Nick, I am glad you finally revealed your plan for the SC! Ambitious, yes. Uncommon, very. Bold, absolutely. Bonkers in all the right ways, you bet!

You've got a lot of work ahead of you with this project but I think having a good plan to set the tone and goals is a fine way to start. I also did this ahead of things when I started my CA-legal 2JZ-GTE swap build. It was itself a 5-year project to get 95% completed with the rest and final restoration stages ongoing.

I am aware of the stout design of the 1GZ engine but I am not aware of how well it responds to a fully custom NA build. Some engine such as the GM LS or Ford Coyote respond very well to naturally aspirated tuning. The 1UZ doesn't seem to very much without introducing a supercharger or turbochargers. I am not sure if the 1GZ will respond similarly to how the 1UZ does in that regard since you want to make 500-600hp (or is it whp?).

Even with a 12.5:1 compression ratio, custom cams and other big changes this may still prove to be a challenge. The official horsepower rating is "276hp" but it reportedly produces about 308hp in stock form. Going up another 200hp let alone 300hp on 93 octane pump gas is a big jump. I realize that a turbocharger on each side of the engine goes against the naturally aspirated focus that you want it to have.

It makes me curious as to whether or not any Japanese company has ever developed a stroker kit for the 1GZ to give it more than the standard 5.0L displacement.

I don't know this for a fact but the old rumor was that Toyota engineers developed the 1GZ-FE by combining two 2.5L 1JZ-GE engines to create a single 5.0L V12. If this is true it would be extremely similar to the development process that BMW used for the 8-Series V12 engine back in the very late 1980's.

Are you considering ITBs for this build or are you planning on going with a more conventional fuel injection system hooked up to a modern aftermarket ECU?

For the fuel system upgrade you may well be able to get away with using a high flowing Supra TT Denso fuel pump and the 12V w/Relay Mod and 10ga direct battery fuel feed in order to get it wired up. This would allow the use of your stock fuel ECU for safety shutoff and control without being limited to how many amps it can flow through its circuitry to the pump itself. Your stock fuel system and tank is a return type system so that makes it all the more easy to adapt to the new engine's fuel system.

You didn't mention anything regarding brakes and other than the basic go-to 1995-2000 LS400 front brake caliper upgrade you could go with MKIV TT brakes at all four corners (which gives you much better pad selection for track use... although yours will be a street car). Then there are a range of other front brake options with six piston calipers.

See my comments in my last reply above regarding the Supra MKIV rear subframe swap pros and cons. If you are very set on this, go onto Supraforums and look into the "Lance Alignment" which mostly works on SC's but which is perfectly matched on MKIV's. Keep in mind that the MKIV is still a slightly lighter car and that is has a slightly shorter wheelbase. Both the SC/Soarer and MKIV were engineered for high speed stability but I do wonder if the wheelbase difference has anything additional to do with the reasons for the MKIV rear subframe having some geometry differences compared to the SC/Soarer.

A Supra rear subframe swap is usually done in order to get the TT 6-speed's 220mm Big Diff which only comes in a 3.133, 3.266 or ultra-rare Euro-only 3.5xx ratio. The 200mm diff in the SC/Soarer/MKIV non-6-speed is more than stout enough to handle anything you want to throw at it with this project.

...

The hood, if you will be going with a CF example, I think isn't going to be the best all-rounder if you choose a vented style. I looked into this myself earlier this summer because I was experiencing some major under-hood temperatures during a heat-wave and on one occasion had to pop the hood and let the engine and cooling fans go at full tilt while in a covered parking garage for a few minutes until my aftermarket coolant temp gauge dropped to an acceptable reading.

This is with stock twin turbos, a stock side mount intercooler that doesn't block my Koyo TT radiator's airflow at all, a stock mechanical engine fan and three factory Supra TT auxiliary electric fans.

So I began researching vented CF and fiberglass hoods for MKIV's (because MKIV owners tend to do this more than SC owners). The consensus tended to be that while some Supra owners go with the vented hoods and while, yes, they can help, they become a problem once the weather changes and it begins to rain on you. This is not an issue for areas that see little or infrequent rainfall such as southern California but in Florida for instance it goes from blazing sunny to torrential downpour very rapidly.

