babycrab

it's time I make a build thread. this will likely take the course of years.

i've always liked these cars, pre 97 especially, and managed to find a good example last year.

the primary goal apart from keeping the car in its best shape, rust free, and maintained, is keeping the car as factory as possible and period correct in the looks department. no kits, no aftermarket wheels, no bright white/blue led lights, no aftermarket head unit/steering wheel/seats. you get the idea.

quick intro on the car:
-1993 sc300 / federal emissions / no traction control / automatic
-black onyx paint with tan interior
-just under 69,000 miles on the clock
-I am the second owner; it had been garaged its whole life and was serviced at the dealership it was originally purchased from, which is also the dealership I purchased it from

general performance parts/goals:
-na-t
-r154 (jzx100 variant)
-3.76/3.92/4.08 lsds (I like to have options)
-big brakes (ls400 front, tt rear)
-tt wheels
-hks or ohlins coilovers
-tt sway bars
-trd strut bar

miscellaneous parts and projects:
-rustproof / powdercoat subframes and other undercarriage components
-full paint/glass/metal polish and seal
-needs some pdr
-new passenger door molding and its continuation piece on the quarter
-fix the trunk liner that's sagging at the top
-replace L shaped plastic base of drivers seat
-either fill license plate holes and respray front bumper or get a 92-94 front bumper without license plate holes
-rayno s9 tint on all glass
-make cornering lamps both stay on whenever low beams are on
-exterior door handle light like clublexus user Luxor has done but in a soft yellow white
-power folding soarer sideview mirrors
-soarer sidemarkers
-bluetooth integrated into factory radio
-antenna up down function integrated into one of the existing buttons on the factory radio
-back up camera with screen integrated into factory rear view mirror
-lexus tan 3 spoke non perforated steering wheel from an early rx300 or late sc300/gs300
-soft amber footwell lighting for driver and passenger
-factory key with button to pop trunk, and hold unlock to roll down windows/hold lock to roll up windows.

priorities as of April 26, 2020:
1) acquiring rare and discontinued items (compiled from lists above)
-tt wheels (acquired)
-trd strut bar
-tt or trd sway bars
-3.76, 3.92, 4.08 diffs (entire diffs or ring gears and pinions, with t2 torsen center to swap around)
-ls400 front brakes, tt rear brakes
-passenger side bottom door molding/continuing piece on quarter
-plastic base piece of driver's seat
-92-94 front bumper without license plate holes
-power folding soarer sideview mirrors
-soarer sidemarkers
-5 speed cluster (acquired)
-lexus tan 3 spoke non perforated steering wheel
2) keep car in top shape and rust free, do cosmetic/misc projects from time to time
3) auto to r154 swap
4) suspension/bushing/wheel/brake work
5) motor work (this will be way down the line, seeing as there will always be parts and support for 2jz)

i've acquired most of the parts for the r154 swap, the only parts missing are the clutch disc, pressure plate, and slave cylinder. of all the parts, the only used item is the front half of a driveshaft from a mk3 turbo 5spd. the only non oem items are a braided stainless clutch line and a marlin crawler vss. i'd like to get the swap done by the end of summer, although school is my top priority.

all the leather was treated with leatherique. all the gaskets and weather stripping from the hood, trunk, sunroof, windows, and doors were refreshed with Krytox GPL105. got some burgundy floormats which match the wood well.

I have both volumes 1 and 2 of the service manuals which have electrical diagrams in the back but I wonder if I should also get the standalone electrical wiring diagram book, if someone can elaborate on this that would be great.

i'd like to thank some people for helping me get my foot in the game.

KahnBB6
Luxor
Shayy
renko_sc300 (IG)

KahnBB6

iTrader: (5)

Whoa, excellent start to your project! A 69,000 mile clean and original SC300! A lot of great specs you have in store for it!

What I would suggest is to focus on the wheels, brakes, suspension, R154 swap and other electronic modifications first so as to set the car up the way you want to handle more power and bring out the best in the chassis.

Here's where I'll get more in depth on several points to consider as you plan this build going forward. Just suggestions or merely food for thought:


Perhaps the one thing not to do is add the LSD to it with your stock diff if you will not plan to wait several years before you'll have turbocharged power. I did that but I also took eight years before I completed my GTE swap and so I still feel that building a 4.27 LSD diff for use with an NA engine was entirely worth it. However that was only because I had no clue when I'd actually achieve a running GTE swap. But if it had only been a couple of years' wait I'd wouldn't have done it.

Also, with a Kaaz 2-way LSD on California's roads that have a lot of baked in tire residue from the near constant sun just be aware that those roads can under some circumstances be extra slick when it rains. A 2-way is in a sense more predictable than a Torsen T-1 1.5-way in those conditions but the steep downhill sections on the I-5 or 101 and some of the highways much further out of Los Angeles always made me sweat bullets when it was raining after my LSD swap.

