bron_karr

I figure I will start my own build thread on here, considering the fact that a large part of my knowledge on this car is from other build threads on here (especially jimmymac's).
After searching for 9-10 months for a 5 speed SC, I concluded that if I found the right auto, I'd buy it and swap it. I found mine in north Oregon for 7500. Black on black, fully stock and nearly mint. I called the guy as soon as possible and drove down from Seattle to pick it up.
All I've done since then is an oil change, ebrake boot replacement, waxed it a few times and cleaned the crap out of the interior. I have huge plans for this thing, and I would like to keep it forever, but it's gonna take a long time since I am still in HS.
My build plans:
R154 swap (ordered all the parts for this yesterday)
1jzgte vvti swap
Upgraded twin turbos
400-500whp on 93 (I still would like to daily it)
7500-8000 rpm rev limiter
Airlift and some decent wheels
I would also like to fully reupholster the interior and fully respray the car black
My goal is a very daily-able, fun, luxurious car that pays homage to toyota's vision


This is before I got a new ebrake boot

Tallyhoe

Nice car, looking forward to your project, will not be an overnight thing, but a constant build.

Rcreegan

iTrader: (2)

Clean car! Best of luck. Few words of advice are to knock out all of the maintenance stuff first, learn the ins and outs of writing, and buy wiring diagrams and or Lexus manual.

bron_karr

Thanks guys! I figure I'll do things a little bit at a time. Stage 1 would just be to clean it up and get it running perfectly with some nice wheels, suspension, and the new transmission (gonna be my first manual car). I figure any engine work will be done after I finish college and get myself a new daily (hopefully a Tacoma). I'm slowly starting to realize just how much wiring work I am going to need to do. Btw rcreegan, I read your whole thread and love the build! My first car was a second gen GS300 and I loved that thing to death.

KahnBB6

iTrader: (5)

Very nice find!! It looks very clean inside and out!

And yes, JimmyMac's excellent work on his car has been inspiring to us all!

Being a late model with VVT-i you will indeed have a slightly easier job if installing any GTE VVT-i engine. Personally a 1JZ-GTE VVT-i was my own first choice in a swap engine as well but I didn't go that route for a few key reasons.... however with few to no restrictions that would have been my primary engine choice as well due to the nice high revving nature of the 1JZ.

Being a 1JZ-GTE VVT-i there is actually only one turbo: the Toyota CT15B. It is the earlier version 1JZ-GTE Non-VVT-i which came with factory parallel (non sequential) twin turbos. There are high flow upgrades for those turbo housings using steel wheels and there are many single kits for the 1JZ Non-VVT engines.

For the 1JZ-GTE VVT-i there are upgrades available for the CT15B to flow better for higher power and there are a few good aftermarket turbo alternatives. A nice high end full turbo upgrade is the Tomei Arms M8280 turbo kit which is pretty much bolt-on as a whole system. This would get you pretty much at your desired horsepower goals.

When you finally do swap to the 1JZ-GTE VVT-i it is advisable to either switch to the stock Soarer 1JZ-GTE 5-speed's 4.083:1 final drive ratio (get one from a GS300, MKIV NA or SC300 5-speed) or SC400 3.916:1 final drive. An LSD is highly recommended when you go turbo to more efficiently put power down.

You'll probably find a 1JZ which originally came in a front sump application so you will need to swap on a rear sump upper and lower oil pan from an SC/MKIV/Soarer (either from your original engine or as individual used parts).

...

I think I also must have spoken to you about how to re-use your SC300 Auto front driveshaft to have it modified for R154 compatibility (send it out to a driveline shop to have it lengthened approximately +50mm/1.96" and then have it re-balanced, possibly with your rear d/s on the balancing machine). This is a very strong and good option which can more than handle your desired power goal.

