SC vs Supra engine bay size
06-20-19, 06:55 PM
#1
SC vs Supra engine bay size
I was wondering if someone familiar with both cars could tell me if the engine bays of both cars are the same size, particularly the distance from the motor mounts back to the firewall. I was on YouTube and saw some guys trying to put a 1gz in a Supra but the oil sump wouldn't clear the steering rack and they couldn't move the engine back far enough without hitting the firewall. Just for curiosities sake I'd like to know if there might be more room in the SCs engine bay.
06-20-19, 07:36 PM
#2
They 1991-2000 Z30 (SC) and Supra MKIV share 99.9999999% to 100% same engine bay. As far as I can tell, it's exactly the same engine bay. The MKIV Supra was developed FROM the SC/Soarer Z30 platform and chassis after all.
Mounting points, bolt holes and other accommodations for components that never even came on left hand drive SC's but which do bolt into those same areas on MKIV Turbos and/or JDM Soarer 1JZ's are present within the SC engine bays.
The only major differences are: the mounting perch height for the SC radiators are lower than in the MKIV (easily overcome with DIY rubber spacers when fitting an MKIV style radiato.r into an SC) and it tends to be that when swapping in another JZ engine into an SC it really helps to re-use the engine mounting brackets from the original 2JZ-GE.
Also, SC300's, Soarer Z30's and Supra MKIVs all use the same style oil pans. The crossmembers are the same for all of them so however the 1UZ-FE's oil pan is configured into an SC also would apply to an MKIV just for instance.
Basically whatever that can be tried in an MKIV engine bay with ease or extreme complications will be the same in an SC300/400 engine bay.
Fitting a 1GZ-FE into either chassis is going to be a custom job. Top Secret in Japan did it many years ago. I would look up anything you can on their build.
Mounting points, bolt holes and other accommodations for components that never even came on left hand drive SC's but which do bolt into those same areas on MKIV Turbos and/or JDM Soarer 1JZ's are present within the SC engine bays.
The only major differences are: the mounting perch height for the SC radiators are lower than in the MKIV (easily overcome with DIY rubber spacers when fitting an MKIV style radiato.r into an SC) and it tends to be that when swapping in another JZ engine into an SC it really helps to re-use the engine mounting brackets from the original 2JZ-GE.
Also, SC300's, Soarer Z30's and Supra MKIVs all use the same style oil pans. The crossmembers are the same for all of them so however the 1UZ-FE's oil pan is configured into an SC also would apply to an MKIV just for instance.
Basically whatever that can be tried in an MKIV engine bay with ease or extreme complications will be the same in an SC300/400 engine bay.
Fitting a 1GZ-FE into either chassis is going to be a custom job. Top Secret in Japan did it many years ago. I would look up anything you can on their build.
06-21-19, 06:10 AM
#3
That's pretty much what I figured. There isn't really any benefit to it when you can make the same power with a GTE swap and not have to change anything. If you wanted to get really ambitious you could probably change the front suspension to a Mustang II type but you'd have to be building something crazy to make it worth it.
06-21-19, 12:55 PM
#4
I have never heard of trying to solve the front sump rear sump issue with changing out the front suspension, especially with that of a mustang 2 in anything other than an old hot rod.
The SC and supra share those dimensions, and they the toyota "rear sump" setup for the oil pan.
The 1GZ has a front/mid sump setup. That would work better on something like a gs300 that has a front/mid sump setup, and it would drfinately not fit with that oil pan in the SC properly.
To answer the question you were getting at, the correct thing to do is to make a rear sump pan for the 1GZ, and leave the front suspension alone. It would take much less fab time and people do custom pans all the time.
It would require you to cut and weld the upper pan (or make one from scratch), and make a custom oil pickup.
Changing out the front suspension and front crossmember to something else to accomodate a front sump would also put the steering rack in the wrong place (as in not in line with the 2 wheels where it is right now).
Also, I would run the 1uz v8 all day before messing with the 1GZ, it can't handle much more than stock power without rebuilding the whole thing, so other than the neat factor, its really not very powerfull.
A 1uz/2JZ with even just a small turbo would crush it all day long, and sounds just as good.
Top secret pretty much did a custom everything when they did their swap, and including the pan, rebuilding the bottom end for boost, and I want to say custom intake manifolds cause the stock ones are very tall and SC and supra hoods are very low, which wont let you mount it anywhere other than in the correct position sump wise so it can sit as low as possible.
The SC and supra share those dimensions, and they the toyota "rear sump" setup for the oil pan.
