Engine swap? Confused.
10-19-19 | 07:45 AM
#1
Thread Starter
Rookie
Joined: May 2017
Posts: 77
Likes: 3
From: DUBAI
Engine swap? Confused.
Okay so I have ye ole '93 SC400 - love the car but was thinking lately about fuel economy.
Those two do not mix however was wondering a swap to the SC300 engine or something a bit more economical? Open to ideas as crazy as it sounds...
I have a few ideas!
Those two do not mix however was wondering a swap to the SC300 engine or something a bit more economical? Open to ideas as crazy as it sounds...
I have a few ideas!
10-19-19 | 08:42 PM
#2
The 1UZ-FE 4.0L V8 is actually more fuel efficient than the 2JZ-GE 3.0L I6, counterintuitive as that may sound. The difference isn't very much but it's been noted over the years. I am assuming that everything is in good tune and working properly in your car.
For the work involved in swapping in any JZ engine I think the most economical (by a very small margin) might be the 96+ JDM 1JZ-GTE VVT-i w/4-speed automatic left in completely stock form. More power and very good low end response from the CT15B turbo with VVT-i but from only 2.5L of displacement. That stock driveline in JDM Soarers came with the same 3.92:1 geared differential that is already in your '93 SC400.
The side effect would be significantly more horsepower and torque but ultimately the fuel economy gains would be very minimal. The 91-00 SC300/400/Soarer series were never fuel efficient cars to begin with. In the very early 90's their fuel consumption characteristics and premium fuel requirement for a high end personal luxury GT coupe were considered normal for the design and intended customer base. Today their fuel economy is more or less acceptable but not great.
It's a big 3500lb+ *potentially* (if modified) high performance driver-centric GT car. Or it can be a sporty luxury coupe cruiser. These cars drink down fuel when driven hard ALL the time but with their big 20.6 U.S. Gallon gas tanks they do go quite a long distance just cruising along on highways.
To add: the most fuel efficient JZ engines were the 1JZ-FSE (197hp) and 2JZ-FSE (217hp) available only on Japanese domestic market cars. These employed an early implementation of Toyota's D4S direct injection system and which used specific narrow angle cylinder heads with VVT-i on the intake and exhaust cams. These engines were only ever mated to 4-speed and 5-speed automatic transmissions. They did allow the JZ engine design to achieve better fuel economy than any other JZ engine variant made by Toyota but in practical terms it would be tremendous work to swap an FSE variant into an SC and get all the bugs worked out. Their cylinder heads are not considered good for performance applications either.
For the work involved in swapping in any JZ engine I think the most economical (by a very small margin) might be the 96+ JDM 1JZ-GTE VVT-i w/4-speed automatic left in completely stock form. More power and very good low end response from the CT15B turbo with VVT-i but from only 2.5L of displacement. That stock driveline in JDM Soarers came with the same 3.92:1 geared differential that is already in your '93 SC400.
The side effect would be significantly more horsepower and torque but ultimately the fuel economy gains would be very minimal. The 91-00 SC300/400/Soarer series were never fuel efficient cars to begin with. In the very early 90's their fuel consumption characteristics and premium fuel requirement for a high end personal luxury GT coupe were considered normal for the design and intended customer base. Today their fuel economy is more or less acceptable but not great.
It's a big 3500lb+ *potentially* (if modified) high performance driver-centric GT car. Or it can be a sporty luxury coupe cruiser. These cars drink down fuel when driven hard ALL the time but with their big 20.6 U.S. Gallon gas tanks they do go quite a long distance just cruising along on highways.
To add: the most fuel efficient JZ engines were the 1JZ-FSE (197hp) and 2JZ-FSE (217hp) available only on Japanese domestic market cars. These employed an early implementation of Toyota's D4S direct injection system and which used specific narrow angle cylinder heads with VVT-i on the intake and exhaust cams. These engines were only ever mated to 4-speed and 5-speed automatic transmissions. They did allow the JZ engine design to achieve better fuel economy than any other JZ engine variant made by Toyota but in practical terms it would be tremendous work to swap an FSE variant into an SC and get all the bugs worked out. Their cylinder heads are not considered good for performance applications either.
Last edited by KahnBB6; 10-19-19 at 08:52 PM.
