plans on picking up black interior, but first I’ve got to address some issues with the car, such as the headlights not working or the starter working.

Upon further inspection, it seems as though the driver side harness has been chewed up due to be lowered.

It shocks me that to this day, people still aggressively lower their cars down without considering the engine harness.

First, undo the 2 10mm bolts holding the engine harness to the frame, these are located toward the rear of the driver side fender well.

Taking these 2 10mm bolts out will allow you to pull *GENTLY* on the harness and give you enough slack to push the harness up and out of the way. Secure it with zipties or metal loops, I’ve opted for McMaster Carr ground straps.

After I’ve re-run the harness, I take apart the harness to repair the wires that had been run through and damaged. Now wrap up the harness and tuck it away, make sure to give yourself plenty of clearance so that your rims and tires don’t touch the harness ever again.

Next up, I tackle the tan interior of the SC300.

It’s clean.. .but too…….. tan.

You must undo the shift bezel, undo the screws that hold the center console in, and pop out the entire center console panel allowing you access to the radio and climate control mounting bolts.

After undoing those bolts, now remove the climate control and radio as a whole to give you access to the rear screws and dash vents.

I also decided to move over the MOMO Race wheel, because deep dish is so much more nicer and should go into my S14, which is dedicated track only use now.

With the new black panels installed, the car looks much better but the tan seats and carpet are still an eyesore.

Next up, getting rid of the stock seats, carpet, and putting the SC on a diet.

Happy boosting!