The 1GZ has a front/mid sump setup. That would work better on something like a gs300 that has a front/mid sump setup, and it would drfinately not fit with that oil pan in the SC properly.
To answer the question you were getting at, the correct thing to do is to make a rear sump pan for the 1GZ, and leave the front suspension alone. It would take much less fab time and people do custom pans all the time.
It would require you to cut and weld the upper pan (or make one from scratch), and make a custom oil pickup.
Changing out the front suspension and front crossmember to something else to accomodate a front sump would also put the steering rack in the wrong place (as in not in line with the 2 wheels where it is right now).
Also, I would run the 1uz v8 all day before messing with the 1GZ, it can't handle much more than stock power without rebuilding the whole thing, so other than the neat factor, its really not very powerfull.
A 1uz/2JZ with even just a small turbo would crush it all day long, and sounds just as good.
Top secret pretty much did a custom everything when they did their swap, and including the pan, rebuilding the bottom end for boost, and I want to say custom intake manifolds cause the stock ones are very tall and SC and supra hoods are very low, which wont let you mount it anywhere other than in the correct position sump wise so it can sit as low as possible.
Last edited by Ali SC3; 06-21-19 at 01:02 PM.
06-22-19, 01:37 AM
#5
^^ Everything Ali said.
Long before I got into an SC I was a classic Mustang guy (and I still am at heart). I am very familiar with the common Mustang II front suspension and crossmember swap. It makes sense on the classic 1965-1973 Mustangs and some other cars of the same era into 70's models. Related, it also makes sense to do a custom aftermarket front tubular K-member upgrade to any of the 1979-1993 Mustang "Fox" cars and even the 1994-2004 Mustangs. All of those many eras of Mustangs benefit from vastly improved front suspension setups from stock.
But the SC and MKIV have a truly great front (and rear) suspension design from the factory. It's WAY better than any technology in the Mustang II front suspension. We have excellent double wishbones front and rear!
Ali is right. Like Top Secret you would have to do a custom rear sump oil pan, custom oil pickup, do a custom intake manifold, build the bottom end and cylinder heads for boost and get into forced induction all to be able to justify the work to fit in a 1GZ-FE V12 from a Toyota Century. A 1UZ is not peanuts to make power with but it's still going to be way cheaper and less involved. A 2JZ or 1JZ is even easier and cheaper to make power with... and any JZ engine build will still have more ultimate potential than a 1UZ let alone a 1GZ. Even an LS swap makes more sense than a 1GZ swap.
V12's are awesome, don't get me wrong. They have a beautiful sound when set up right. But this is a lot of work to have the privilege in an SC even if ultimate power and cost invested aren't priorities to you. Top Secret did a 1GZ V12 turbo Supra MKIV mostly to do something different and prove that it could be done with enough effort. But mostly it was to do something different just to be different and insane and have fun with it since they have always been known for extremely unique showcase cars.
At the very least there is zero advantage to changing the SC chassis to fit any engine. The right way is to get the swap engine to fit the SC chassis.
I would say that if money and the time for custom work are not concerns and you really want to be different and go all out with a custom built 1GZ V12 you could make it happen. And done right of course it would be awesome. But if you're even barely considering any of it from a value or cost-benefit standpoint then stop right there because that is not what an extreme 1GZ swap will ever be about.
It is definitely far easier to make reliable power with a 2JZ-GTE swap, 2JZ-GE NA-T build or a 1JZ-GTE swap.
Long before I got into an SC I was a classic Mustang guy (and I still am at heart). I am very familiar with the common Mustang II front suspension and crossmember swap. It makes sense on the classic 1965-1973 Mustangs and some other cars of the same era into 70's models. Related, it also makes sense to do a custom aftermarket front tubular K-member upgrade to any of the 1979-1993 Mustang "Fox" cars and even the 1994-2004 Mustangs. All of those many eras of Mustangs benefit from vastly improved front suspension setups from stock.
But the SC and MKIV have a truly great front (and rear) suspension design from the factory. It's WAY better than any technology in the Mustang II front suspension. We have excellent double wishbones front and rear!
Ali is right. Like Top Secret you would have to do a custom rear sump oil pan, custom oil pickup, do a custom intake manifold, build the bottom end and cylinder heads for boost and get into forced induction all to be able to justify the work to fit in a 1GZ-FE V12 from a Toyota Century. A 1UZ is not peanuts to make power with but it's still going to be way cheaper and less involved. A 2JZ or 1JZ is even easier and cheaper to make power with... and any JZ engine build will still have more ultimate potential than a 1UZ let alone a 1GZ. Even an LS swap makes more sense than a 1GZ swap.