10-20-19 | 12:37 AM
#3
Thread Starter
Rookie
Joined: May 2017
Posts: 77
Likes: 3
From: DUBAI
The 1UZ-FE 4.0L V8 is actually more fuel efficient than the 2JZ-GE 3.0L I6, counterintuitive as that may sound. The difference isn't very much but it's been noted over the years. I am assuming that everything is in good tune and working properly in your car.
For the work involved in swapping in any JZ engine I think the most economical (by a very small margin) might be the 96+ JDM 1JZ-GTE VVT-i w/4-speed automatic left in completely stock form. More power and very good low end response from the CT15B turbo with VVT-i but from only 2.5L of displacement. That stock driveline in JDM Soarers came with the same 3.92:1 geared differential that is already in your '93 SC400.
The side effect would be significantly more horsepower and torque but ultimately the fuel economy gains would be very minimal. The 91-00 SC300/400/Soarer series were never fuel efficient cars to begin with. In the very early 90's their fuel consumption characteristics and premium fuel requirement for a high end personal luxury GT coupe were considered normal for the design and intended customer base. Today their fuel economy is more or less acceptable but not great.
It's a big 3500lb+ *potentially* (if modified) high performance driver-centric GT car. Or it can be a sporty luxury coupe cruiser. These cars drink down fuel when driven hard ALL the time but with their big 20.6 U.S. Gallon gas tanks they do go quite a long distance just cruising along on highways.
To add: the most fuel efficient JZ engines were the 1JZ-FSE (197hp) and 2JZ-FSE (217hp) available only on Japanese domestic market cars. These employed an early implementation of Toyota's D4S direct injection system and which used specific narrow angle cylinder heads with VVT-i on the intake and exhaust cams. These engines were only ever mated to 4-speed and 5-speed automatic transmissions. They did allow the JZ engine design to achieve better fuel economy than any other JZ engine variant made by Toyota but in practical terms it would be tremendous work to swap an FSE variant into an SC and get all the bugs worked out. Their cylinder heads are not considered good for performance applications either.
For the work involved in swapping in any JZ engine I think the most economical (by a very small margin) might be the 96+ JDM 1JZ-GTE VVT-i w/4-speed automatic left in completely stock form. More power and very good low end response from the CT15B turbo with VVT-i but from only 2.5L of displacement. That stock driveline in JDM Soarers came with the same 3.92:1 geared differential that is already in your '93 SC400.
The side effect would be significantly more horsepower and torque but ultimately the fuel economy gains would be very minimal. The 91-00 SC300/400/Soarer series were never fuel efficient cars to begin with. In the very early 90's their fuel consumption characteristics and premium fuel requirement for a high end personal luxury GT coupe were considered normal for the design and intended customer base. Today their fuel economy is more or less acceptable but not great.
It's a big 3500lb+ *potentially* (if modified) high performance driver-centric GT car. Or it can be a sporty luxury coupe cruiser. These cars drink down fuel when driven hard ALL the time but with their big 20.6 U.S. Gallon gas tanks they do go quite a long distance just cruising along on highways.
To add: the most fuel efficient JZ engines were the 1JZ-FSE (197hp) and 2JZ-FSE (217hp) available only on Japanese domestic market cars. These employed an early implementation of Toyota's D4S direct injection system and which used specific narrow angle cylinder heads with VVT-i on the intake and exhaust cams. These engines were only ever mated to 4-speed and 5-speed automatic transmissions. They did allow the JZ engine design to achieve better fuel economy than any other JZ engine variant made by Toyota but in practical terms it would be tremendous work to swap an FSE variant into an SC and get all the bugs worked out. Their cylinder heads are not considered good for performance applications either.
First, would any other engine be okay then? Thinking on the broader aspect of perhaps an updated LS400/430 engine but then again wondering how that would go on the gearbox? It opens a whole world of issues but just thinking out loud of what could be done. I used to drive this daily and the fuel consumption started getting to me a bit. I get that this car and fuel consumption do not get along considering what it was built for however just thinking here... could you potentially install another engine that was a bit more fuel efficient alongside a gearbox that had the same purpose? Wondering how would this work if it would work at all.
Second, you mentioned about the 5 speed auto transmissions - would that help fuel economy if I got a 5 speed transmission changed from the current 4 speed? Again I realise the challenge of changing this but an extra gear should help?