Therefore I abandoned that plan and stuck with the factory non-vented hood design. As it turns out it was a truly abnormal heatwave that I was experiencing at that time and since then I have found that my cooling system is VERY up to the job. Even during the heatwave the cooling system was dialed in enough to keep the engine temperature well in check. It was just hotter on average than I was used to.

For a naturally aspirated SC with far less under-hood temperature since there will be no turbochargers to generate extra heat and heat-soak everything I don't think a vented hood will be necessary.

.....

I love all the other details you plan to give this car!

I would say focus on the suspension, engine, transmission and other major changes before moving into finishing and body/interior perfect phases of this build project. It will be better to get those out of the way first so that the guts of the car have been sorted out.

 

I love your engine choice and excited to see how you take it.

It can be done NA, turbo, or supercharged to meet your goals. Check out some examples I found.

Jaron Olivecrona’s 1GZ-FE V12: CNC ported heads, custom cams, larger valves, and custom 13.5:1 compression pistons dynod @ 700-800 hp @ 9500 rpm
https://engineswapdepot.com/?p=21650



some nice turbo examples:

 

I agree. The bolstering is the main issue, but I also want that racing seat look as well!

To clarify about the CF, I do not have any intentions on using CF doors. Only the hood and trunk. The door cards will be redone completely, to accommodate the speakers and some subtle design changes.


Because the hood will be vented, I don't think I'll have any issues at high speed. The vents turn the engine bay into a low pressure area, which should eliminate any danger from the hood flying up on me. To your point, I don't know how many 160+ MPH runs I will do, though maxxing the car out would be something I'd like to do one day!


Yeah, I also considered the GTO. My friend has an '05 with the LS2 6.0L and it's turbocharged. He warned me away though with access to parts a little shoddy and the car in general isn't built like a Lexus. Besides, I had always kind of wanted an SC. When it's all said and done, if I can have the car hovering around 3,500 pounds I'll be a happy camper!


Yeah, you bring up some good points. I really don't know exactly what goes into the change in suspension geometry. Could it simply be that because the wheelbase is shorter, that the arms are shorter? The rear shocks are shorter too, perhaps this is the reason? This will definitely require a lot more research on my end, but my initial feeling was that I could see some big improvements in the sharpness of the car with this change. Perhaps because I'm sticking with an SC coilover I should avoid the Supra subframe? This will need more sussing out.


There are several examples of all motor builds with lots of horsepower, but they're typically race engines. I don't have $50k to spend on the engine alone. Just looking at some factory engines as reference, I think that 100-120 horsepower per liter isn't too far fetched. I already mentioned the Voodoo which is 526 horsepower from a 5.2L. The standard Coyote is a 5.0L and makes 480 horsepower in the Bullit Mustang. Looking back at other engines, such as the F20 from the S2000, I think it's doable. It's not lost on me that this won't be easy, but I think it's attainable given the large displacement of the engine and tuning capabilities of today's standalone computers.

As for the engine, I haven't seen any stroker kits. Overbore options are limited. I've spoken to some guys in Australia who say the maximum overbore is 1mm without sleeving the block and I do not have any desire to sleeve the block and open up all those potential pitfalls. I'm also not that interested in a longer rod because I want the engine to rev freely. I don't like low RPM torque monsters nearly as much as a "high revving" engine. It could work, but I'm just not looking for that end result.

It is a misnomer that the engine is two 1JZs put together. In fact, the 1GZ doesn't share the bore or stroke. It also is an all-alloy engine. The 1GZ-FE weighs about what a 2JZ-GTE weighs; ~600 pounds.


I agree. I had that same setup on my RX-7.


My initial plan is to use LS460 calipers in the front and perhaps the rear. I am not totally sure if the rears will work for me, as they are mounted radially. But, the kit is sold by XAT and specifies use of IS-F front rotors at 14.2". Many will recommend the TT brakes because they're proven track reliable and have tons of pad choices, but I will not track this car. I would much prefer the weight savings of the all aluminum LS460 calipers and size/bling factor. When it comes to brakes, I'm less concerned with performance, because I will only need them to stop me one good time. LS460 calipers with 14.2" rotors will do that just fine.

I am concerned though, that they won't fit under my wheels without spacers. We'll just have to wait and see on that.


I plan to only add the vents in the hood if I can fashion rain guards which I can relatively easily install and uninstall. I won't drive the car in inclimate weather, but to your point there is no avoiding it sometimes. I am not going to be using virtually any polished or chrome bits under the hood either, so if it were to get caught in the rain, it shouldn't be a catastrophe. Just clean it up and dry it off.