V12's are awesome, don't get me wrong. They have a beautiful sound when set up right. But this is a lot of work to have the privilege in an SC even if ultimate power and cost invested aren't priorities to you. Top Secret did a 1GZ V12 turbo Supra MKIV mostly to do something different and prove that it could be done with enough effort. But mostly it was to do something different just to be different and insane and have fun with it since they have always been known for extremely unique showcase cars.
At the very least there is zero advantage to changing the SC chassis to fit any engine. The right way is to get the swap engine to fit the SC chassis.
I would say that if money and the time for custom work are not concerns and you really want to be different and go all out with a custom built 1GZ V12 you could make it happen. And done right of course it would be awesome. But if you're even barely considering any of it from a value or cost-benefit standpoint then stop right there because that is not what an extreme 1GZ swap will ever be about.
It is definitely far easier to make reliable power with a 2JZ-GTE swap, 2JZ-GE NA-T build or a 1JZ-GTE swap.
Last edited by KahnBB6; 06-22-19 at 01:47 AM.
06-22-19, 05:35 AM
#6
Thanks guys, I just wanted to ask since it would be an amazing swap cool factor wise. Ultimate power isn't my goal, if going fast was my main concern I'd have started with a Mustang or LS something and saved myself some headaches. I guess I'll stick with the Aristo GTE swap I've been planning.
06-22-19, 11:08 PM
#7
^^ I totally agree that a 1GZ V12 fully built and fitted into any popular Toyota is cool in and of itself. It's just a lot of work and money for what you actually get out of it.
The Aristo GTE swap will cost a good chunk in money and time invested but you will already have all the parts and wiring/swap guides readily available to complete it. In that sense all the hard work has already been done for you.
Gerrb's big "wiring harness made easy" thread will help you tremendously if you want to do the harness conversion work yourself. For anything on the mechanical side (and with some minor differences between USDM and JDM 2JZGTE) I laid out just about every step in the rebuilding and servicing of components on a 2JZGTE swap into an SC from the bare block to finish in my own build thread. For wiring though you'll want to instead follow Gerrb's harness thread since he directly covers the Aristo 2JZGTE harnesses.
A 2JZ is half the cylinders of that V12 and far more stout. It has its own beautiful sound when boosted
The Aristo GTE swap will cost a good chunk in money and time invested but you will already have all the parts and wiring/swap guides readily available to complete it. In that sense all the hard work has already been done for you.
Gerrb's big "wiring harness made easy" thread will help you tremendously if you want to do the harness conversion work yourself. For anything on the mechanical side (and with some minor differences between USDM and JDM 2JZGTE) I laid out just about every step in the rebuilding and servicing of components on a 2JZGTE swap into an SC from the bare block to finish in my own build thread. For wiring though you'll want to instead follow Gerrb's harness thread since he directly covers the Aristo 2JZGTE harnesses.
A 2JZ is half the cylinders of that V12 and far more stout. It has its own beautiful sound when boosted
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06-23-19, 11:48 PM
#9
^^ With a 1998 SC300 VVT-i chassis try to find a 1996+ JDM Aristo 2JZGTE VVT-i engine. Gerrb has also covered a lot of notes on that as well. A swap from a VVT-i chassis to a GTE VVT-i is more straightforward than a GTE non-VVT-i.
Just re-use the automatic transmission that will come with the Aristo engine as it was designed for that engine and your 98 SC300's automatic transmission will not handle the power. That GTE A340 4-speed automatic is goo for about 450whp-500whp with a good trans oil cooler added. You can also have it built by ATF to hold about 840whp max (also with a good thorough set of transmission oil coolers-- see Gerrb's build thread for good examples of how to properly keep one of those built GTE A340 automatics cool at 800whp+)
You can pick up an SC or MKIV 2JZ-GE/GTE oil pan (don't forget the correct dip stick, pickup and oil level sensor!) or you can just re-use all of that hardware from your stock GE engine. Drilling out and tapping the un-machined turbo oil drain location with a GE oil pan off an engine is a very straightforward process.
The VVT-i twin turbos you can re-sell. I believe in those model years they finally went away from the earlier ceramic exhaust wheels found on JDM non-VVT-i 2JZ-GTE's but I'm not 100% sure of that. I love the stock sequential twin turbos personally but most would agree with your decision to go with a modern quick spooling single turbo.