I really do not want to sell the car so just looking at what options I got here.
10-20-19 | 01:15 AM
#4
Thank you for your reply, blown away by the amount of information here. Well a few questions!
First, would any other engine be okay then? Thinking on the broader aspect of perhaps an updated LS400/430 engine but then again wondering how that would go on the gearbox? It opens a whole world of issues but just thinking out loud of what could be done. I used to drive this daily and the fuel consumption started getting to me a bit. I get that this car and fuel consumption do not get along considering what it was built for however just thinking here... could you potentially install another engine that was a bit more fuel efficient alongside a gearbox that had the same purpose? Wondering how would this work if it would work at all.
Second, you mentioned about the 5 speed auto transmissions - would that help fuel economy if I got a 5 speed transmission changed from the current 4 speed? Again I realise the challenge of changing this but an extra gear should help?
I really do not want to sell the car so just looking at what options I got here.
First, would any other engine be okay then? Thinking on the broader aspect of perhaps an updated LS400/430 engine but then again wondering how that would go on the gearbox? It opens a whole world of issues but just thinking out loud of what could be done. I used to drive this daily and the fuel consumption started getting to me a bit. I get that this car and fuel consumption do not get along considering what it was built for however just thinking here... could you potentially install another engine that was a bit more fuel efficient alongside a gearbox that had the same purpose? Wondering how would this work if it would work at all.
Second, you mentioned about the 5 speed auto transmissions - would that help fuel economy if I got a 5 speed transmission changed from the current 4 speed? Again I realise the challenge of changing this but an extra gear should help?
I really do not want to sell the car so just looking at what options I got here.
Regarding the 5-speed automatic transmission, I was primarily referring to the Toyota A650E automatic found on 1UZ-FE VVT-i 290hp engines (using the heavy duty version of the A650E) and a slightly weaker version of the same 5-speed automatic with the same model code that came backed on all 2JZ-GE VVT-i engines from about 2001 onward... notably in the 2001-2005 Lexus IS300. It is a very good automatic transmission and much more responsive than the old A340E 4-speed in your SC400. It also contributes a bit to better fuel economy.
The A650E needs to be controlled by a main engine ECU that is programmed for it so it would make more sense to swap a full 1UZ-FE VVT-i w/A650E driveline and the full wiring harness into your 1993 SC400. You'd need to convert the harness to work with your 1993 chassis and you might need a 97-00 gauge cluster swap also (not sure if that is necessary or not). Plus, you'd want to find a 3.26:1 200mm diff from a 98-00 SC400 (companion flange is a direct fit), GS400 (and swap on an SC companion flange) or SC430 (and swap on an SC companion flange).
You also could swap a full driveline from an IS300 2JZ-GE into your SC400 but, again, it's a lot of work for a horsepower downgrade and probably not much in terms of gas mileage savings over the old V8 even with the A650E (weaker version) 5-speed still bolted to that 2JZ-GE VVT-i engine.
Alternatively you could also go more radical and swap in a GM LS 5.7 or 6.0 V8 with an accompanying GM automatic transmission and then match it with a custom driveshaft and the closest available Toyota rear diff ratio. Those engines aren't gas misers but unmodified there might be some efficiency gain. While LSx engine swap kits for SC's are available I think this would also be a lot of work.
If I may ask, what kind of gas mileage numbers are you observing currently?
Bottom line, I think you have some options. You shouldn't expect that you can make your SC400 into a 30+ MPG(U.S.) car but assuming you can source a good used 1UZ-FE VVT-i engine, matching A650E transmission, matching engine wiring harness and ECU and a 3.26:1 200mm rear diff you should be able to consider an upgrade to that driveline and see a little gain in efficiency.
But... as this 1UZ-FE VVT-i swap has been done little and considered a lot more by many SC owners I often hear it suggested that it's simply easier to find a 1998-2000 SC400 that already has all that hardware from the factory.
Yet another idea is to get a proven reliable modern longitudinal layout (front to back) new engine that is 2.0L and above with a factory turbo and outputting at least 250+ hp. The wiring and ECU would be a challenge but if you got something like a modern Camaro 2.0L turbo 4cyl or modern Mustang 2.3L turbo 4cyl or Hyundai G70 2.0L turbo 4cyl you could have more fuel economy from any of those.