Also, while you will not need any extra cooling capability right now while your car is naturally aspirated there is also no harm in pre-planning your cooling system upgrades for the turbo engine swap even to just have the parts needed set aside for now. A Koyo aluminum radiator for MKIV's is a go-to first step (not needed right now but will be needed later) and you should also get a fan shroud that allows for the single or dual auxiliary cooling fans to be fitted. If you look in my build thread you can see how to fully recreate the Supra MKIV TT and Soarer 1JZ-GTE style aux fan relay control circuit (which uses both a separate coolant "switch" and an A/C refrigerant pressure "switch" to activate the fans with relays)... or you can use an aftermarket aux fan controller unit (Mishimoto usually, rated up to 20A of current draw) for the small amount of current that those pancake aux OEM cooling fans run.

^^ I mention things like this to you now so that you are aware and can plan early for what you will need later.

.....

For now, as suggested above, just focus on the regular engine maintenance and your 5-speed swap for now. It will still give you a great driving experience just from having switched to a manual transmission and will keep your overall costs down. While still in school definitely don't let the costs get away from you. Very good plan to keep things simple until you're out of college

SC's done right and cleanly can be deceptively expensive endeavors but taking that approach to it and not rushing will give you the best results. Also you will be surprised by just how many steps, parts and mini projects are needed to achieve just what you have laid out in your main post. So with that being said, collect some key and critical parts here and there as you go yes ... but otherwise keep the big project plans in the background for now.

Your goals are not super complicated from the sound of it which makes the long term of your project very attainable. It will just take some time, patience and diligence but it sounds like you are already well into researching and planning your roadmap

Your SC is a beautiful example you have found!! Definitely a keeper car for the long term!

Also, yes, there will be some wiring work needed. Mostly to the engine harness (which you can learn how to do yourself or have farmed out to one of a handful of professional harness makers) but also for some individual circuits you will need to change or add to the car at the time the 1JZ-GTE engine will go in. But take things one step at a time. You have plenty of time to take it easy.

bron_karr

Ah crap I forgot it was single turbo. I guess I don't necessarily want twin-turbo, but something that can mimic the smooth power delivery of that setup. That's the theme that I seem to find with every review of a stock twin turbo supra or soarer.

Would it be beneficial for me to convert to twin-turbo, or are modern single or twin scroll turbos good enough to mimic this?

I definitely am considering lsd options. It seems that my best bet is the os giken.

That driveshaft trick is going to save me a decent chunk of money and time! Thanks for that previous tip. One thing I have heard is that the two-piece driveshaft will rattle a bit with high-horsepower applications. Are my power goals going to encroach on that territory?

Looking at other builds on here, some passing 10 years, I am starting to understand the amount of time I am going to invest into this thing to do it right. I am super excited for the challenge!

I hope to own this one for life, and maybe pick up a few more 90s lexus/toyotas along the way!

Thanks for the support!

RudysSC

Beautiful car man! What an awesome way to start your journey into cars. You'll find a plethora of knowledge and builds about this chassis here that'll definitely help guide you along the way! Keep things simple and enjoy the journey. Get that thing up to spec in the maintenance department and from there a manual swap, some bolt ons, and an LSD will make you fall in love with it way before you go through with a big turbo, bags, etc.

Best of luck friend!

Barbary

Great way to start out w cars, interior looks fine to me

ThomasGS4

iTrader: (19)

Congrats on the buy, looking forward to the build!

bron_karr

Yeah I guess I'm a perfectionist. There are a few little rips in the back seats and I would hate to only reupholster the back ones

Rcreegan

iTrader: (2)

feel free to shoot me a pm if you have any questions bud! On here a few times a week but always willing to loan some knowledge

KahnBB6

iTrader: (5)

Well all four stock GTE engines have slightly different character... in stock form.

1) The 2JZ-GTE Non-VVT-i with the stock sequential turbo system working is a very early 90's old world high tech way of delivering excellent engine response within the confines of the OEM turbocharger technology of the era. Boost comes on almost immediately (with 80% full torque by 1,800 RPM) with all power routed through the #1 turbo as controlled by the #1 turbo waste-gate. Transition begins at 3500RPM and both turbos are online by 4200 RPM. When disabling sequential mode and putting the engine into TTC (True Twin Conversion) both CT12B (USDM/UK/EURO) or CT20 (JDM) twin turbos spool up in parallel through all six ports into BOTH turbos like a 1JZ-GTE Non-VVT-i and there is much more lag until around 4,000RPM. Modern single turbos aren't 100% the same super low down response character as is the stock sequential twin system but the most modern single setups can come very close with superior flow characteristics.