I never make any sudden driving movements on those downhill sections in the rain with an LSD equipped SC. Everything always smooth, deliberate and without any sudden throttle application. Also your tires are of HUGE importance. I swear by BFGoodrich Comp2's now but I had a couple of truly nightmarish spinouts on rainy CA roads with my LSD on BFGoodrich KDW's (which are great track tires but *horrible* and dangerous in the wet).

Always check the tire reviews on TireRack and pay close attention to what owners of performance RWD cars similar to the SC have to say about them in the dry and wet.

Since you, like me, have a non-TRAC SC300 your safety and control in the wet all comes down to you, your car's setup and your choice of tires.

.....

You've got the right approach to make a great stock looking sleeper out of this car! The NA-T approach, being in CA, I can only suggest you should make it as visually reversible as possible to go back to NA if necessary. Keep your stock GE manifolds, cats, EGR equipment, etc. You should also plan to swap out the '93 oil pump for a 1996+/GE VVT-i oil pump (at the same time you prepare your GE oil pan for the turbo oil drain) so that you can choose to have use of a factory crank angle sensor with a 2JZ-GTE ECU. A Treadstone IS300 manifold can keep everything really tidy in there.

I'd also recommend looking into what you'll need to convert an Aristo 2JZ-GTE fully dressed engine to USDM spec with the JDM CT20 twin turbos but of course it gets more expensive and can be a bit of a treasure hunt. Although starting with an Aristo 2JZ-GTE Non-VVT-i in good shape as a base for USDM conversion can be a good way to do it much cheaper than the way I did it.

Oh, also replace the steering rack bushings with Figs Engineering polyurethane units to tighten it up again and rid the car of any steering rack "shimmy". Similarly IF your front lower control arm bushings are gone due to age even with 69k miles on the chassis, get some new 93-96 Supra MKIV front LCAs and that will also bring the car's original handling prowess back into line.

Sway bars... I feel like 93-96 Supra TT sways are a fine choice. You'll need OEM MKIV rear subframe mounts or you'll need an aftermarket equivalent of them (though I don't recommend solid mounts for a street SC). The 93-96 Supra TT 22mm rear sway bar is enough. The Supra TT's front sway bar is not necessary but actually does compliment the rear slightly better than the SC's front sway bar does. You really have to know your SC's dialed in suspension (with a Supra TT 22mm rear bar already installed) like the back of your hand to tell the difference between how an SC300 front swaybar and MKIV Supra front sway bar both feel but there is a subtle difference.

The other thing the Supra TT's front sway bar does is provide a bit more clearance for the TT's (and Soarer 2.5GT's) stock side mount intercooler under-pipe just behind the radiator. Not really needed to fit aftermarket FMIC piping but it is needed to fit a stock SMIC system. Actually there are two deviations from "stock Supra" to make an SMIC setup work in an SC: 1) use a Soarer SMIC and have it rebuilt by a speciality IC shop.... and.... 2) use just the Soarer style IC under-pipe. All the other stock IC piping can be Supra TT spec.

....

The backup camera and display approach you have is exactly what I'm planning to do soon. May I recommend actually replacing the entire factory Gentex rear view mirror in favor of a Gentex aftermarket model P/N ADVGENM5S. It has a built in compass, auto-dim, rear view camera with 4:3 screen in the left corner capable of accepting 720 or 1080 camera inputs. It's around $300-$350 depending on where you buy it.

If you want the Homelink version you can get the more expensive ADVGENM45S. Or... you can get a used sun visor Homelink unit off ebay and custom install it into your driver's side sun visor similarly to how late model SC's had this optional feature on some cars. This latter approach is what I did several years back. There is a DIY on it listed somewhere that I followed. The wiring can be drawn off the SC visor's vanity light electrical connection I think.

Either aftermarket rear view mirror install will require taking your car to a body shop or professional glass shop to have them remove the stock SC rear view mount from the windshield glass and install a standard "V" rear view mirror mount.

This rear view mirror swap is a project that I have yet to get into but I've collected a bunch of threads that in bits and pieces go into how it can be done wiring-wise. I'll send those to you when/if you wish.

As for a camera I am going to take a page from Toyota and use my OEM 1992-1996 flat rear wing to install a Coolint flush mount adjustable rear view camera and pull its 12V Switched wiring from the old Lexus Phone wiring in the driver's side of the trunk near the antenna. I've taken electrical readings for which wires to use and I've picked up a spare set of connectors and wires to make a patch harness for this but I haven't gotten into it all yet. However I'm happy to share the notes and findings with you if that's something you plan to run with before I get around to making a DIY about it.