But... a LOT of unproven swap work would be involved. I would even venture a guess that it would be easier to swap in and wire an imported 2JZ-FSE engine since it would have older wiring and an older ECU plus the SC chassis would already accept a 2JZ block with no cutting required. And without question it would be far easier to swap in a 1JZ-GTE VVT-i engine and transmission since it's a popular swap and the support and documentation to do it is plentiful already.
^^ From 2.5L with variable valve timing, a responsive stock turbo and matching turbo-spec A340E 4-speed auto I do think, given non-aggressive driving habits, you would see at least minor fuel efficiency gains.
The more custom fitting of anything that is needed then the more expensive the swap becomes. By sticking to any existing engine blocks that the chassis already has provisions to mount into it is probably best.
Last edited by KahnBB6; 10-20-19 at 01:26 AM.
10-20-19 | 07:43 AM
#5
Thread Starter
Rookie
Joined: May 2017
Posts: 77
Likes: 3
From: DUBAI
Since your goals do not necessarily focus on adding more power then the answer is that, sure, any other engine could be fitted. It is just a matter of how much work and cost that will involve for you.
Regarding the 5-speed automatic transmission, I was primarily referring to the Toyota A650E automatic found on 1UZ-FE VVT-i 290hp engines (using the heavy duty version of the A650E) and a slightly weaker version of the same 5-speed automatic with the same model code that came backed on all 2JZ-GE VVT-i engines from about 2001 onward... notably in the 2001-2005 Lexus IS300. It is a very good automatic transmission and much more responsive than the old A340E 4-speed in your SC400. It also contributes a bit to better fuel economy.
The A650E needs to be controlled by a main engine ECU that is programmed for it so it would make more sense to swap a full 1UZ-FE VVT-i w/A650E driveline and the full wiring harness into your 1993 SC400. You'd need to convert the harness to work with your 1993 chassis and you might need a 97-00 gauge cluster swap also (not sure if that is necessary or not). Plus, you'd want to find a 3.26:1 200mm diff from a 98-00 SC400 (companion flange is a direct fit), GS400 (and swap on an SC companion flange) or SC430 (and swap on an SC companion flange).
You also could swap a full driveline from an IS300 2JZ-GE into your SC400 but, again, it's a lot of work for a horsepower downgrade and probably not much in terms of gas mileage savings over the old V8 even with the A650E (weaker version) 5-speed still bolted to that 2JZ-GE VVT-i engine.
Alternatively you could also go more radical and swap in a GM LS 5.7 or 6.0 V8 with an accompanying GM automatic transmission and then match it with a custom driveshaft and the closest available Toyota rear diff ratio. Those engines aren't gas misers but unmodified there might be some efficiency gain. While LSx engine swap kits for SC's are available I think this would also be a lot of work.
If I may ask, what kind of gas mileage numbers are you observing currently?
Bottom line, I think you have some options. You shouldn't expect that you can make your SC400 into a 30+ MPG(U.S.) car but assuming you can source a good used 1UZ-FE VVT-i engine, matching A650E transmission, matching engine wiring harness and ECU and a 3.26:1 200mm rear diff you should be able to consider an upgrade to that driveline and see a little gain in efficiency.
But... as this 1UZ-FE VVT-i swap has been done little and considered a lot more by many SC owners I often hear it suggested that it's simply easier to find a 1998-2000 SC400 that already has all that hardware from the factory.
Yet another idea is to get a proven reliable modern longitudinal layout (front to back) new engine that is 2.0L and above with a factory turbo and outputting at least 250+ hp. The wiring and ECU would be a challenge but if you got something like a modern Camaro 2.0L turbo 4cyl or modern Mustang 2.3L turbo 4cyl or Hyundai G70 2.0L turbo 4cyl you could have more fuel economy from any of those.
But... a LOT of unproven swap work would be involved. I would even venture a guess that it would be easier to swap in and wire an imported 2JZ-FSE engine since it would have older wiring and an older ECU plus the SC chassis would already accept a 2JZ block with no cutting required. And without question it would be far easier to swap in a 1JZ-GTE VVT-i engine and transmission since it's a popular swap and the support and documentation to do it is plentiful already.