However so long as your stock twin system is actually working well and is healthy it's an excellent and easy to drive high response factory stock turbo system.

2) The 2JZ-GTE VVT-i is everything as described above only with the benefit of slightly better efficiency and slightly better low down torque thanks to application of Variable Valve Timing With Intelligence on the intake cam.

3) The 1JZ-GTE Non-VVT-i is an over-square high revving engine. It has less low end torque due to less displacement and the different stoke but it loves to rev. I haven't experienced them myself but the twin CT12A's start to come into their ideal boost range by 4000RPM or so (I think?) and the the power remains strong from there. Below 3,000 RPM the boost isn't strong (stock). But it's a fun engine. You can upgrade those twins for a nice BPU parallel twin setup or you can switch to a single. This also explains why the 1JZ Auto models got a 3.92:1 final drive ratio and why the 1JZ 5-speed manual models got a 4.08 final drive ratio.

4) The 1JZ-GTE VVT-i is the same as above in #3 but with the addition of VVT-i on the intake cam and the very improved factory single turbo setup there is said to be a completely different and ample delivery of low end torque and strong midrange torque. In 100% stock form the CT15B turbo is said to begin to drop off a bit in the much higher rev ranges... meaning its efficiency over the previous parallel twins was primarily chosen to greatly improve low end power and midrange power. But if you get that CT15B housing upgraded or if you switch to another bolt-on turbo like the Tomei Arms M8280 you can overcome that limitation.

According to an older article on the Australian based AutoSpeed website (available now only via the WayBack Machine) the 1JZ-GTE VVT-i Soarer 5-speed in stock form comes closer (but is not totally equal to) the response of a 2JZ-GTE sequential twin turbo engine:

https://web.archive.org/web/20120327...7/article.html


Here are a couple of their articles comparing the JZ engines:

https://www.autospeed.com/cms/a_2750/article.html

http://www.insiders.co.uk/soarer/review/index.html

https://web.archive.org/web/20040805...0/article.html

https://web.archive.org/web/20040805...7/article.html



A 1JZ-GTE Non-VVT-i with its stock twin turbochargers (parallel spooling) is best to do a high flow upgrade to them or go single.

A 1JZ-GTE VVT-i with the stock single turbo... single turbo in any configuration is the way to go. It is a very good setup out of the box and will only need a high flow upgrade or upgrade to a bolt-on 1JZ VVT-i specific aftermarket turbo to raise the available power ceiling capacity. It is not beneficial to try to do any custom twin turbo with today's available superior single turbo technology and the OEM twin turbos from the early 1JZ-GTE and 2JZ-GTE will not fit anyway. You would need to swap over the entire cylinder head from each in order to fit them and then do some custom oil line plumbing to lubricate them... and in the case of the sequential twin turbochargers from a 2JZ-GTE you need specific control programming from their stock ECUs or from a couple of aftermarket standalone ECUs (Link G4X custom programmed or VIPEC custom programmed) to get the sequential system working correctly.

A 2JZ-GE... this will also only be something you should make into a single turbo setup. Technically you could fit 1JZ-GTE Non-VVT-i parallel twin turbos with the 1JZ Non-VVT head and it would be the same for fitting a 2JZ-GTE head... but again there is the issue of plumbing the stock oil feeds for each of these systems which are really set up as needed on 1JZ-GTE and 2JZ-GTE short blocks rather than 2JZ-GE short blocks. I considered all this at one point myself before realizing the added complication and so I just decided to go with a 2JZ-GTE short block and 2JZ-GTE Non-VVT-i cylinder head for my 2JZ-GTE sequential twin turbos.