For a wingless SC you'll probably need to stick with a license plate rear view camera but you could easily mount the flush "eyeball" Coolint camera into a drilled trunk hole also. But to preserve original body work I think a license plate camera might be better with no early style OEM trunk wing.

...

The only other two changes I would suggest on the interior (other than custom panels for gauges if you want to monitor oil temp, oil pressure, volts or boost) would be the seats and the steering wheel. This is personal preference.

If you're in SoCal and especially Los Angeles or really any place with mountain roads I recommend another style set of front seats (re-wrapped in the SC's stock interior leather color if you like) and a different steering wheel.

The reason IMO comes down to control. Once you have your SC dialed in as a much more capable handling machine and if you prefer to enjoy it on technical mountain roads the stock SC seats really do not hold you in place very well as they have almost no side bolstering at all. Stock seats in a Honda Prelude I owned before my SC were nothing special but they did have adequate side bolstering and held me in place during technical road drives in the mountains. However the stock SC seats just let me slide around a lot.

I am going to guess they are not easy to come by now but my solution was a ratty pair of tan Supra MKIV seats since they bolted right in and took only a little extra work to make the basic power driver's seat and seatbelt light functions work (I made a DIY thread for the latter some years back). But really any seat that works, looks good and which has side bolstering will do the job just as well.

The steering wheel swap to an IS/MR2/Celica/Matrix style three spoke reduced the overall diameter from the SC's stock LS400 sedan sized steering wheel to a more compact design which has better contours for the "6" and "9" grip positions. It's really common but a much more driver oriented steering wheel. And it's bolt in. Since my interior is tan and those steering wheels all come in black I found a black SC upper and lower steering column cover and that made the interior look like it could have come that way from the factory. The airbag center is from an 01-05 IS300 and there's a particular airbag adapter that is used to make it talk to the SC's airbag ECU. Common swap.

For a technical driver's SC300/400 those are the only two major interior changes I think are worth considering just to have better control. But again, it's all personal preference.

...

I can't wait to see you run with this! Take things one step at a time and definitely transform the brakes, wheels, tires, suspension and transmission first. You will have a completely different SC300 once you've done just those things and dialed in the new handling characteristics

...

Edit: I also recommend upgrading your headlights to a 4200K HID plug and play system at minimum. The stock Halogen system is OK but rather dim and not very safe. Especially out west and in the mountains I found this to be pretty important.

Your stock 1993 bumper's cornering light housings can probably also be converted into fog lights (although the cornering light wiring will no longer be used and you will have to buy or build your own fog light harness) even though it's far more popular to swap over to the 97-00 bumper and get OEM or aftermarket 97+ style fog lamps. Especially for the times that fog descends on those higher altitude roads this can really become a necessary added safety feature.

KahnBB6

iTrader: (5)

Also, babycrab, if you are in the L.A. area or thereabouts and you need workspace to do some big jobs on your car (although an engine swap would be a tall order without a home garage) I recommend Your Dream Garage in Baldwin Park (Google them). Their website explains everything and they're pretty reasonable to rent shop and life time from. Excellent place to do a specific job on your SC that is made so much easier with a lift. Also if you happen to live in an apartment complex that makes it very difficult to do much work on your car.

RudysSC

Sounds like the start to an awesome project and a sleeper to be reckoned with. Can't wait to see more!

babycrab

thanks, I agree it's a great canvas to start from. it already checks some of the boxes I appreciate in cars; black paint, tan leather, silver wheels. also no cd changer or heated seats, both of which I wouldn't use anyway.

good find on Gentex. the fact that the oem for the sc's rear view is the same oem Lexus is currently using to manufacture their modern rear views makes the project less daunting, and likely more satisfying when done, knowing Lexus use them today.

since the motor work will come much later down the line, I am ignoring gauge placement for now, as I am not looking forward to having gauges outside of the instrument cluster. goes against the vision I have for the car

I was thinking of having the bottom bolsters on the factory seats puffed up to limit slipping around. I love the shape of the factory seats, especially the fat headrests, moreso than the supra seats. If a pair of good condition supra seats pop up around my area for cheap, I'll probably get them, but that's unlikely to happen. I was considering a smaller steering wheel from the toyotas you mentioned, although I'd likely have it reupholstered in tan.

improved low beams are on my list, I've never worked with hid lights however, and in the past have been put off by the extra modules they require.

my eyes arent the best, so I benefit from the extra visibility the cornering lights give me on turns, and would choose them over front facing fog lights any day of the week, considering I very rarely encounter fog.

thanks for the pointer, I am a bit south from Los Angeles, though. I plan on doing as much as I can from home. thankfully I have family locally with a mostly open garage I can work in/park in (that's where the car currently sits).

thanks Rudy

babycrab

deleted for clutter

Bimmerbill

Just found this thread and what great directional information to start an SC project with. Good luck, I look forward to the progress and for sure I am subscribed.