^^ From 2.5L with variable valve timing, a responsive stock turbo and matching turbo-spec A340E 4-speed auto I do think, given non-aggressive driving habits, you would see at least minor fuel efficiency gains.
The more custom fitting of anything that is needed then the more expensive the swap becomes. By sticking to any existing engine blocks that the chassis already has provisions to mount into it is probably best.
Regarding the 5-speed automatic transmission, I was primarily referring to the Toyota A650E automatic found on 1UZ-FE VVT-i 290hp engines (using the heavy duty version of the A650E) and a slightly weaker version of the same 5-speed automatic with the same model code that came backed on all 2JZ-GE VVT-i engines from about 2001 onward... notably in the 2001-2005 Lexus IS300. It is a very good automatic transmission and much more responsive than the old A340E 4-speed in your SC400. It also contributes a bit to better fuel economy.
The A650E needs to be controlled by a main engine ECU that is programmed for it so it would make more sense to swap a full 1UZ-FE VVT-i w/A650E driveline and the full wiring harness into your 1993 SC400. You'd need to convert the harness to work with your 1993 chassis and you might need a 97-00 gauge cluster swap also (not sure if that is necessary or not). Plus, you'd want to find a 3.26:1 200mm diff from a 98-00 SC400 (companion flange is a direct fit), GS400 (and swap on an SC companion flange) or SC430 (and swap on an SC companion flange).
You also could swap a full driveline from an IS300 2JZ-GE into your SC400 but, again, it's a lot of work for a horsepower downgrade and probably not much in terms of gas mileage savings over the old V8 even with the A650E (weaker version) 5-speed still bolted to that 2JZ-GE VVT-i engine.
Alternatively you could also go more radical and swap in a GM LS 5.7 or 6.0 V8 with an accompanying GM automatic transmission and then match it with a custom driveshaft and the closest available Toyota rear diff ratio. Those engines aren't gas misers but unmodified there might be some efficiency gain. While LSx engine swap kits for SC's are available I think this would also be a lot of work.
If I may ask, what kind of gas mileage numbers are you observing currently?
Bottom line, I think you have some options. You shouldn't expect that you can make your SC400 into a 30+ MPG(U.S.) car but assuming you can source a good used 1UZ-FE VVT-i engine, matching A650E transmission, matching engine wiring harness and ECU and a 3.26:1 200mm rear diff you should be able to consider an upgrade to that driveline and see a little gain in efficiency.
But... as this 1UZ-FE VVT-i swap has been done little and considered a lot more by many SC owners I often hear it suggested that it's simply easier to find a 1998-2000 SC400 that already has all that hardware from the factory.
Yet another idea is to get a proven reliable modern longitudinal layout (front to back) new engine that is 2.0L and above with a factory turbo and outputting at least 250+ hp. The wiring and ECU would be a challenge but if you got something like a modern Camaro 2.0L turbo 4cyl or modern Mustang 2.3L turbo 4cyl or Hyundai G70 2.0L turbo 4cyl you could have more fuel economy from any of those.
But... a LOT of unproven swap work would be involved. I would even venture a guess that it would be easier to swap in and wire an imported 2JZ-FSE engine since it would have older wiring and an older ECU plus the SC chassis would already accept a 2JZ block with no cutting required. And without question it would be far easier to swap in a 1JZ-GTE VVT-i engine and transmission since it's a popular swap and the support and documentation to do it is plentiful already.
^^ From 2.5L with variable valve timing, a responsive stock turbo and matching turbo-spec A340E 4-speed auto I do think, given non-aggressive driving habits, you would see at least minor fuel efficiency gains.
The more custom fitting of anything that is needed then the more expensive the swap becomes. By sticking to any existing engine blocks that the chassis already has provisions to mount into it is probably best.
If I have any more questions (after my research) I'll post them here!
10-21-19 | 12:13 AM
#6
No problem! Glad if I've helped a bit.
Please keep in mind that the very newer engines I mentioned such as the turbo four cylinders have to my knowledge never been attempted as swaps into an SC. Once on this forum I jokingly suggested a Pontiac Solstice GXP or Saturn Sky Redline engine which is a 2.0L turbo 260hp engine capable of a 290hp tune from GM simply because it can easily bolt up to a swapped in R154 5-speed manual transmission from other Toyotas... but that engine is not the most reliable compared to the 1UZ-FE or any 1JZ or 2JZ. And then there is the high complexity of the swap if your local government requires all of the emissions equipment for your donor engine to be swapped over as well.