Part of the reason I want the vents is to lower underhood temperatures, yes, but also for a little bit of show. Remember I am trying to recreate a car as it would have been made by an OEM. Most upgraded "performance" versions of a car have a few outside clues to their performance. M cars have fender vents, so do F cars for that matter, and I think that vents on the hood would make sense to denote a more performance oriented SC. I'd love a slight power bulge to go with it, but I haven't seen any hoods with this design. Clearance for the engine is a bit of a concern as it relates to the hood, as our hoods are slightly lower than Supra's. We'll see if maybe I can incorporate a power bulge and free up some space under the hood.


Yeah, I agree. I've already purchased my coilovers and will focus on just getting the car running like new, for now. After this initial stage, I'll buy the engine and put it on a stand for a year or two while I accumulate parts. Take it to the machine shop to have the bottom end and heads built, then I'll assemble the longblock. To your point, the interior will probably be last because I've already got the "desirable" interior, so why rush it, right?


I've seen that Silvia. It was built by Hartley engines, I believe. That's the $50k engine I reference before. It also revs to 9500 RPM, so I won't be needing/wanting that. But, I appreciate where you're coming from and I think you're right. I think I can get to 500 horsepower or thereabouts without going off the proverbial deep end.

Nick

 

Dang it.... the forum just ate the response that I typed up.

I can't go into that detail again right now but to briefly hit on two points:

Look up the Gixxer_Drew Suspension Thread on Supraforums: https://www.supraforums.com/threads/...thread.446817/

The designer of that DIY suspension for the MKIV and Supra, Andrew Brilliant, goes into a lot of detail about the MKIV and SC/Soarer Z30 suspension designs in his quest to build the best bang for the buck versatile street/track suspension for both platforms. He actually developed it on his SC rather than on an MKIV Supra... and he actually preferred the higher chassis rigidity of the SC/Soarer over that of the Supra MKIV and had some specific thoughts on the suspension geometry (but it is a very long thread).

Here are some more recent links about him. Unfortunately for the SC/Supra community he all but moved on to larger professional racing projects several years back. However his knowledge of the platform's chassis architecture is still contained in that thread and in a couple of others on SupraForums.

I installed his suspension into my SC300 in 2011 and I'm still running it today.

https://worldtimeattack.com/index.ph...rew-brilliant/



Also the LS460 front brakes should be just fine for this application if they will fit. Very strong braking package.

For the hood you have in mind, have you considered NACA ducts placed carefully in areas on the hood which would best draw in air to the hottest areas so as to better promote cooling. They would be very easy to design removable block-off plates for (out of CF or whatever you wish) with a gasket on them to seal out rain.

 

Dude, I HATE when I lose a long response! You must have been fuming. Thanks for still replying.

I will task myself with reading that entire thread sometime soon. Got stuff going on now but I’ll get to it. It sounds like exactly what I’m looking for. Thanks a ton Craig!

As for NACA ducts, I’m familiar with them. I know how efficient they are but I’ve always viewed them as a hardcore option cause they’re so ugly! I don’t anticipate the heat being a huge problem to be honest and the my intent with the hood vents would be to promote better airflow through the front of the car and allow heat to radiate out at a stop. That’s about it.

The look is more important to me than they’re maximum efficiency, for this mod anyway. A NACA duct would run counter to my design goals as it’s all function and no aesthetic. I am all for maximum performance, but not at the expense of aesthetic or comfort. Again, taking the view of an OEM, how would Toyota re-design the car with today’s materials and electronics and styles?

I was thinking of using this:


Advan Carbon modular hood vents

I found Advan Carbon while reading other threads here and found that they will do custom hoods for you. I was thinking of asking them to add these vents which they also make, into my hood with no rivets or screws for a cleaner look. I want them cut in and resin’d with the hood. I would then paint the hood RSP but leave the vents carbon fiber. Similar to this:


Aston Martin V12 Vantage S

You see where I’m going with this, right? Our hoods are nice and flat too, so it shouldn’t be difficult to fit those vents in there.

I plan to approach them on integrating some kind of power bulge as well, but I think that’s where they’ll tell me no. Too expensive and too difficult for a one off.

Nick

 

Reading into the gixxer_drew thread a little, his approach runs so counter to every manufacturer of aftermarket coilovers. I see the logic, but then why is every one of these coilover manufacturers running such stiffer springs?