At that point you would also want to pick up either an SC400 3.92 open diff (which you can have rebuilt for an LSD) or an increasingly rare Supra TT Auto 3.76 Torsen LSD rear. The higher the power level you are building for above, say, 450-500whp, an aftermarket LSD is recommended. Either way you will at least want to install a 92-97 SC400 rear diff with the 3.92 ratio which will be much better than the 4.27 SC300 rear end once you have a turbo. A Yellr Yellowbox V5 can be fitted with an available SC/MKIV plug and play harness also sold by Yellr which will be able to correct your speedo inaccuracy.
Just re-use the automatic transmission that will come with the Aristo engine as it was designed for that engine and your 98 SC300's automatic transmission will not handle the power. That GTE A340 4-speed automatic is goo for about 450whp-500whp with a good trans oil cooler added. You can also have it built by ATF to hold about 840whp max (also with a good thorough set of transmission oil coolers-- see Gerrb's build thread for good examples of how to properly keep one of those built GTE A340 automatics cool at 800whp+)
You can pick up an SC or MKIV 2JZ-GE/GTE oil pan (don't forget the correct dip stick, pickup and oil level sensor!) or you can just re-use all of that hardware from your stock GE engine. Drilling out and tapping the un-machined turbo oil drain location with a GE oil pan off an engine is a very straightforward process.
The VVT-i twin turbos you can re-sell. I believe in those model years they finally went away from the earlier ceramic exhaust wheels found on JDM non-VVT-i 2JZ-GTE's but I'm not 100% sure of that. I love the stock sequential twin turbos personally but most would agree with your decision to go with a modern quick spooling single turbo.
At that point you would also want to pick up either an SC400 3.92 open diff (which you can have rebuilt for an LSD) or an increasingly rare Supra TT Auto 3.76 Torsen LSD rear. The higher the power level you are building for above, say, 450-500whp, an aftermarket LSD is recommended. Either way you will at least want to install a 92-97 SC400 rear diff with the 3.92 ratio which will be much better than the 4.27 SC300 rear end once you have a turbo. A Yellr Yellowbox V5 can be fitted with an available SC/MKIV plug and play harness also sold by Yellr which will be able to correct your speedo inaccuracy.
06-24-19, 06:15 AM
#10
The goal for the build is about 400hp with as much torque as I can make and getting the power to come in at a useable on the street rpm range. Going single turbo was to eliminate the ceramic impellers in the stock twins but also to have the reliability of something new and to have a smoother power curve. Every dyno chart I've seen of the twins has a dip when the second turbo comes on and it's right where I want things to be getting good at. Plus, eventually the twins are going to die and I'll have to go single anyway so I might as well build it that way from the jump so I dont have to redo significant portions of the build. I'm looking at a 52mm or 55m turbo and the Treadstone manifold. What engine management would be the best for this setup? The place in town that imports JDM engines includes the ecu but going single turbo is there any benefit to trying to run the Aristo ecu?
06-24-19, 03:04 PM
#11
For ECU's I would refer you to Ali SC3 and Gerrb but generally the consensus is that for very mild setups at or below 450whp the JDM Aristo 2JZGTE ECU is going to be a very good fit. You can upgrade from the stock 440cc injectors to 550s I believe. 400hp is very, very easy to gain from a stock 2JZGTE. With my stock 2JZGTE that would be as simple as going BPU. Very easy to get 400hp. The VVT-i version of that engine will certainly help your low end torque and power curve though it is still going to be similar to non-vvt-i.
Honestly for only 400hp you could still use the stock twins in sequential mode. Numerous reputable outfits rebuild those CT20's with steel exhaust wheels and tighter tolerances than stock. And the impeller shafts on the JDM CT20's are actually thicker in diameter than the impeller shafts in the US Supra CT12B turbos.
Gerrb just installed one of those Treadstone manifolds on one of his SC's and showed specifics as to what size turbo could be fitted to it and still clear the SC shock tower. Check out his "...2JZGTE Toys" thread in our Builds section for some ideas.
With the stock sequential twins there is indeed a brief dip at least in the older VVT-i versions. My swap uses USDM OBD1 electronics so I definitely notice it but to me it's not that big of a deal for a mild daily driver SC. The USDM OBD2 Supra TT ECU's reportedly corrected out that momentary torque dip transition that would occur sometime between 3800-4000rpm. JDM 2JZGTE Non-VVT-i's probably had this same characteristic but I would suspect that the 1996-2005 JDM VVT-i 2JZGTE's would have corrected that quirk.