The response of stock 2JZ-GTE sequential twin turbos in CT12B or CT20 format is very good when the system is working well with no issues. But it is also a complicated system which isn't totally easy to diagnose to which I can attest. Also while you can do 450-500whp with them it's better for their longevity to consider the GT28 Hybrid (USDM/UK/EURO) or Mitsubishi cartridge Hybrid (JDM) STU / BNR Supercars and other big JZ aftermarket companies to raise the capabilities of the stock housings to handle much more boost safely up to a max of around 700whp in high boost modes.

But MOST people who are looking for big horsepower beyond just BPU specs with a 1JZ-GTE Non-VVT-i twin turbo or any 2JZ-GTE will consider modern, superior and much simpler single turbo setups.

These are very good systems. I like mine (sequential twins). But it's kind of the inverse of what you are suggesting: reasons to STAY with factory twin turbos that already came on the engine.

These reasons can be (but are not limited to):

1) Keeping things simple and relatively affordable by staying with the stock/OEM turbo system.
2) Local emissions rules requirements in your area (many parts of Europe for instance and California for USDM 2JZ-GTE engines. I built mine specifically to meet all California emissions requirements as my #1 consideration... which meant keeping an all-stock USDM 2JZ-GTE).
3) You just want to stay with the stock system to keep the GTE engine as close to its classic original configuration as possible for the purposes of preserving the classic experience.


There are some totally custom twin turbo parallel setups which some people have done in the past but I think the benefits of this really come down to what the flow, size and response advantages are with the two turbochargers chosen versus the flow, size and response characteristics of a single turbo setup on the same engine.

If you are mainly focused on the response of the 2JZ-GTE stock sequential twin turbocharger system then I would say you would want to start with a 2JZ-GTE stock engine rather than trying to custom install that same system onto another engine.

Take note that there are only a small handful of performance cars in the world which ever got *sequential* twin turbocharger setups from the factory. All of these were developed to overcome the limitations of turbocharger response and flow technology at the time they were originally designed. Turbocharger technology has come a long way since that time.

1986-1993 Porsche 959
1992-2002 (Worldwide, not just USA) Toyota Supra MKIV Twin Turbo and Toyota Aristo Twin Turbo
1992-2002 (Worldwide, not just USA) Mazda RX-7 FD3S Twin Turbo
1993-1998 Subaru Legacy Twin Turbo

Many other twin turbo cars exist but they haven't been sequential twin turbo because turbo technology and other technologies just made such a complicated system unnecessary from that point on.

Some exceptions with aftermarket parallel twin turbo systems on inline-six engines are usually done (at greater expense) with cars that came with twin turbochargers originally.

The Nissan RB26DETT is one example. It is a high revving 2.6L which did come with factory twin turbochargers but these were parallel spool not sequential. Some aftermarket setups for them use a higher flowing manifold and higher flowing set of much more modern turbos but still they are not sequential. And some RB26 engines are also set up with a single turbo. It depends on preference.

Some BMW inline-six engines are twin turbo from the factory but all (to the best of my knowledge) are parallel spool, not sequential. I am not sure what the aftermarket twin parallel turbo setups look like on those engines but the cost is very high whatever they are.

Finally there are some 2JZ-GTE's that I have seen with aftermarket parallel spool twin turbo setups but often these are somewhat rare for people to install. I think there must be a noted difference in response with such setups over a modern single turbo setup but they are more complex and more tightly packaged. It is an expensive endeavor when it is implemented on a 2JZ-GTE.


The OS Giken 1.5-Way Super Lock LSD is the very best for street and track. Superior in all respects. For dedicated track drift cars a 2-Way aftermarket LSD is usually better.

Kaaz makes a "quiet" 1.5-Way aftermarket LSD for our differentials as well.

The old OEM Toyota Torsen T-1 200mm worm and spur gear type LSD is a good option for mild applications. I have one of those and it has served me well for NA duty and my mild 340hp-ish stock GTE engine. However it needs to be used with good tires and can snap suddenly to the left in the wet (or if your tires are temporarily wet before drying off) under power which can catch you off guard if you're not careful. I've had that happen a few times but know it well enough to avoid it now. However once you start putting 450whp+ through them they also lose their predictability and will eventually be on borrowed time. People's experiences with them may vary. Good for mild street cars if you score a deal on one. Otherwise they last a LONG time and are generally very tough so long as you don't expect them to do really high horsepower service with predictable results (just due to how they are designed and deliver torque biasing through their gears).