I also wonder if there’s a correlation to stroke length and spring stiffness. For example, does the longer stroke of an SC coilover compensate for a stiffer spring? Perhaps the ride quality (comfort) of a shorter stroke Supra coilover with a softer spring, is similar to a longer stroke SC coil with stiffer springs?

I’m just struggling to come to grips with the fact that he’s recommending 250/500 lb/in springs and my Müller coilovers, which are a “luxury” coilover with ride quality placed as a high priority, uses 8/12 kg/mm springs. Converting the lbs to kgs, that would be 4.5/9 kg/mm. That’s quite a bit softer. It makes me question my spec.

I spoke with Fortune Auto before placing my order and they recommended increasing the spring rates because the 8/12 kg setup was for the lighter SC300. They went on to explain that because I had the heavier SC400 and larger, wider wheels with stickier tires, that I should use a stiffer spring. So, it was spec’d at 10/14 kg/mm. Now, these coilovers are totally custom built to order, so I’m wondering if maybe I should have done a much softer setup?

I wish I would have read this thread before I pulled the trigger cause now I’m questioning it. The ironic thing is, I was looking for a set of used Bilstein dampers from a JDM Supra RZ and was really close to doing it but I wasn’t sure if they could be rebuilt and I didn’t want to start off with the first mod on my car being a mistake. If I went with a gixxer_drew setup, I could budget out my big brake kit with these initial modifications.

Craig, tell me please how you’d describe your ride quality on your SC. How does the comfort compare to stock? How low are you?

Thanks.

Nick

 

Nick,

It definitely sucks when you've written a lot and forgot to copy your full text to the clipboard JUST in case the "token" has expired by leaving the page open for too long (such as several hours or a day). It happens to us all once in a while.

I have to respectfully disagree with you on NACA ducts The R34 Skyline GT-R's incorporated one into their hoods to cool the turbos and it was rather brutalist-elegant in my opinion like the rest of that car. Perhaps the entire R34 GT-R is an acquired taste but I've always liked how blunt they are aesthetically. The Lamborghini Espada also famously used NACA ducts as did the 1969-70 Shelby Mustang GT350/500. So did the rather cool looking 1991-1992 Isuzu Impulse RS (1.6L turbo AWD rally car) with its single offset NACA hood scoop feeding its top mount intercooler (aside, I almost bought one of those in pristine original condition with only 50k miles. I couldn't swing it at the time and I'm still kicking myself for missing that one).

I have long considered adding a single paint-matched NACA duct to my SC's hood on the turbo side. What has stopped me is not having a clear idea of how the R34 Skyline's hood ducting worked and how it diverted rainwater away from the engine or if it has any sort of removable block-off. If there is such a setup on the Nissan I would want to recreate it on the SC's hood.

However these cars do very well in general without any hood venting so it absolutely does come down to the aesthetic *you* are looking for

I'm very familiar with Advan's products. I think that's a good route to look into. The hood bulge as a one-off design shouldn't be so crazy. No more than adding carefully placed vents I'd think. Even so, what I'm seeing so far from the Motion.tv people is that they've managed to keep their new intake design well under the MKIV's stock hood limitations.

....

Regarding Andrew Brilliant's "Gixxer_Drew" suspension design ideas... I am in no way at all remotely as qualified as he is on suspension theory and aerodynamics... but from what I gathered several years back he felt that back in the very early 1990's shock absorber designs that OEMs generally could get their hands on for large volume mass production kind of... sucked in his opinion. So as he explained it, sometimes companies would compensate in other areas of the suspension. For the SC/Soarer and Supra this meant going with a four wheel true double-wishbone suspension. Interestingly he said something to the effect of the SC/Soarer not needing quite as much of a stiff spring rate as you might think because of the four wheel double wishbone design.

You picked up on this and are now questioning your coil-over specs and purchase. Well, hang on a moment with that. I don't think you made a bad decision. It really comes down to how the coilover designer views what a good ride is and what intended use they have in mind.

Brilliant (aka Gixxer_Drew @ SF for those reading who are unfamiliar with him) saw his approach as a budget-friendly but also street & light track capable suspension. He saw the four wheel double wishbone suspension in the SC/Soarer/MKIV as having some untapped potential (as does any aftermarket coilover design company) since Toyota was compensating for the not so wonderful shocks of 1990 when designing the suspension.