For the mild horsepower level that you seek (assuming you meant 400 crank hp and not 400 wheel hp) you really don't have to change out those turbos.
But I would say that yes you should be able to retain the engine's stock ECU. Easier all around for baseline troubleshooting, automatic transmission control and it should be able to manage the engine's air/fuel well within the 400hp OR 400whp power range which is considered extremely reasonable for these engines with most of their stock hardware. You'll need a Greddy fuel cut eliminator or equivalent (try Driftmotion or Speed For Sale if you can't find one used) and you'll need a Greddy/HKS/whatever speed cut eliminator since the JDM ECU's are factory limited to 112mph.
The rest you should be able to achieve by researching established staged upgrade paths for the 2JZGTE's.
Really, what you are proposing is a very attainable and reasonable SC GTE swap setup especially since you are retaining an automatic. But I do believe the current thinking is that an SC300 VVT-i swaps easiest with a JDM 1JZGTE/2JZGTE VVT-i type engine (with the exception of the drive by wire versions found in late model JDM Toyotas).
Also, take a look at this thread Aristo 2JZGTE CT20 turbos:
https://www.supraforums.com/threads/...rsions.664365/
Honestly for only 400hp you could still use the stock twins in sequential mode. Numerous reputable outfits rebuild those CT20's with steel exhaust wheels and tighter tolerances than stock. And the impeller shafts on the JDM CT20's are actually thicker in diameter than the impeller shafts in the US Supra CT12B turbos.
Gerrb just installed one of those Treadstone manifolds on one of his SC's and showed specifics as to what size turbo could be fitted to it and still clear the SC shock tower. Check out his "...2JZGTE Toys" thread in our Builds section for some ideas.
With the stock sequential twins there is indeed a brief dip at least in the older VVT-i versions. My swap uses USDM OBD1 electronics so I definitely notice it but to me it's not that big of a deal for a mild daily driver SC. The USDM OBD2 Supra TT ECU's reportedly corrected out that momentary torque dip transition that would occur sometime between 3800-4000rpm. JDM 2JZGTE Non-VVT-i's probably had this same characteristic but I would suspect that the 1996-2005 JDM VVT-i 2JZGTE's would have corrected that quirk.
For the mild horsepower level that you seek (assuming you meant 400 crank hp and not 400 wheel hp) you really don't have to change out those turbos.
But I would say that yes you should be able to retain the engine's stock ECU. Easier all around for baseline troubleshooting, automatic transmission control and it should be able to manage the engine's air/fuel well within the 400hp OR 400whp power range which is considered extremely reasonable for these engines with most of their stock hardware. You'll need a Greddy fuel cut eliminator or equivalent (try Driftmotion or Speed For Sale if you can't find one used) and you'll need a Greddy/HKS/whatever speed cut eliminator since the JDM ECU's are factory limited to 112mph.
The rest you should be able to achieve by researching established staged upgrade paths for the 2JZGTE's.
Really, what you are proposing is a very attainable and reasonable SC GTE swap setup especially since you are retaining an automatic. But I do believe the current thinking is that an SC300 VVT-i swaps easiest with a JDM 1JZGTE/2JZGTE VVT-i type engine (with the exception of the drive by wire versions found in late model JDM Toyotas).
Also, take a look at this thread Aristo 2JZGTE CT20 turbos:
https://www.supraforums.com/threads/...rsions.664365/
Last edited by KahnBB6; 06-24-19 at 03:10 PM. Reason: Info correction.
06-25-19, 01:31 AM
#12
Thanks for all your help, I'm definitely sticking with vvti. The low end gains are too good to ignore. I read gerbb's thread a while back but I'll check it out again. I have no intentions of going over 100 mph so the speed cut thing isn't an issue.
06-25-19, 01:59 AM
#13
No problem! Good luck with your swap! The 2JZ-GTE VVT-i head should make a noticeable difference especially if you do stay with your plan to go single turbo (it definitely helps the stock twins also). No need for a speed cut eliminator means just one less thing to do on the electrical side.
You've already done some hard thinking about what you want to achieve and this is good. You can always go for a higher state of tune later if you wish... or not if you wish. Your goals as you have stated are very attainable and "modest" for a 2JZGTE swap (which is to say in real world terms still quite potent but not into bonkers territory).
Keep us posted!
You've already done some hard thinking about what you want to achieve and this is good. You can always go for a higher state of tune later if you wish... or not if you wish. Your goals as you have stated are very attainable and "modest" for a 2JZGTE swap (which is to say in real world terms still quite potent but not into bonkers territory).
Keep us posted!
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