For your purposes with your horsepower goal in mind I would skip the Torsen T-1 LSD and look at the other LSD options available to you. It is a good older LSD but not ideal for every single application.

The very rare OEM Toyota Torsen T-2 200mm is better than the older one and is the same style design that Toyota uses in their modern GT86, GR86, GR Yaris, GR Corolla, GRMN cars and in some Lexus performance models. In the SC-compatible 200mm diff housing version that we can use it responds more predictably in those wet situations and can handle more ultimate power than the older T-1 version. It showed up in some later model Supra MKIV TT Autos, some super rare late model Supra MKIV NAs, later model JDM Supra MKIVs, later model Toyota Soarer Z30's and in later model Aristo V300/3.0V factory 2JZ-GTE models. VERY rare to locate one used.


This should not be an issue, no. As long as your rear donut between the differential companion flange and rear driveshaft is good (not cracked and compromised needing OEM replacement) and so long as your OEM center bearing is in good shape and needs no replacement then the factory two-piece driveshaft system will be good for a LOT of horsepower and torque somewhere just below four digits.

You will not come anywhere close to overwhelming it with the goal of a mere 500whp.

It is true what you have observed by reading and learning from other builds here. Even if you have no constraints with money to fund the project things can still take time and problem solving efforts to put together the best and/or right way. Sometimes parts take a while to get. Sometimes we collect parts for later mini projects over a long period of time only to be finally ready to execute those mini projects when all the parts that will be needed are right in front of us.

Challenges are good and they force us to learn new things and become better skilled through each endeavor! As project vehicles go this is a very good one to use as your basis. It is not as cheap to set up with all the most desirable equipment as some other platforms are but it has tremendous support from the aftermarket and owner communities. It is an excellent all around vehicle combining very good handling with luxury GT characteristics and a chassis that can handle Japanese musclecar style characteristics.

If it's a keeper car for you over the long haul then it will be an excellent classic machine to keep with you and turn into what you wish it to be

bron_karr

Okay, so everything arrived today. Calling a local driveshaft shop today to talk about extending my auto shaft's spline. After that all I need is flywheel bolts and a day or two. It's probably going to happen around the 13th of April cause I'm kinda busy unfortunately. But man, is it cool to see everything in one place.


fdsdfs

RudysSC

Looks awesome - I'm sure jealous of that nice new R154. Sometimes I giggle to myself about my poor old W58 hangin in there like a true champion lol.

KahnBB6

iTrader: (5)

Very nice!!! It's always cool to see a new manual swap project come together!

You may need to buy the rear dust shield part separately for that R154. It's a cheap thick steel part that has to be uniformly and evenly pounded onto the rear of the transmission with a block of wood and a hammer. It will come from Toyota unpainted so the outside section should be painted by you or be given a cheap black gloss powder-coat to protect its metal over time.

With that transmission out of the car for now you will be able to experimentally insert the spline end of your SC300 A/T front driveshaft and see for yourself how it's the same pattern for a perfect fit. It's just too short. The extension should be +50mm (+1.96") approximately. No more, no less. It's okay if it ends up a millimeter or two off just so long as it isn't longer than +50mm more length. A good driveline shop should be able to get the lengthening measurement spot on. Then have it rebalanced of course. And then repaint it in a fresh coat of black.

The re-balancing of the front driveshaft may require bringing your center bearing and rear driveshaft to them as well. But the rear should not need new weights, just the front. Ultimately let the driveline shop get the whole modified driveshaft system balanced well for you. It should be just like stock when done and installed: Invisible to you. IE: you know a driveshaft is there under the car but it is neither felt nor heard.

I see you got the MKIV clutch pedal and box and the MKIII Supra R154 factory clutch. That is such a light and easy clutch kit to drive with!