He never claimed that his roughly $900-$1,000 do-it-yourself coilover intended for near stock ride height only with stock geometry was better than the BEST coilover systems on the market.... just that the parts he had arranged were of very, very high level OEM quality with some perks such as revalving potential for custom track specs for those who needed it beyond what the stock Bilstein AK valving would provide. And the Hypercoil linear rate springs are similar of very high quality and different spring rates could be used as people wished.

Your question as to the longer stroke versus shorter stroke of the shock being a factor I think is very astute but unfortunately I'm not qualified enough to say either way on that.

.....

What I can say is that the Bilstein makes excellent shocks and the AK1242 and AK1243 were basically the same thing that Toyota's TRD division (old 90's TRD Japan) had available with their own branding as over-the-counter upgrades for Supra MKIV customers. Unfortunately just after I bought my own set Bilstein Germany for some reason changed either the height of the shock barrel or the height of the piston... and this caused people issues with needing to add helper springs in the rear in some cases. Actually I think mine does need helper springs to technically add 100% of the preload that should be there... but I just haven't yet installed the helper springs I have set aside for that fix yet. I actually don't know to this day whether or not I have the original AK design or the revised AK design in my car.

The solution is to send your used AK1242 & AK1243 shocks off to Bilstein with the correct specs needed to be changed BACK to the original design... which they can do for anyone who wants it.

As to the ride quality, I have been using the 600lb-in front & 325 lb-in rear Hypercoil linear-rate springs with my Bilstein AK shocks (which I bought brand new) for ten years now... and I really like the ride quality. I did buy the 500/250 springs a few years ago but I haven't installed them because whenever I am on good, well maintained roads I feel they are a perfect all-rounder combination for my 3600lb+ SC. I strongly considered the 500/250's in Los Angeles and for long distance trips because... well... some roads just aren't maintained well. Mulholland Drive in Los Angles and other similar twisty mountain roads are excellent regular driving roads... but in recent years they have not been kept up and this made me feel my otherwise ideal 600/325 springs (again, linear rate not progressive rate) were just a bit too stiff for the area.

Since I have been in Florida with the SC I have missed the interesting mountain roads but the highways and most roads are generally well maintained here and so I have been quite happy with the 600/325 spring combination.

Compared to the factory stock SC springs and shocks the Gixxer_Drew DIY coilovers are night and day different in all the right ways. It still feels the way it should as a "Lexus" but as a far more high performance Lexus that isn't catering to someone who is looking for a floaty hovercraft ride. It's slightly on the firm side but not at all bouncy. Control and turn-in are great and the control and response from the springs and shocks is excellent. On very technical mountain roads there is almost no body roll with the 600/325 springs but I also never ever feel like I am going to rattle my teeth out of my head either. It's just a very good combination for a street driven SC. The Supra TT Auto Torsen T-1 LSD and rear swaybar upgrade also helped in combination.

Unfortunately there aren't nearly as many long technical roads in Florida to exploit the improved suspension with but I can do highway cruiser duty just the same on this suspension.

There are much higher spring rate combinations that were tested with this DIY suspension but above 600/325 rates I think they're generally considered to be mostly for the track even though you can drive with them on the street. His suggestion for the 500/250 rates as being for "comfort-minded or Lexus ride quality" is.... probably accurate.... but personally I prefer the firmer 600/325 rates for the street.

Also to be fair when I first got my SC it was 100% stock but a number of things needed TLC or replacement. Among those were the brakes which I almost immediately upgraded to front MKIV TT brake calipers, the burned out clutch and the stock suspension which had blown shocks. The Gixxer suspension was one of the very first things that I upgraded on my car.

With the stock suspension I recall that the stock springs and shocks, despite being worn out, still had a decently soft but semi-sporty ride quality. But the level of chassis control in the Gixxer suspension wasn't there at all in the stock suspension. Stock there was a lot of body roll absorbing steering inputs. Also my steering rack bushings and front LCAs were both shot at that time so it's probably still not a fair comparison. When I first bought my SC300 it felt like I was driving a cool looking super floaty Toyota-Buick But I really loved how it felt even so and I knew that it could be greatly improved in every area.

I don't think you will be unhappy with your Muller coilovers. Both they and Fortune Auto know what they are doing and are probably only surpassed by Ohlins.