The 98-00 1UZ-FE VVT-i w/A650E automatic and 3.26 differential will be a project to swap over and wire up but it will be one of the more straightforward swaps you can do besides a 1JZ-GTE swap. I can't give you hard numbers but I would still reason that a stock 2.5L turbocharged 1JZ-GTE VVT-i w/matching heavy duty A340 4-speed automatic and your stock 3.92 gear ratio might still provide better fuel economy off-boost because you'd be comparing a 4.0L engine to a 2.5L engine.... however that V8 setup was designed around a 3.26:1 final drive ratio and it tends to rev low on the highway so perhaps it is somewhat close in MPG.
I also feel that a stock GM LS1 or LS2 swap (around 300-400hp stock unmodified depending on generation) with the matching automatic transmission and the closest final drive ratio you have available will also be easier to swap over just due to the existing support for this.
For engine harnesses there are several outfits in the USA who specialize. Tweak'd and Panic-Wire are a couple. In Dubai or in neighboring cities there are surely similar specialists who do custom wiring harnesses for engine swaps. You'd just need the pinouts of the SC400 and for the car you'd be getting the donor engine from.
The newer the engine the more likely it would be that you'd have to get some CANBUS functions working if using the donor car's original ECU. The 92-00 SC series is all pre-CANBUS. Our cars just use classic electrical connections and individual ECUs for various systems in the car in addition to the main engine ECU.
So for an engine swap that comes from a vehicle that uses CANBUS you would likely need to have your custom swap harness based around an aftermarket programmable ECU. It just depends on the engine system you'd be switching to.
This is why the tried and true popular swaps for 92-00 SC's are 1JZ, 2JZ, 1UZ and GM LSx engines. There is a lot of aftermarket support for all of those.
Please keep in mind that the very newer engines I mentioned such as the turbo four cylinders have to my knowledge never been attempted as swaps into an SC. Once on this forum I jokingly suggested a Pontiac Solstice GXP or Saturn Sky Redline engine which is a 2.0L turbo 260hp engine capable of a 290hp tune from GM simply because it can easily bolt up to a swapped in R154 5-speed manual transmission from other Toyotas... but that engine is not the most reliable compared to the 1UZ-FE or any 1JZ or 2JZ. And then there is the high complexity of the swap if your local government requires all of the emissions equipment for your donor engine to be swapped over as well.
The 98-00 1UZ-FE VVT-i w/A650E automatic and 3.26 differential will be a project to swap over and wire up but it will be one of the more straightforward swaps you can do besides a 1JZ-GTE swap. I can't give you hard numbers but I would still reason that a stock 2.5L turbocharged 1JZ-GTE VVT-i w/matching heavy duty A340 4-speed automatic and your stock 3.92 gear ratio might still provide better fuel economy off-boost because you'd be comparing a 4.0L engine to a 2.5L engine.... however that V8 setup was designed around a 3.26:1 final drive ratio and it tends to rev low on the highway so perhaps it is somewhat close in MPG.
I also feel that a stock GM LS1 or LS2 swap (around 300-400hp stock unmodified depending on generation) with the matching automatic transmission and the closest final drive ratio you have available will also be easier to swap over just due to the existing support for this.
For engine harnesses there are several outfits in the USA who specialize. Tweak'd and Panic-Wire are a couple. In Dubai or in neighboring cities there are surely similar specialists who do custom wiring harnesses for engine swaps. You'd just need the pinouts of the SC400 and for the car you'd be getting the donor engine from.
The newer the engine the more likely it would be that you'd have to get some CANBUS functions working if using the donor car's original ECU. The 92-00 SC series is all pre-CANBUS. Our cars just use classic electrical connections and individual ECUs for various systems in the car in addition to the main engine ECU.
So for an engine swap that comes from a vehicle that uses CANBUS you would likely need to have your custom swap harness based around an aftermarket programmable ECU. It just depends on the engine system you'd be switching to.
This is why the tried and true popular swaps for 92-00 SC's are 1JZ, 2JZ, 1UZ and GM LSx engines. There is a lot of aftermarket support for all of those.
Thread
Thread Starter
Forum
Replies
Last Post