You probably have some degree of firmness adjustability with those coilovers as well by clicking a dial on top of each shock. This is something you cannot do on the fly with the DIY Gixxer suspension.

Have I been happy with my 600/325 Bilstein-Hypercoil setup? Yes. Only on truly terrible roads have I ever thought to myself "I really need the softer 500/250 springs installed". The ride quality is very good, not excessive or bouncy, provides very flat cornering and great predictable control. I should install the rear helper springs to fully cure the preload issue but it hasn't been an issue for me so I will just get to it when I get to it.

I am not sure how low I am but I checked the finger gaps the other day: four finger gap in the rear between the tire and fender lip.... and a three-finger gap between the front tire and front fender lip. My SC's ride height looks "OEM".... if the SC ever came with 17x8 front and 17x9.5 rims and 245/45-17 and 275/40-17 tires off the showroom floor.

I would do a fender wiring harness relocation and have a completely different suspension and possibly aftermarket control arms if I were to go lower than that. The Gixxer suspension just isn't designed to go low but I've always been fine with that.

Today I think you may need to track down used AK1242 and AK1243 shocks and get them reconditioned by Bilstein but the rest of the required parts should still be available. The rub is that the original price point advantage has been lost I think with the extra work required. It was supposed to compete at about a $900-$1,100 value but now it would be a bit more which gets into the territory of other aftermarket coilovers which are themselves good designs for the money.

The Gixxer setup is great if its limitations do not pose an issue for the SC or MKIV owner. In my case it was a perfect fit. In the future I may look into a different coilover setup but I'd probably be looking in the same territory you were recently with Muller, Fortune Auto... or maybe even Ohlins. But for me $1k in 2011 for great quality and some limitations was totally fine with me

But if I were looking right now even though I'd consider the Gixxer setup the availability of the shocks might give me pause. It's a setup that has worked so well for me for a decade with only street driving that I haven't had to focus on what a new coilover setup might be. But also keep in mind that in 2011 the coilover options that offered the same or higher levels of handling improvement and longevity were much more expensive than the $1k or less Gixxer setup. Value and quality for the cost was a big motivating factor for me at the time. But it has also remained a good investment IMO.

...

I will add that prior to owning my SC300 I owned a 2000 Honda Prelude Type SH. Also four wheel double-wishbone suspension front and rear despite being FWD. It had a kind of early torque vectoring system bolted onto the side of the manual transmission which gave it fairly neutral handling for a front-drive car. It would quite literally shove itself through turns based on yaw and steering angle among other inputs. But the stock shocks and springs were very good... but handling was FAR more improved once I upgraded the front and rear sway bars with thicker, stiffer aftermarket examples and notably upgraded to Koni Yellow shocks with H&R linear-rate springs on Ground Control coilover sleeves. The rates in the case of the 3,050lb front-drive Prelude the spring rates were 450lbs in the front and 325lbs in the rear. Not too stiff and not too soft but on the firmer side of "OEM-like".

I suppose my experience with the Prelude influenced my decision to do another DIY coilover setup in my SC300 since in both cases someone much more qualified in suspension theory and shock and spring combinations came up with the exact tiers that could be chosen from since each combination had been tested already.

Apologies if my reply is a little scatterbrained this morning but I hope this helps give you an idea of how the Gixxer suspension measures up.

 

OK, let’s settle this NACA duct debate right here, right now

We agree, that it looks good on certain cars. I think the cars you’ve mentioned all had an aggressive look to them and generally sharper lines than the SC. I guess I question their aesthetic with out curvaceous bodies. Your R34 example was convincing though, cause I love me an R34 GT-R!

Having said that, I think we can agree that my idea to use those long and slender vents will fit and flow nicely on our long and sleek hoods.

I appreciate your reply on the suspension cause I was beginning to feel like maybe I was making an all out mistake. Having said that, it seems like my spring rates may not be too far off. Your 600/325 setup translates to ~10.7/5.8 kg/mm. Our cars are about the same weight now, and when my 1GZ-FE swap is complete, probably about the same then. I probably will have the car a hair lower than you do though and my wheels/tires are a hair more aggressive. Add in the natural stroke increase for an SC coilover and perhaps I’ve got something here?

I tell you what. Let’s make it a point to take each other for a ride sometime in the near-medium distant future! Your description of the ride characteristics is honestly exactly what I was wanting with this setup. Like I said, the ride height may be the only thing I would want to change, slightly. So, I wonder if an opportunity did kind of pass me by. The coilovers are made to order, so I won’t be able to cancel or return them, I don’t think. Like you said though, hopefully the know how of Fortune and Müller shines through.

Where in Florida are you?

Nick

 

Nick,

We will have to arrange a meetup at some point, yes! That would give you a good first hand idea of what I am trying to describe to you.

I defer of course to your tastes and wishes for your vehicle because after all it is your canvas to get just how you want it The NACA ducts were only a suggestion of course but yes I do agree with you that the lines on all the cars I mentioned probably do support the NACA duct style far more than the constantly flowing lines on a 92-00 SC. The single offset NACA duct on the R34 GT-R hood right above the turbochargers is one of the more elegant but brutalist examples that I could think of. It is very hard not to love those Skylines! Yet to be honest even though I love that rarity I am partial to the curvier lines of the R33 GTS-T/GT-R myself.... which is much closer to the SC's curved hood design.

I can see you going a hair lower than I am with the Muller coilovers and larger wheels. Since you will, I strongly recommend doing the body harness extension/relocation that affects lowered SC's. Rudy just had a problem with that last month and he was doing perfectly fine for a long time with his suspension adjusted somewhat low until disaster struck. Best to do that preemptively before you get your new coilovers and remade CCW's ready to install.

 

Looking forward to meeting up, Craig.

You scared me with this harness malarkey. I heard people reference it here and there but I thought it only applied to the most slammed cars. I looked around the boards a little and found two threads; one with cutting and extending and one WITHOUT cutting and extending. Have you seen this DIY?

https://www.clublexus.com/forums/per...elocation.html

This looks like my kind of DIY. I could not imagine the stress of cutting that harness and then extending every single wire! I saw the first DIY and had a palpitation seeing 30 or however many wires cut and spliced. What a nightmare! I suppose I’ll add the harness relocation to my list of first-step mods!

I used to have a decent wiring kit. I’ll need to go and find some new stuff out there. I have never been a huge fan of the electric tape look, so maybe I’ll do some braid or heat shrink. Or, the classic loom/electrical tape combo.

Thanks for the heads up!

Nick

 

I spoke with Fortune Auto and dropped my spring rates from 14/10 kg to 12/8 which is their default spec. I figure I can always stiffen things with the adjustment in the damper, but I can’t really make it softer without making the ride kind of bouncy with a full soft setting on the damper. I don’t know if this logic is perfectly sound, but I think with the longer stroke and the adjustable dampers, I should be able to keep the suspension to a comfortable, yet sporty level.

As for wire harness relocation, I saw that some guys are tucking the harness further up in the wheel well. Maybe I will try that since I don’t intend to slam the car?

I also placed my order today for my wheel parts. Final specs on the CCW’s will be:F - 18x9.5” +44 (255/40-18)
R - 18x11” +38 285/35-18)

I found a stupid deal on TireRack for the rear tires, Pirelli P Zero for $165 each! If anyone needs new rears, go take a look!
Sadly, the wheel parts have a 12+ week back order. So, I won’t have anything sexy to show you guys till next year probably. In the meantime I’ll get this tuneup done and my detail. I’ll share before and after photos of the polishing and all that jazz. Should be pretty dramatic.

Nick

 

There is a huge difference in repeatable stopping power from LS400 calipers to Supra TT. I'd go Supra TT if you are serious about making 500+hp. Those brakes can handle that power without any problems with fade and as someone mentioned more pad choices. The TT calipers have hardened steel pistons and high temp seals that will not fade like the LS400 will. LS400 will work fine at stock SC power levels but the second you start making power I can personally guarantee they will not hold up. There is not much price difference between them. Your safety and insurance having good brakes on this much investment going into the car will be a no-brainer. They look and perform similar until you put some power behind them. One is not like the other.

The others run stiffer springs in their coil-overs because when you lower the car the amount of rate rises almost exponentially. You said you wanted close to stock height. Then a Aftermarket coil-over will not work for you. They will ride ok at some speeds and bounce all over at all other speeds. The spring rate has a lot to do with the Natural frequency of the suspension. Factory cars usually have a number between 80-120, and most coil-overs are waaaay over that number. You can make your car slower by going to high. Not to mention ruin the ride quality. Your ability to hook 500+hp will also be affected by this number. If you go to high the compression from power will bounce the car tires over bumps causing the traction control to aggressively cut in if you are using it or blowing off the tires if you are not using TC. Drift cars use super high frequencies for this reason. It makes the car easier to blow off the tires. This is the opposite of what I want for a grip car driven on the street and why I chose Andrew's setup over a coil-over that is compromised.

 

Also I forgot to mention, to make a car handle at that power level, the car's weight balance front to rear and left to right matters more than the type of engine that gives you smooth power. a 700hp V12 or a 700hp V8 the V8 will be better handling and be a lot faster because it will be lighter and rev faster by keeping more weight over the rear tires. Case in point Bentley GT W12TT vs Bentley GT V8TT. The V8 handles much better. The more power the car has, the more weight you need to have on the rear tires static. Stock SC400 is 57/43%. An Ferrari F12 Berlinetta makes 740 hp and it has a 48/52% REAR biased weight distribution. You should be targeting that number more than having some heavy Iron V12 up front because it will not perform like you think it will without traction. Your Aston DBS is 50/50. It has traction problems. The V8 Vantage is 48/52%. It does not have traction issues. The C7 GS is 48/52%. Fortunately Toyota knew enough to make the SC400 a front mid engine design. You might want to rethink how the weight balance will affect the handling. Interesting note the all aluminum 1UZ is 80lbs lighter than the iron 2JZ. let alone the V12.

Traction is an math equation. (Contact patch size area) X (Coefficient of Tire Friction) X (static WEIGHT on the tire) = Traction ability in HP.

To increase traction, you have to increase those three inputs into that formula.

 

^^ Wow, that's quite a contribution! I have been using Andrew's coil-over design for ten years now and I just learned something new about a car's natural suspension frequency. No wonder he wanted to stick with those Bilstein AK (almost the same as the over the counter TRD versions) shocks as the basis of his setup.


It was a bit difficult to get accurate weights for all these engines. Too many people quote figures with transmissions rather than without. After some digging I found these figures:

The 2JZ-GE in full stock trim weighs... I have heard 500lbs-ish but also lower in the 440lb or lighter range without a transmission. Rule of thumb is that a stock 2JZ-GTE weighs about 100lbs more than a GE (due to the weight of the sequential turbo system among other parts) so the 440lb figure may be the closest to true accuracy.

The 2JZ-GTE in full stock trim (with stock twin turbos) weighs 650lbs (assumed with a Getrag V160 attached). Without the V160 attached it is around 540lbs.

The 1JZ-GTE in full stock trim is 645lbs (assumed with an R154 or A340 attached). Without the transmission it is about 478lbs.

I'm not sure if the above weights include a W58 (90lbs), R154 (120lbs), Getrag V160 (112lbs dry) or A340 Automatic (130lbs)

A 1UZ-FE in full stock trim without a transmission weighs about 435lbs.

Here's a video of a 2JZ-GTE with a single turbo setup (much lighter than the stock twin turbo system) being weighed with and without an R154 transmission:


The 1UZ-FE is indeed a bit lighter than a 2JZ-GE but not by too much. It being considerably shorter also helps with its weight distribution. However these cars were designed around both the heavier inline-six turbo engine and lighter V8 engine.

The 1GZ-FE V12 in full stock trim is apparently just under 600lbs with no transmission attached. It's probably close to the same length as the JZ engines and it's only 60lbs heavier than a fully stock 2JZ-GTE and only 122lbs heavier than a fully stock 1JZ-GTE:


The 1GZ-FE is certainly the heaviest engine of the bunch but with a completely redesigned 3D printed aluminum upper intake system and other custom parts I would think at least some of that rough 600lb figure would come down a bit.

 

This site says the 1UZFE is much lighter than those specs @ 364lb and 3UZ is 386lbs
https://www.motorreviewer.com/engine.php?engine_id=103
https://www.motorreviewer.com/engine.php?engine_id=106

I forgot to say that the 1UZFE was originally designed from a IRL/CART engine and has a billion dollars in development. It's the only V8 in the world that doesn't have any hot spots. It's the most balanced cross plane V8 in the world as well. The short stroke small displacement is perfect for a high revving V8. Its the perfect candidate.

Thanks Kahn. Good info. Speaking of N/A V8 making 700hp+ @10,000rpm here is a HPA Academy with a mechanical engineer just aired on this very subject if you are curious. They talked about everything I said in my post in depth.